Vorshlag Track BMW E46 Development Thread

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DRIVETRAIN INSTALLED

We had a bit of a dead line for a "show and tell" meeting with a supplier in February 2020, who needed to see this race car. It was a good incentive for us to push harder and get more things done to the E46 - like installing an LS engine, installing suspension, having the cage mostly done, nose mounted, etc.



We had the "backup" aluminum 5.3L long block up at HPR but brought it back and mounted a real road race style oil pan to the engine, then stuck it into the car.




Of course we had a bunch of LS swap parts we sell to use for this, but luckily we had some early prototype headers, our original prototype mounts, and a few other leftovers to use. This Summit steel road race oil pan above fits with miles to spare - something we wanted to test on this E46 swap anyway.



We built our shop 2015 Mustang #LS550 swap around this oil pan, and it seems to fit anywhere the 1998-02 Camaro pan or any of the Holley LS pan fit. We will test this in this road race setup on both the 5.3L and the 6.3L stroker that will go in later. With a wet sump oiling system and an Accusump, of course.



Great fit on the kick-out style oil pan, so we'll keep that. The oil filter mount comes off for use with a remote filter and oil cooler, which we will show later. Found these tall LS valve covers with the "CHEVROLET" script, and we will use these with remote coil mounting.



This is a Gen IV truck engine - which all come with DOD features we have to bypass. This requires a unique upper cover (ICT Billet, shown above), and Gen III style front cover, timing chain, cam shaft, and lifters. We're going to do initial testing with this 5.3L so we're getting it ready.



Then we installed the Dorman "LS2" intake and a 90mm DBW throttle body. Then a set of our E46 stainless long tube headers.



That's as far as we got for the show and tell - the motor has since been removed and then reinstalled with a new transmission.

E46 M3 SUBFRAME WORK

As I mentioned last time, we had a few 210mm M3 diff housings (which come with limited slip differentials from the factory) and two complete E46 M3 rear subframe assemblies, as shown below left. Everything on the E46 M3 version is stronger - the differential housing, trailing arms, rear brakes, and more. The E46 non-M rear subframe (see below right) has a number of disadvantages.



In the long run it will be more cost effective for us to convert our 330Ci chassis to use the E46 M3 rear subframe and M3 diff than to convert the 188 mm Medium Case E46 housings to limited slip.



Since none of the "non-M" E46 cars ever came with a limited slip, and many of those medium case housings have a ring gear welded to the diff case, it can get pretty costly to convert one to limited slip. I've done this conversion on non-M E46 cars a few times and it is always shocking how costly this is to do. The differential mounts on the non-M case are also different, and less than ideal (see above right). The available gear ratios on the larger M3 housing also work better for our V8 engine. We will be beefing up even the M3 bits, and will show the various steps below.

STITCH WELDING, REINFORCEMENT, AND POWDER COATING SUBFRAME

We have a few complete E46 M3 rear subframe assemblies, brake to brake. We buy these when they come up for sale, and in one case we had a rusty version that was in a northern car that we picked up cheap. We took the ugliest of our available rear subframe assemblies apart to use for this project.



This involved removing all of the subframe bushings, shown above left. This took a little work but they came out relatively uneventfully using our many BMW specific bushing tools.



You can see the rusty surface of this subframe housing, above. It wasn't deep rusty, just ugly surface stuff. I took this and dropped it off to be bead blasted in November 2019. We got it back in mid December but didn't get a chance to work on it further until January 2020.

SEALED SPHERICAL RTAB BUSHINGS

While the subframe was coming apart we decided to test a new product we had found. The Rear Trailing Arm Bushing (RTAB) on the BMW E36 and E46 chassis is a complicated joint that has to pivot and rotate in 2 different axis.



We don't use polyurethane in this joint, ever. Instead, for the past 16 years we've been in business, we press in an OEM rubber bushing + our RTAB "limiters", which we machine from UMHW for its self-lubricating properties - as shown above. This limits how much toe change can happen with full articulation of this rear trailing arm. A better solution for a race car is to use an aftermarket spherical metal bushing assembly here. The former works well on street and dual purpose cars, the latter not so much. A little road grit + rain will quickly wipe out an all metal bushing located so close to the ground.



For this build we wanted to try a new "sealed" spherical bushing that Jason found. This should give us the best of both worlds. Water proofing a spherical bushing (like BMW does for some other rear suspension locations) would allow for full articulation in 2 axis, without the rattle and bang that worn sphericals give you in a short amount of street driving. Tim removed the M3 rear trailing arms (above left) from the subframe, then Myles and Jason pressed out the old bushings.



We found an OEM replacement sealed spherical that was almost the right size and we made it work in this location. It wasn't easy, and it took some custom machine work and some other compromises. For now we're not releasing what we did or offering this as a kit to sell until we can test this car on track. With a little bit of work we think we can make this easier to install for the DIY crowd.



We installed and fitted the bushings on the two sides two different ways, testing two methods. It was "more than a press fit" getting the spherical housing into the Rear Trailing Arm. Once we got the fit where we liked it, they were both pressed into the arms with the giant C-clamp bushing press shown.



For now this isn't an easy "DIY" job but we're working on some other ways to make this work better. The articulation is perfect (above right) and should be the right solution for E36 and E46 chassis cars, once we can make the bushing more perfected for this application. More on this later.

REAR SUBFRAME REINFOCEMENT

There were a number of things I wanted us to stitch weld as well as some reinforcements to make.



Up first was a pair of brackets that held the rear swaybar. Nobody makes a reinforcement kit for the E46 M3 subframe so Myles drew up and CNC cut out these plates above.



Likewise the two rear differential cover mounting brackets looked a little underwhelming, so I asked Myles to make the brackets above.



After he made some cardboard templates and we discussed a number of tweaks it was time to turn them into CAD drawings then CNC cut them on the plasma table. After they are cleaned up and bent they fit these locations well. After showing the picture above a number of folks reached out and we have made this E46 M3 kit available.



Myles TIG welded these reinforcements to the 4 locations we wanted to strengthen, then stitch welded a few spots that the factory skip weld. This is part of why we bead blasted the whole subframe - it makes for cleaner welds, shows any flaws hidden under the factory paint, etc.

REAR SUBFRAME AND DIFF BUSHING INSTALL

After we got the rear subframe back from powder coating it looks beautiful. We rounded up a set of Powerflex "race polyurethane bushings for the subframe (4) and differential mounts (3). Some might find our choice of poly unusual, as there are Delrin and even aluminum options for all of these locations. Well having done all of that before we knew that this option would give us the least NOISE while controlling any unwanted movement. Aluminum bushings in particular make for a lot of loud crashing and banging, which can be unsettling in an 8-24 hour race, over and over.



Brad pressed in the bushings into the housing (above left), which had already been removed before blasting. The diff housing was then tackled with some special tools we have just for these 3 locations.



Two of the bushings for the M3 housing are in "ears" that extend out from the aluminum rear cover. These are relatively easy to get to. The front bushing is near the pinion flange and goes in the right side - it is pressed into the subframe assembly, and is a little trickier to get to. The diff housing then bolts through this bushing to mount the front.



With all of the bushings pressed into the subframe and diff housing it was time to joint them together, shown above and below.



This selection of "harder" durometer polyurethane bushings should provide the control needed between these two pieces, which normally rock and roll around on very soft OEM rubber bushings. This movement, of both the diff to the subframe and the subframe to the chassis, is what causes so much flexing of the sheet metal tub - which leads to cracks that have to be repaired. We will fix this by adding reinforcements to our chassis in a later update, of course.

3D SCAN + E46 SEAT BRACKET DEVELOPED

One of my goals for this project it to develop new products - and one area we have been pushing into lately is seat brackets. I moved us into this arena reluctantly, but since many of the chassis-specific seat base bracket offerings out there are so terrible (too tall, too flexible, not safely built) that I felt we were doing the community a disservice by staying out of this area.



I wrote this forum thread last year explaining the "what, why and how" of our unique form of seat brackets. We have made these for 5 different chassis now and will be offering the E46 versions soon after I post this. We make these to bolt to the chassis, have mounting holes for lap and anti-sub belt anchors, and leave a swatch of metal that the end user drills and bolts their side brackets (fixed) or sliders to. All of these designs are minimally tall and have reinforcing ribs underneath, and we make them 100% in-house with CNC cut parts, TIG welding them on production fixtures.



We normally take manual measurements of each chassis' four factory mounting holes, but this time we were willing to try some new technology - 3D scanning. A helpful sales tech came by to demo his scanning products and used this chassis for the test. What it gave us was a point cloud that we could then translate into a CAD design. Don't know if it really saved much time, but it was cool watching this tool being used.



Myles turned that into a working prototype, which he CNC cut and we tested in the car (above left). The E46 chassis is pretty narrow and what he realized pretty quickly when this prototype was placed in the car is - we usually offset a racing seat pretty far towards the tunnel. The factory steering wheel isn't even centered on the factory BMW seat. So I worked with him on version 2, which has this offset built in, that he cut, tested, then welded in the reinforcing ribs for (above right).



Tim worked on the sliders and side brackets, which were tested on the seat, then the holes were transferred to the bracket (above right) and the sliders + brackets were bolted into the car. So we have one seat mounted. As soon as we make the passenger side version (they are sometimes mirror images of the driver's side, sometimes now) we will release this as a bracket to sell.

NEW DAMPER SET - MCS TRIPLES

For the past several months our E46 had been up on jack stands and stuck in this cramped work bay. This was because we had removed all of the OEM suspension and had only mocked up up one front corner with a strut/spring/top mount. This let us work on the big brake kit there but we needed to get this car down on the ground and mount up some wheels and tires to move forward in the build. This meant we needed a set of coilover shocks.



We had put out the ask for a little while, and MCS came through in a big way. Getting triple adjustable MCS dampers for this car was the culmination of a lot of hard work, a long record of MCS sales and race wins using their parts, and a little begging.



Normally we will stretch our budget to go for internal doubles (TT2) or remote double (RR2) adjustables on our shop owned cars - which tend to be focused on Time Trial and autocross competitions. My S550 Mustang has RR2s, as does my wife's Optima entry, an LS powered 86. But MCS felt that the triple adjustables were worth it on this endurance road race car.



The triple adjustables give us low speed Rebound, low speed Compression and high speed Compression adjustments. This is especially helpful on a Wheel to Wheel race car where "defending your line" means using a bit more curbing than you would in a TT or HPDE car. The rear shocks are setup to run as a coilover, which we normally don't do for various reasons on the E46 or especially E36 chassis BMWs.



We got to work quickly installing these onto our E46. The front was a simple bolt-on affair with springs we had on hand. We needed that end on to be able to spec the front wheels - which we try to keep as far inboard and as close to the strut as possible.

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Out back was a bit trickier. MCS wanted us to run their inverted, eye-to-eye style rear shock with a 22mm shaft and coilover spring mounting, using a dual / helper spring setup to keep the tire loaded - even at full droop.



This required the use of the MCS "eye" upper shock mount, which bolts into the stock shock tower (see below). Brad mounted that and I was happy with how much inboard wheel clearance we still had. Whew!



This type of spring mounting can sometimes compromise inboard wheel room - a coilover rear on the E36 chassis absolutely will eat up tire room, but the E46 chassis does not suffer from this space constraint. We will need to reinforce the rear shock tower to take full suspension loads, instead of just damper loads, however. We have some ideas and will share that work in a future update.



Brad handled this MCS install in early February 2020, which let us mount the 17x10" wheels and roll the car out of that back bay for the first time in months. Big step, seeing the car down on 4 wheels and rolling again!

FLARES ON & 18X11 WHEELS ORDERED

Shortly after getting the suspension installed we were able to get the E46 over to a 2-post lift and up in the air.



I asked Brad to temporarily tape the Clinched flares (we showed last time) to the car at both ends on the driver's side. These are made to be "trimmed to fit" the contours of your car, and this is where the look and fit of these will improve. For now we're just taping them in place.



This let Jason come out and inspect the clearance inboard, outboard, and relative to the flares. These flares are going to be big enough for our 18x11" wheel and 315/30/18 (or thereabouts) 200 treadware tire package.



The test wheels shown here are NOT our final race wheels, and they are already 10" wide. We're looking to add another inch of wheel width and a good bit more tire. The "stock vs flared" pictures above should show how much room we gain with these flares. Jason was able to spec the wheels so that the same set can be used front and rear (fewer spares needed, and they can rotate) with a 12mm spacer up front, which is normal for most BMW wheels. These wheels were ordered from Forgestar before their additional bespoke wheel charge came into effect, which was a bit of a surprise in March 2020 when that came down.

RADIATOR SUPPORT + HEADLIGHTS MOUNTED

We had been debating head lights to use and how to mount them. The factory "radiator core support" (shown below) is the easiest way to mount the headlights, but it has a bunch of structure we don't need. We have bought a number of these over the years from the import suppliers and they all worked just fine. Looking through our pile of spares we had another brand new one in stock, so we decided to splurge the $55 already spent and use it.



Our car didn't come with one, as it had been in a front end hit. These are pretty common to replace after any small accident, and BMW keeps them painted black no matter what color E46 they made. It didn't take Evan more than a few minutes to bolt this in place, then we started looking at the extra plastic clips and mounts needed to bolt the headlights in place.



Instead of ordering a half dozen special clips from Germany we decided to add nutserts into those square holes in the core instead. Evan drilled the square holes round, then installed some M5 rivnuts. We used some old headlights to make sure they lined up and they did.



The radiator support was then cut up quite a bit - looking for room to fit the radiator. Our goal was to open up a narrow spot and then shove a wider than stock radiator and roll it forward into all of this area we added by making a tubular bumper beam. Unfortunately the headlights themselves are wide and we don't gain a lot of room between the lights to roll the radiator into. But we did remove a lot of structure that was blocking airflow.

The "mock-up" headlights we had on hand were fitted in place when the rivnuts were being added. These looked rough, and were some old OEM units we had leftover from a customer's build when we installed new headlights and turn signal housings on his M3. Tim wondered - can we clean these up and use them? I was doubtful...



Now for headlights I was ready to spend a few hundred on some nice aftermarket replacements but these aren't really needed on this race car. The halos, the smoked turn signals, not really worth it. These are some I purchased for another E46 we covered in this same thread, years ago.



Brad brought out his headlight polishing kit and got started wet sanding and polishing the lenses...



They cleaned up pretty well, surprisingly. Enough to not be an eye sore for our "show and tell". I still might buy some new lenses later (they are amazingly inexpensive) and we can install those with some very bright LED bulbs from Diode Dynamics. Possibly even some yellow XPEL film to protect the new lenses. Will show more here another time.

SHOW & TELL / WEIGHT CHECK FEB 2020

Many months of work and a bit of a thrash in January and February came to a head when we got the car on the ground, on MCS dampers, with an LS engine and headers installed, wheels and tires on and rolling, headlights, M3 bumper cover, bumper beam, and the red steel hood installed.



Since we had the car on the lift we installed one of the Sparco race seats, a radiator, stuck both doors in the back, the heater box (which I haven't showed yet) was set inside, and the electric steering column (also not shown much) was bolted in place. This car has both front 14" rotors and one of the Brembo calipers, and the E46 M3 rear rotors are installed. All of the tubes from the cage kit were inside the car, if not welded in place already. Still has the old non-M subframe and diff, for now. We even loaded the clutch, flywheel and pressure place inside. A Mishimoto radiator was set on top of the engine, and a 22 circuit wiring harness was placed into the trunk, too. Then we got this weight.



2112 pounds was lower than any of us guessed, but a decent amount. We're still missing the the transmission + bellhousing, windshield, driveshaft, swaybars, plumbing, fuel tank + fluids, and the larger E46 M3 diff housing is going to be heavier than the medium case in the car now. But the steel hood and trunk are being replaced with carbon, which will save a little. So we're off by 200-300 pounds. Still, it was a very encouraging number.



Due to this latest weight check we have a good idea of where we will end up now, and this is helping us make smarter decisions as we wrap up the build. We will of course keep taking weights and posting them, even if the car is incomplete. These data points have been helpful to some.

THE CARBONING!

On March 3rd I was working late and a freight truck arrived at 7 pm, in the dark, while raining. I had to scramble a bit to get the fork lift hooked up and unload this big pallet of carbon fiber parts. I dubbed it "The Carboning!" and was as excited as a kid on Christmas.



We unloaded the pallet the next day and unboxed all of he Anderson Composites and Seibon parts. These are two sides of the same company, with Anderson being their domestic car arm and Seibon the import car arm. For our S550 Mustang I received a carbon trunk and carbon doors, shown above.



For our BMW E46 project we got a carbon hood and a carbon trunk. The quality and finish on all of these was great. These Seibon pieces are not "dry carbon" motorsports parts (which they also make) but their more affordable carbon-over-fiberglass / shiny gel coat versions. Still lighter than stock, but not as light as you could see.



Of course we took weights on everything. On the trunk we went from a 27.7 pound steel unit to a 15.6 pound carbon unit. That's a 12.1 pound drop, or a savings of 43%.



The steel 330 hood was 44.5 pounds, and the carbon version was 24.2 - for a drop of 20,3 pounds and a savings of 46%.



In addition the new hood is the "bulged" M3 style and includes a set of carbon grills (which are removable) as well as four massive, carbon vent panels (also removable). The outside carbon surfaces are very glossy and the weave is laid out nicely.



Brad installed the Seibon trunk in about a half hour, just needing to shim the hinges a bit to get the body lines perfect. This required zero sanding or trimming of the actual part, which is pretty rare for composite parts.



Jason and I spent about an hour and a half fitting the hood. This was mostly due to the poorly aligned front fenders, which had huge gaps to the steel hood. We slotted some of the mounting holes there and got the body lines pretty darned good, too. Really looks good with this carbon installed, of course.

LED TAIL LIGHTS, SUNROOF PANEL, PEDALS

This car was missing anything and everything of value, and that included the pedals. After getting a loaner set that I had to give back I broke down and ordered a clutch/brake pedal assembly for $102 shipped from eBay. Tim got those installed on a work night pretty quickly. Installing those allowed us to bolt on the E46 brake booster we had, on the other side of the firewall.



We found an SSR fiberglass sunroof panel that I had ordered back in 2015 for another E46 coupe, and this will be used on this car now.



Another missing part on this chassis were the rear tail light housings, along with the trunk mounted reflectors. I bought a set of the brighter LED versions for this E46 coupe.



Tim installed these into the carbon trunk in early March - nothing tricky here, just a straight bolt-in. As we have done before, we will "direct wire" these around the CAN network that normally controls these brake/tail/turn/reverse lights. We're replacing the entire wiring harness on this chassis.



This set of LED tails + carbon trunk really set off the back of the car. We have a new, fake, custom license plate we will add and show next time, too.

WHAT'S NEXT?

That's a big chunk of work to cover this time. We have other work that has been completed but we're not ready to show all of that just yet - like a brand new crossmember to support a new transmission for this E46 LS swap. Lots of parts have arrived for the front suspension, too.



New inner/outer tie rods, Lower Control Arms, and these LCA bushings from Whiteline with a 2-piece bushing (that allows for proper articulation). We're using this car as a test bed, remember - and this is a new part to us. Rear subframe reinforcement work needs to be done, exhaust needs to be built, and more.



At the same time as this E46 endurance car update was written we also posted an update on our GMT800 shop truck build thread, which went through a ton of changes. You can read that here.

Until next time... thanks for reading!

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Project update for September 23rd, 2020: It has been 6 months since my last post here, and not a lot of things went according to plan. We got crazy busy during the pandemic, lost some manpower, but we are still working on our E46 endurance car a little every week. I spent part of Labor day weekend writing this update to catch us up to the present, which helped me realize I needed to order a few missing parts, as well as update some product entries for things we sell for E46 models. Then I got busy and had to re-start my write-up again.



There is some progress to share, with some "backwards" progress in one area, and nothing happened as fast as we liked. As racing resumed, so did the pro racing support schedule for two of our team members, Tim and Magan, who regularly travel to events for trackside support. "Luckily" none of the other Vorshlag shop cars are complete so I wasn't out for almost any of 2020 going to races (this actually sucked). More time to work on this car - and more motivation.

MOCK-UP ENGINE REMOVED

After our show-and-tell with the E46 we pulled the mockup engine out for the last time. We had the new transmission crossmember developed, test fit two new oil pans, and learned a lot with this task.



Pulling the radiator support out makes for a FAST drivetrain removal (engine and trans together), and I encourage any endurance racing team to make that happen on their cars. Removing engines is often a necessary task.

DASH GUTTED AND MODIFIED DASH BAR INSTALLED



So the dash bar (above) that came with the Hanksville cage kit was made to go pretty high up and would pretty much preclude the use of the dash. And I really wanted to keep the OEM dash pad, for appearances as well as to make for better "glare protection" and gauge visibility on sunny race days. So it was time to make some changes to the cage. We looked at the OEM dash bar, which has all sorts of integrated bracketry to hold the dash pad.



In March on one of our work nights Tim, Magan and I tackled the dash mockup while Myles was welding on other parts of the cage. We removed the Hanksville dash bar and mocked up an OEM dash in the car (we have two - tan and gray ones). There was going to be interference and notching needed but there wasn't an elegant way to mount the shell.



We removed the dash bar structure from the dash shell and started hacking away at it. To fit it between the two main A-pillar down bars we had to cut the OEM dash bar in half.



We cut the main bar to the right of the steering column support, notched the ends to clear the down bars, and put it into the car. Then tack welded it back together.



This way the dash pad has some of the OEM structure - which is a lot better than how some dash pads get installed. I cannot stand a floppy dash that is bouncing around willy nilly.



Since we compromised the structure of the bolt-in dash bar (we really had to hack up the ends) as well as cut it in half. We built a new straight dash bar to mount just next to the OEM bar. This is going to be hidden under the dash but this one has real structure and ties into the cage in case of a side impact. We will tie the OEM bar to this one, for the structure needed to hold the column. We still need to notch the plastic dash pad to fit around all of this, but I will show that in a future update.

COMPOSITE REPAIR + PROP ROD VS HOOD STRUTS

The composite Seibon hood (24 pounds) is considerably lighter than the stock steel hood (42 pounds), but it is weaker in some ways also. When some of the crew were man handling the hood into place back in March they only had one bolt on one side fastened and somehow with the hood struts installed on that hinge it was tilted, which cracked the mounting flange for the hinges on one side. I've seen similar damage done when using (mostly aftermarket) gas lift hood strut kits.



I was less than thrilled, but "stuff happens" and at least it wasn't a customer's car. Evan extracted the threaded insert plate that had pulled out and sanded the areas to be repaired with more layers of glass and resin.



He cut a space for that into the composite then used fiberglass mat and resin to cover that plate and reinforced the whole area. A little primer and it is as good if not better than new.



We installed the repaired composite hood for a while with one new OEM gas lift strut on one side, but it still felt like the hood was going to fly off when we lifted it up. Just sitting there with the hood up it was bending that side, so we had to do something different. I had an idea...



In late August I installed this S550 Mustang hood prop rod setup. This is an aftermarket, stainless steel version of an OEM prop rod made for 2015-up Mustangs, which was easy enough to install. I added an M6 threaded insert to the radiator support and bolted it on during one of our work nights. Still might tweak this a bit after we get the cold air intake hose and airbox in, but this way we can hold the hood up and NOT have the gas struts trying to bend the hood in half.

PEDAL BOX INSTALL

This car was stripped of the pedal box. We had a loaner for a bit to do some initial mock-up, but we needed to buy our own set of E46 manual transmission pedals and I found this on eBay - the home for junkyard parts.



These bolted in back in late February, but we have not yet installed the throttle pedal. We're using a modified LS3 Corvette Drive By Wire pedal compatible with the Holley Terminator X-Max EFI system we chose.



We have made a lot of these LS3 brackets for various one-off LS swaps in the past, but for the E46 we are going to create a production pedal bracket kit - like we did for our S550 Mustang LS swap (above). We might incorporate the mounting into the Prius steering column center bearing adapter mount, too. More on that soon.

MORE CAGE INSTALLATION

Normally when we take a cage job we can knock it out in a few weeks. Or sometimes it is built in stages over the course of a major build - like when we have to do a lot of wiring or interior work, we want the door bars to go in last, as they are a struggle to work around once in place.



In this case, we're doing the cage work at best for a few hours one night a week, with one fabricator who has a lot going on (Myles). He is also an engineer, CNC operator, and just had his first baby - so he's been pretty busy! Since our last post he has tackled more of the TIG welding and Tim has helped him on a few custom bars (changing the "X" bar we ordered to a NASCAR bar on the passenger side). We did add invest in an air-over-hydraulic kit for our JD2 tubing bender, which makes new tubes easier to make and bends are more accurate.



So the cage is making progress, just slower than we would on a customer's car - because we don't have 8 hours a day or a full time fabricator to tackle the cage work on this "after-hours" employee build.



The main tubes are all in place now and we are just waiting to finish weld in things like the dash bar, an FIA vertical bar we are adding, and one roof bar.

ELECTRIC STEERING COLUMN + SEAT MOUNTING

We have been talking about using an "Electric Power Assist Steering" (EPAS) column in this car since the beginning but I have not shown that yet. Why? because unlike aftermarket supplied units we have used in the past, we're trying to do this with cheaper OEM based column.



The aftermarket EPAS unit above worked well enough in this V8 E46 M3, and I got some good first-hand experience with this on track this January. But it was expensive ($1800-ish) and required a lot of work to join their electric motor to the E46 steering column. It does have a steering force controller on a dial, which is nice, but it wasn't working 100% of the time in our track test. We're chasing issues with that now.



Instead we're trying to make a steering column from a Toyota Prius model retrofit completely into our E46 330 endurance chassis. This could make for a lot less hassle during the install or for replacements later (expect everything to break on an endurance car at some point). We have researched several units and some racers have used the 2004-09 Prius unit (above right). But we have very different height drivers in our car, so the tilt/telescope feature of the 2010-14 Prius might work better for us. We bought both to test with.



Myles has designed and cut out a couple of different brackets that were bolted or tack welded to the BMW steering column mount, to test both the early and late Prius columns. The column was "clocked" so that the motor was not down by our legs this time, as shown above.



To complicate matters the chassis we started with came with no steering column at all - it was pretty stripped - so we didn't have a good gauge of where the steering wheel should be. So we paused the steering column testing for a bit to wrap up the E46 seat bracket base, get the seat installed on a slider as low as possible, then proceed with more Prius steering column mock-ups.



It wasn't until the seat was mounted and the cage largely complete (late April 2020) before we could "test sit" the column. Above is the early tilt version shown at two tilt heights. We could never find the correct Toyota wiring diagrams and pin-outs for the later tilt + telescoping version, so that version will have to wait. We got some schematics, but they were wrong and didn't match the 2011 column we bought.



Tim sourced a Flaming River U-joint that ties into the base of the steering column's intermediate shaft splines and goes to a 1" DD shaft. We then connected the other end to another shaft that will have our BMW 54 spline U-joint at the steering rack. A "center bearing" at the fire wall is needed to keep this multi-piece shaft lined up (a support bearing at the firewall is normal).



We have the center bearing and will fab up a plate to cover the MASSIVE hole in the firewall from removing the OEM bits there. We have since wired in the early Prius column and await getting the car back on the ground to test this further. I made some progress on the custom, bolt-in "filler" panel that will mount the center bearing, which I will show next time.

CHASSIS AND EFI WIRING

Not much to show here yet - just that we ordered and received our Painless chassis harness kit with fuse box as well as the Holley Terminator X-Max harness and computer to run the LS engine.



We will use the Painless harness to replace the missing OEM chassis wiring harness and fuse box, and the Holley system will tie into that to control the engine. Will share more when we have progress to show.

DE-POWERED STEERING RACK

On a work night in late May 2020 Tim started tearing down our E46 steering rack to "de-power" the hydraulic power assisted unit. This will remove some resistance internally and allow the EPAS column to add the power assist, removing high pressure (and flammable) hydraulic power steering fluid from the car.



After we power washed the exterior of the rack, Tim tore it down like he would any Miata rack - which he has de-powered many times. The pinion was removed, then the rack portion. On the horizontal shaft in the rack, the separating piston was removed.



This is what allows for the assist - as hydraulic fluid pushes on the piston left or right. With that piston removed - viola! - it is de-powered. He re-assembled the entire unit with grease (the pics above, shown out of order) and then got it ready to go back into the car with new tie rods and boots.



HPR 6.3L "STOLEN" + REFRESHED 5.3L LS V8

I showed the Horsepower Research 6.3L cathedral port LS engine build slated for our endurance car here in a previous installation. That was completed during the 'rona, but I stole it for use in my LS550 swap development, shown below. That project car is on the final stretch and we needed a ~500 whp engine to get this going for Phase 1 of that build.



This 6.3L LS6 will be used for initial testing on the Mustang then it will go to it's true home - our Endurance E46 here. In April we took our "backup" engine and rebuilt that, also at HPR. I horse traded for an aluminum 5.3L truck LS engine and it has similar cathedral port heads, just with a smaller displacement.



Turns our this engine was pretty worn out - pistons, rings, and bearings were worn but not overly damaged. The pistons were replaced, as were the rings, bearings, and more. Didn't need an overbore, just a "kiss" of the hone, some bearing setup, a spicier camshaft / valve springs / retainers / locks, new roller lifters, custom pushrods, and reassembly. The worked happened during the biggest parts shortage period during the pandemic and HPR got this done unusually quickly, since it needed so few parts. It was done in late May and we didn't get it fully assembled and into the car until June.

NEW FRONT LCAs, WHITELINE BUSHINGS, & TIE RODS

With as many sphericals as we have on this chassis, normally you'd think we would go right to a spherical Lower Control Arm bushing at the factory "lollipop". In the past we have used Powerflex 3-piece LCA bushings, which have to re-use the OEM lollipop casting. On this car I wanted to do some long term testing with the Whiteline W52519 LCA bushing and housing kit. It comes with the same 3-piece (rotating) urethane bushings with new lollipop castings.



We installed these with new non-M E46 Lower Control Arms, which have new ball joints in both locations. This will all be a test to see how the OEM style arms and poly bushings work out on the endurance car. A one-piece poly bushing would be a BAD choice here, but with a 2-piece bushing it allows for proper articulation.



Long term we might have some fancy doo-dad tubular arms with spherical ends - but the costs go up by a factor of at least 5 over what we have here. Having driven E46 cars with "magical" tubular arms and geometry fixes it didn't seem life changing as some claim.



Again, it is something we can likely test down the road to see IF IT MAKES THE CAR FASTER. If it does, we will do it. If it has drawbacks (like cost, reliability, etc) we will fall back to this setup.

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[Fair!]

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New inner/outer tie rods went on along with the de-powered steering rack, new Lower Control Arms, and the LCA bushings from Whiteline.

REAR SUBFRAME MOUNT & RTAB REINFORCEMENT

Like all BMW E46 chassis, the rear subframe mounting points on the tub need reinforcement, so that was a big task I saved for the new guy, who was a welder for use for a number of months. We do these jobs periodically for customers and I like to break in a new tech on a shop car instead of on a customer's car.



In the last week of May 2020 we made room on the lift for a couple of days to tackle this work on the clock. Brad and Evan showed the new guy how to do it and helped remove the fuel tank and rear subframe.




After the chassis was cleaned of paint and undercoating (the least fun part of this job) the CSM reinforcements were bolted into place and it was time to TIG.



The 6 plates were TIG welded, seam sealed, primed and painted within a couple of days. While the OEM fuel tank was out I went and power washed that to look as good as new.





One of the areas on the chassis I have personally seen fail (at least on the E36 chassis) is at the RTAB cassette mount. So I asked Myles to make a tracing of the OEM mounting holes and shape, design a CAD drawing, then cut a pair of reinforcements. With one small tweak we had a new product, and we are using our chassis to test it out on. Which is part of the reason why we're building this car.



With the RTAB reinforcement welded in, seam sealed, primed and painted it was finally time to install the upgraded, powder coated, and stronger E46 M3 rear subframe and diff. This move let's us go from an open 188mm diff to a limited slip 210mm M3 diff.

REAR M3 SUBFRAME WORK

As you loyal readers know, we're upgrading our E46 330Ci to use an E46 M3 rear subframe - brake to brake. Gives us the stronger 210mm LSD diff housing, stronger M3 trailing arms, beefier M3 hubs/axles, and bigger M3 rear brakes. We finally had the rear subframe assembly reinforced subframe, bushings installed, and new sealed sphericals installed - so this was a complete weight for the unit, without axles. 222 pounds of aluminum and steel.



A big hunk of that 222 pounds is the diff (95.4 pounds), another big chunk are the steel trailing arms (68.6 pounds).



There were several upgrades done along the way to get this rear M3 subframe assembly read for endurance racing - and I'm sure we'll see something else in track testing. We have shown the subframe blasted, seam welded, reinforced, and powder coated in previous forum thread posts.



This assembly went into the car with SPL Parts spherical rear camber links, shown above. This is a part we have used on a number of BMW builds and we know the guys at SPL very well.



This all went into the reinforced chassis without any issues, lined up and bolted up. It was time to put it on the ground and see how it looked...

M3 REAR TRAILING ARMS: BENT, RUSTED, BROKEN, & GOOD!

It didn't take long to see the issue with our first of FOUR different left rear trailing arms - it was bent (see right vs left pics below). This arm was from a rear subframe I had purchased along with a car more than a year previous, so it was too late to cry sour grapes.



With the naked eye you couldn't see any wrinkle or bend in the hollow cast steel arm - it wasn't until we had a replacement arm next to this one that the bend was obvious. Not a part you try to "fix", either. That bent arm is scrap at this point.



Luckily I had another E46 M3 rear subframe assembly I had bought in late 2019, so that arm was pulled for use on the team car. But the bad luck just kept coming. As the rear wheel hubs were being removed for a rear wheel bearing replacement, it just broke. Yes, we know how to do this job and have done it many times... it was a somewhat rusty arm, so that didn't make it far. Wasted probably 2 hours on this one before we got to this point.



So I bought another E46 M3 trailing arm, and this one *came with the axle. It also came with a single Ground Control spherical RTAB, which Tim removed - we're trying to test the Sealed Spherical we had installed on the previous bent trailing arm. (*NOTE - if it comes with the axle it is because they couldn't get it off!)



Tim and Magan fought with this 3rd trailing arm on the bench - the axle didn't want to come out. They got the upper and lower sphericals replaced and the sealed spherical RTAB, and I told them to put it on the car and we could use a slide hammer and heat on the axle...



Once on the car a couple of weeks later (remember: we're only working on this one night a week for a few hours, at best) they tried heat, slide hammers, but that axle will NOT come out of the hub. The end was ruined before it got to us (at the junkyard that sold it to me). I've since learned of a trick to get this out - soaking the axle in some "magic sauce" (50/50 mix of Acetone and ATF fluid), which we will do later to salvage this trailing arm.



But at the time I was getting sick of this damn trailing arm holding up the build and burning up hours - the bearings and RTABs were moved to each arm, the brake backing plate modified each time, etc. So I kept "throwing money at the problem", and bought bigger tools and more trailing arms until we had a setup that worked.



Forth time's the charm! This was the best looking used trailing arm so far, and one night Tim got that one swapped to the new bushings, RTAB, hub removed, and on the car. Then he and I got the snap ring extracted, then the wheel bearing pulled.



Next up the arm comes off the car, the new wheel bearing gets pressed in, then the snap ring, then the hub is pressed in, then it goes on the car, then it gets the new axle for that side. THEN the car can go on the ground and get ride heights set. Whew! That whole process was some nonsense, but we should get at least 2 spare hubs and a full spare trailing arm assembly out of the spare parts, once we soak arm #3 with the "magic sauce" and get that rusty axle out.

SPHERICAL BUSHINGS

On the upper arms there are rubber bushings on the inboard side. Rubber bushings are the Devil - they allow lots of deflection under lateral and braking loads, which we don't want. So we invested in these Rogue Engineering spherical bushed housings for this location, shown below left.



Tim used some sockets and the 20 ton press to push out the old rubber bushings and housings, then used an old mechanic's trick - tossed the Rogue spherical housings in the freezer for a few hours.



That shrinks up the bushing and allows it to slide into place in the upper control arms nicely.



The Rogue housings have a face on one end that you press to the control arm. The other end has a groove for a snap ring, which secures into the arm. Inside this housing is the spherical bearing, with bushings that press inside that to allow the bolt to fit and provide articulation. Above right is this end of the re-bushed upper arm bolted into the E46 M3 subframe.



The trailing arm has two sealed spherical bearings from the factory - and we replaced the old units. On. All. Four. Trailing. Arms. Getting the old units out was relatively easy using a BMW specific press and cup tool set we have.



Pressing in the new units is pretty easy - they just press in with the same tools. Those shouldn't be a problem for a long time on the final arm that went into the E46. They don't wear as quickly as "open" spherical bearings do, which some racers like to use. We try to use sealed sphericals whenever possible - the rubber seal keeps rain and road grit from destroying the metal ball and surface of the spherical, just as the factory intended.

WHAT'S NEXT?

There is a LOT more work completed, but the "write-up" was taking too long and so I cut it short here. Next time I will show the 18x11" wheels, rear unibody and front fender cutting / clearance work for the Clinched flares, and the "real" 5.3L LS V8 and drivetrain install.



Sway bars, and the ensuring drama that a new brand brought with it. The rolled radiator mounting, steering wheel / hub / quick release, replacing missing things like door latches and handles, and more.

Thanks for reading!

Terry @ Vorshlag

[Fair!]

Project update for February 23, 2021: It has been 5 months since my last post in this thread, and as usual, a number of of things did not go according to plan (because our endurance E46 still isn't done!) We had more turnover in one position but we found a solid replacement in Zach, who's been here for months now. We had a couple of Covid scares where we all got tested, and one person in the shop actually got sick, but has since recovered. Then we had the craziest winter storm to ever hit the state of Texas in mid February and lost power for 3 days at the shop last week, shutting us down completely.



Of course we are all frustrated that we haven't finished this E46 yet, but the shop is slammed with customer car work, plus one of our technicians is also manning the fab bench - and orders for those types of parts have ramped up even harder. We're still mostly working on the endurance car one night a week, but I have snuck in a few days of shop time here and there - and I'm about to ramp that up more to speed things up.



There is a lot more work completed since the September 2020 "write-up", and I only got through June 2020 on that one, so I will tackle the last 8 months of work on the E46 endurance car this time. It is going to be a big one, so let's get started.

MYSTERY TRANSMISSION REVEALED: TREMEC TKX

One of the things I couldn't talk about until November of 2020 (due to an NDA) was the exact transmission we were using in this car and the '67 Mustang LS7 build. We got a pair of pre-production Tremec TKX 5 speed transmissions for these two builds, to test for track abuse, street use, and drag racing duty (on the '67).



There is a lot of information about this all new, modern 5-speed transmission design here, but the basics are: it is a 96 pound box with multi-piece synchros, carbon blocker rings, 3 ratio options, and a 600 ft-lbs rating. This is not based on any existing transmission (like the TKO it replaces) but a modern, clean slate design. It fits in classic Detroit iron but we have made kits to fit this into several of our BMW LS swaps, too.



We used our E46 endurance coupe build to develop the transmission crossmember and driveshaft solution for the E46 solution, and we put this into an E36 LS swap chassis we have on hand to develop that crossmember and driveshaft also. Running this in 8/12/24 hour races in our E46 should be a good test of this new box! More development on other chassis will come as time permits.

5.3 LS ENGINE - FULLY ASSEMBLED

We got the refreshed 5.3L LS engine back from HPR in late May 2020, and one of the things they noted when installing the Summit Racing oil pan was something we had to fix. The oil pump pick-up tube that comes with this pad was extended by almost .300" and the oil passages thru the pan were "ported". We describe the what, why, and how of all of this in this post.



Evan was still with us then and I had him assemble all of the parts and pieces to this 5.3L during shop time. He installed and fixed the oil pan, the ICT billet valley cover p/n 551272 (necessary as part of our "Displacement On Demand" delete for this Gen IV LS aluminum engine), installed the SFI balancer, valve covers, and more.



With the balancer installed (using an LS7 "long snout" bolt, then once pulled in place, using a normal "short snout" ARP bolt), he then cleaned up and installed the truck ignition coils and brackets. We used the long LS7 bolt to start the pulley as it engages more threads before it starts pulling. Then it was time to tackle the steam vents...



The normal "car" LS engines use a 2-port steam vent crossover tube at the front of the block and a couple of block off plates in the ports at the back of the heads. We talked to HPR and they recommended a 4-port vent kit for use on this endurance car, so Evan modified a 4-port OEM truck steam vent to fit with our LS2 Dorman intake.



It took a bit of work but he managed to make it fit, which saved us $100-200 for an aftermarket 4-port steam vent kit made with AN lines. We'll see how well it works. The intake was just mocked up above, as we needed to remove this during the drivetrain installation.

REAR SUSPENSION WORK COMPLETED

In the last installment we covered the removal and replacement of all manner of bushings, bearings, arms, and sphericals in the rear suspension. The bent E46 M3 trailing arm stalled us out for a bit, due to a rusted and seized replacement. But the third arm we bought was good, and that went into the rear subframe assembly with new bushings and RTAB spherical.



I asked our crew to put this finished E46 M3 rear assembly on the scales to get a weight on this unwieldy beast. 222 pounds was about what I expected, and similar to what a solid axle weighs if you think about it. But the advantages of beneficial rear camber and toe curves, and adjustable rear camber and toe settings, outweigh any possible weight savings of some dang solid axle!



That's a bit heavy to lift by hand, but with the assembly lifted in place via our transmission jacks, we were able to get everything bolted into the chassis and attached the MCS RR3 triple adjustable rear dampers.



The horsepower and torque we will be allowed to make in WRL GTO class is pretty low - around 300-330 whp, depending on our final weight - so we didn't spring for 1000 hp ($1000) axles. Instead we bought some cheap, new, OEM replacements for the E46 M3. These should be more than capable for the power output we are allowed.



I'm glad we went with affordable axles because of all of the issues we had with trailing arm problems - one of the new axle stubs got stuck in the outer wheel hub flange and we had to just pull it out and replace the whole corner. We had some really bad luck in buying trailing arms, that's for sure. If you ever see one for sale with an axle attached - run away. It means they couldn't get it out and its stuck forever!

FLYWHEEL, CLUTCH AND HYDRAULICS

The power this 5.3L should make will not stress even an OEM LS clutch setup, but we wanted to get something a little stronger. We looked at a couple of brands but this Stage 1 ACT organic should be easy to drive and more than strong enough.



We didn't want to add the complexity of driving an unsprung or puck style metal clutch to the mix, or something super light (which means expensive). This should last for years if it isn't painfully abused. Of course I weight it..



This clutch is made for use with an LS2/LS3/LS7 flywheel (but not the GTO version). I happened to have a Fidanza aluminum flywheel leftover from our LS6 engine in the original Alpha E36 LS1 build from way back when. This was cleaned up, the surface scuffed, and bolted to the crank with new ARP hardware.



Now it was time for the clutch hydraulics. This Tremec TKX is setup with a 26 spline input shaft and a length similar to the old TKO. So we went with what we knew worked on those from previous use, a Ram HD hydraulic clutch slave cylinder kit. The RAM HD kit comes with the slave/TOB, a shim kit, a mounting stud to align on, a length of hydraulic line, and a bleeder for use right on the slave.



Bleeding a clutch this way is nearly impossible. Instead we spec'd out a hydraulic feed line from the BMW clutch master cylinder to the RAM slave, then added a remote bleeder line as well. We had these built and added them to the slave.



If the E46 LS TKX kits start to sell, we will offer all of this as a turn-key kit, with the hose that plugs right into the BMW master. Makes it super easy to do the install this way, in one step instead of a couple of test fits and trips to the hydraulic hose store.



The Tremec TKX shares the bellhousing pattern with the TKO, so we used one of these bellhousings we sell. It is a beautiful cast aluminum and machined part and we have sold a number of these when we supplied TKOs to customers before.



We aligned and installed the clutch and pressure plate, then the bellhousing was mounted up. To verify that everything fit we also installed the starter... and had an issue.



With the bellhousing removed the interference with the nose of the LS starter was marked where it fouled. A few minutes with a carbide cutter on the die grinder and a couple of test fits later, it was all fitting nicely. Just something you might want to look for on these bellhousings when using the LS style starter.

REAR SWAYBAR

Normally we would go straight to Whiteline for our swaybar needs - and have used them on previous E46 builds, like our TTD/TT4 330Ci below. But their support for the BMW E46 chassis is less than complete. They make an adjustable 30mm front bar for the E46 M3, but when we went to order it they showed to be out of stock for months (and we actually have a non-M E46 front subframe/uprights anyway). The Whiteline non-M E46 front bar isn't adjustable, so that was less desirable. Whiteline doesn't make an E46 M3 rear bar at all, just the non-M. Which won't fit the E46 M3 diff (as we show below).



So we looked around for another option, hopefully with the same brand of bar front and rear, with our unusual E46 non-M front and E46 M3 rear configuration. We also wanted some adjustments at both ends. Hotchkis had what we needed - they are stepping into the swaybar market with new offerings.



We installed a Hotchkis swaybar kit on another car recently and were impressed with the quality. They make both E46 non-M and E46 M3 versions for both the front and rear, which are different. So we ordered the non-M front and M3 rear, to match our subframes and suspension parts.



Now the first set of bars we got from them was ordered as a non-M E46 front and M3 rear, but they had mislabeled a whole batch of boxes and we got a non-M rear, which fouled with the M3's finned rear cover - this shouldn't fit like this - as shown above.



We had to take some pictures of OEM swaybars to convince them, and had to wait a good bit to get the right M3 rear swaybar, but it eventually showed up. Again, Hotchkis is fairly new to the German car swaybar segment, but its a nice piece.



I missed the work when they installed the "straight" E46 M3 rear bar, so I took it while writing this in February 2020 - and the rear shocks were removed, due to some rear shock tower welding. So this droop level is NEVER something you should ever see in an E46 rear suspension, as the shocks act as a droop limiter.

FUEL RAIL AND INJECTORS

We could have chased down some used LS2 factory fuel rails to fit our Dorman LS2 / 90mm intake manifold (615-901) but I wanted a full "return style" fuel system, with a feed line to the engine bay and return line back to the fuel tank (or in our case, the remote fuel surge tank, which I will show in another installment).



We commonly use FAST or Holley fuel rails for most of our swaps, and went with the lower cost Holley "Sniper" rails for this install but, the crossover hose was too long...



Evan shortened the long hose (above left) on the Holley 850001 kit and made it fit our LS2 intake and injectors. This will be fed via the Holley HP Billet Fuel Pressure Regulator 12-846.



An ACDelco 90mm drive-by-wire replacement LS3/LS7 throttle body (12605109) was bolted to the manifold. We spaced the later "short" injectors with the FAST Fuel Injector spacer kit (146025-KIT), and had the OEM Gen IV 5.3L injectors cleaned and flowed at InjectorRx in Houston. Lots of sensors and grommets were installed on the intake manifold, too. This assembly would be installed after the engine and trans were in the car, to make room for the engine hoist / chains.

FINAL DRIVETRAIN INSTALL

With the refreshed 5.3L engine now assembled and ready to go into the car, and the clutch/bellhousing installed, the TKX transmission was bolted to the engine (I didn't get pics of this step). On June 18th, 2020, Tim, Evan and Magan installed the engine and trans as a unit.



We were able to use the engine leveler and just stuffed the whole thing in from the front, with the radiator support and bumper beam removed. Magan was using a floor jack to line up the transmission and keep it from dragging while Tim and Evan lined up the engine mounts.



Takes a bit of adjustment (there are slightly oversized holes in the engine mounts to allow for this) but it fits in there perfectly. The newly powder coated E46 TKX crossmember bolted in place to hold the transmission in.



Normally we build an E46 with the Tremec T56 Magnum or the slightly longer (1.5") T56 Magnum F - which is the new size that mimics the 1998-2002 F-body T56 (Camaro/Firebird) length with the upgraded magnum case and guts (700 ft-lb rated). Those have shifter distances that line up with the E46 shifter hole, but they are heavier and more costly. We didn't have either of those lying around, but we did have the 5.5" longer T56 Magnum XL on hand, which we use in S197, S550 and 86/BRZ swaps. As you can see above the TKX much shorter than that. It even has a "bellhousing to shifter" interface is about 2" shorter than the T56 Magnum.



Not a huge deal, and as you can see above and below the TKX shifter hole is about 2" forward of the factory E46 shifter hole. It might complicate a street car's interior, but for a race car, this lighter and less costly 600 ft-lb rated TKX is still a great choice.


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Here are some pics of the shifter hole that was opened up to fit the Tremec TKX shifter placement - admittedly they went a little too far forward on the cuts - this will all be covered by some aluminum sheet metal and hidden under a Joe's Racing shift boot. The second pic above shows this with the stock dash in place, and a shifter handle we mocked up. We will build and offer one to fit around the stock dash section here, which we plan to keep in place.

FORGESTAR F14 SUPERDEEP 18X11 WHEELS

We had a set of gold 17x10" Forgestar F14 wheels on this E46 coupe for the initial part of the build simply because they were on hand. I bought these as a second set for my red TTD/TT4 330Ci. When the buyer of that car picked up car, he chose only the silver 17x10s and decided not to buy these gold spares.



These 17x10" wheels don't really fit the non-M E46 fenders, and we ran the HARD Motorsport flares above to clear the wider-than-usual "245" Hoosiers. We can't use Hoosiers in endurance racing, of course, and had always planned on a wider 18x11" wheel and much wider 315/30/18 200TW tire.



We have been a dealer for Forgestar since 2012 and have sold many hundreds of sets of wheels. Many things have changed with this company, including ownership - multiple times. Weld bought Forgestar, then MOMO bought weld, and MW Wheels was the end result. We quickly realized they were no longer interested in making these custom offsets and patterns we needed - they added a heinously high "bespoke" wheel charge in 2020. When the 18x11" wheels we spec'd and ordered for our E46 arrived in late April 2020, and they had built them for the wrong bolt pattern, we were not shocked.



It was easy to see before we had mounted tires, as we always "test fit" wheels to the chassis before we throw tires on. Not what we wanted to see, but "stuff happens". We re-ordered the 18x11's with the same PO but emphasizing the information on the original PO with the 5x120mm bolt BMW pattern. The 5x4.5" pattern they were built with accidentally fit another car in our shop, the '67 Mustang above left. So we got "lucky", other than losing months for the correct spec to be built.



The correctly made wheels arrived in July, so we triple-checked everything. Then I took the wheels to mount up a set of 315/30/18 Rival-S tires. Always test fit custom wheels to your car before mounting tires! The used 315mm Rivals are from my wife's FR-S and will work for initial "driving around", dyno work, and first-fire testing. A fresh set of new 315mm tires will be installed before we attempt any laps on track, as these tires are pretty old now. What tires will we buy? Stick around and find out.



We added a hair more room to the rear to be able to clear the coilover rear shock setup, so this is only a bit more "poke" you would see on a non-M E46 with 315mm tires on 18x11" wheels.



We did some initial testing on the front and back, checking steering clearance at lock (it will need some trimming), and then got busy on other aspects. Will it need a flare? Of course, it will need BIG flares at both ends.

FENDER CLEARANCE FOR 315MM TIRES

A week later, mid-July 2020, we got to work trimming the fenders to fit these fat 315mm tires on the 18x11" wheels. It was clear (below) that we had some serious poke to cover up and I had purchased some Clinched universal "Euro" flares for initial test fitting.



After removing a spring on the front strut, Tim and Magan took the front suspension to "full bump" and of course the 315mm tire was crashing into the fender lips long before the damper ran out of stroke. The 2" of tire poke would easily be covered up by the flares we had (above right), but they would require a considerable amount of trimming.



Tim marked then hacked away the offending fender lips on the front using an air body saw and the "spinny wheel of death". These initial cuts look pretty nasty, but all of this is hidden under the flares and we will clean up the edges. But with this clearance the tires could go to full bump travel, where the tire would be running into the inner fender along an arc and not slicing into a sharp fender lip.



The rear fender clearancing and cutting is a LOT more work than the front of any unibody car, and as such I had Evan do this one on the clock. He has flared a few cars while working here and knows all of my tricks, and then some. He marked the outer skin at the line where the inner fender starts to curve down and chopped that off..



Then he cut the inner fender lip at the same height. This leaves an inner fender gap but the inner structure no longer curves down to meet the outer lip. He cleaned up these two sections of sheet metal for the next step - bridging the gap with some steel sheet.



We keep 18 gauge carbon steel on hand for making these patch panels when flaring cars and Evan got to work cutting a strip about 3" wide that would arc around the curve of the fender opening and overlap both sections. He then tack welded these in place to the inner and outer sheet metal, which had been cleaned of paint and undercoating. The insides of these sheets still have stuff on them that cannot be cleaned, so this welding causes small fires on the interior. A person sitting inside the car with a squirt gun can shoot a little water at these flare ups and they go right out.



Above you can see this 3" strip of steel sheet being tacked to the outer edges of the outer fender metal. These cover the gap and overlap the inner fender structure - to tie it all together. This stuff is a bear to weld due to the crap on the insides you cannot get off, so a series of skip welds are done. Tack, move an inch, tack, move an inch, and repeat until you have a fully welded seam. This adds the structure back to the unibody tub that you cut away and leaves a flat inner fender section for maximum suspension and tire clearance.



With the stitch welding wrapped up the outer portion that protrudes past the outer fender skin is trimmed off and the weld is dressed with a flap wheel. The shots above show the inner fender patch panel after it was fully stitch welded, then seam sealer was applied, then zinc-based metal etching primer was applied inside and out. Leave any of this raw steel and it will rust, so get the inside too. The seam sealer makes it all water tight so nothing gets inside the cabin, too.



Obviously this shot above still looks pretty crude but 90% of the heavy lifting has been done. Adding the actual flares is the easy part. Well, normally. These flares are "universal fit" and we want to add some extra venting on the back sides for less drag, so we will have to do a lot of fitting on those - which comes later.

STEERING WHEEL AND QUICK RELEASE

For a long time we had the stock Prius steering wheel in the car, but it was hideous and huge. In April 2020 we started measuring the splines and looking for a bolt-on adapter for use with a 6 bolt / 70mm PCD aftermarket steering wheel. After a lot of searching and some questions sent to Sparco we finally found the right hub adapter.



By August 2020 the Prius steering hub finally arrived - yes, it 4 months it took to get from Sparco. Not a hugely popular car to prep, it seems. One thing we had settled on was the Lifeline/Sparco quick release hub, which we have on almost every single car in the shop. This was a sponsored part given to us one of Tim's race team owner buddies.



We happened to have a Model 88 MOMO wheel in stock, which we took as a return from a customer - so one more "leftover" piece made it's way into this build, for now.



This wheel is actually pretty small in diameter (320mm/12.5"), and that makes for a faster steering action - which is more suited for an autocross car. This Model 88 also comes in a 350 mm diameter, which is more suited to an endurance road race car.



In January 2021 we had a new seat in place (after 2 additional seat changes - see below) and tested with 3 different size steering wheels from other cars in the shop with the same Lifeline/Sparco QR. The 350mm diameter is actually better suited for the new seat & steering column, and gives us both a slower steering response (good) and more visibility for the digital dash that is coming.

VARIOUS SEATS FITTED

Hang on because this is a bit of musical chairs. Back in April 2020 we had developed an early version of an E46 seat bracket base, then fitted this Sparco EVO III, which is a very wide seat. We did this to fit one or two big drivers on the crew, but they have since lost a LOT of weight, so I was wanting to fit something better. I had a customer who needed this EVO III and sold it, knowing we'd use something else from our inventory.



By October 2020 it was time to look at a better, safer seat design. I had an extra OMP RS-PT "halo" style seat on hand from our old lobby seat displays and it was still within the FIA 5 year window, so we all "test sat" in that and got to work on a better seat install.



Myles had also finished welding in the strengthening ribs on the prototype E46 seat base and we had it powder coated, so Tim and Magan worked on the slider and seat side bracket install for the OMP.



Well that OMP was needed for yet another customer emergency, so we pulled it out and happened upon my all time favorite seat - the Sparco Circuit II. This is the wider version of the halo style Circuit seat, and it actually came out of my old red 330! In November while at the Optima World Championship Autocross (above right) at COTA, I traded an EVO II US for this Circuit II, and we got to work installing seat # 3 on the endurance E46!



This went in with the same Sparco sliders, and yes, we will have to add a seat back brace for use with those in W2W racing. The sizes of our drivers is diverse, but we all fit in this seat. The Circuit II works well with long torsos for tall peeps like Tim and I, but also works on drivers that are more compact. Since this is my favorite seat I am going to hang onto this one and make sure we don't install seat #4!

WATER PUMP & ALTERNATOR INSTALLED

There are a number of options when it comes to factory Gen III and Gen IV LS serpentine belt and engine accessory arrangements we can choose. We tend to stick with two of the most compact options: the 1998-2002 "F-body" and the 2004-07 CTS-V/G8 setups. We decided to go CTS-V so in August 2020 we purchased Gen I CTS-V alternator and brackets for use with out E46 LS build. We like the compact fore-aft pulley placement of the C5/C6 Corvette and CTS-V/GTO/G8, and the C6 LS7 Corvette water pumps can work too.



We chose the later (2009-13) Corvette C6 Z06 / LS7 water pump for our build here, as it puts the output port on the driver's side (see above left). Alternately we could have chosen the early C6 LS7 (2006-200 water pump (see below left), which has the pump outlet on the passenger's side of the engine bay. We pick one or the other depending on how we have the radiator inlet/outlet arranged.



On this S550 Mustang LS swap above we are using a Howe double-pass radiator with its inlet and outlet both on the passenger side, so the upper hose can have a shorter run with the early C6 LS7 pump, as shown.



Our E46 is using a "single pass" custom Griffin radiator with the top inlet on the radiator on the driver's side and the bottom outlet on the passenger side, so we chose the late LS7 water pump. We will show more of this in the radiator mounting section, below.



The alternator is a 150 amp unit from a 2004-07 Cadillac CTS-V. We like this packaging the best - the CTS-V alternator is mounted tight and low to the block with a unique, extra mounting arm cast into the unit. This allows for another bolt to attach to the engine block on the back side.



The belt arrangement from the CTS-V can also be modified to work well for use without a power steering pump, which is what we will run since we have the EPAS electric steering column, as well as on the 86 swap (above) and LS550 swap, both of which have an electric EPAS steering rack.

DASH SKIN FITTED

This is an old pet peeve of mine - gutted race cars without a dash cover. Why does it matter? Two reasons - the cage's dash bar and an ugly mess of wires reflect up into the windshield and make a lot of glare. Second, it looks too low end, and this car needs to reflect well on Vorshlag, even if we have some leftover parts being used.



Back in June 2020, the arguments over "using a dash or not" were played out and this tan dash skin was test fit into the car. This dash pad came out of another car and whoever removed it cut some part of the left side away. Not what I wanted but we needed to trim that side anyway, and we can patch that over and make it look good. We will also paint the tan sections black, and might even flock the whole thing.



The dash still needed to be fitted, as it wouldn't slide forward due to the roll cage tubes in the way (see above left). So in late October I asked Brad to tackle this during shop hours. His detail oriented work made this look easy, and he had the dash trimmed and fitted in a relatively short amount of time.



At this point we still had the OEM dash bar and brackets in place as well as our roll cage dash bar. This double dash bar setup would get pared down later, when the steering column mount was tackled. The dash skin still fits and will make a good place to mount switch panels, the digital dash, etc.

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MORE ROLL CAGE WORK

The E46 cage kit we bought from Hanksville has been tweaked, changed, fitted, added to, and welded in place. All of the work has been after hours and it is 90% done. Normally a cage takes a couple of weeks, but doing it in 2 hour bursts once a week definitely drags things out, and it is easy to lose where you were the week before.



Myles has done most of the welding on the cage on work nights when he could make it, which were a bit scarce for a bit with a new baby at home. But the main cage parts are completed and both door bar sections were in place. The kit originally had an "X" on the passenger door but we changed that to the ladder style NASCAR tubing. As you can see in the pic above left, we are extending the verticals downward to the stock rocker structure - with load spreader pads. This makes the cage door structure REALLY strong, and more than makes up for any small weakness added with the "S" curve.



Our newest fabricator / technician / engineer is Zach (above right), who worked with Myles in FSAE years earlier. He joined us in November of last year. He has been here for all team car work nights since and has helped with some of the cage tube fitting and TIG welding. We added the FIA vertical tubes to the kit (see above left), like we always do.



Zach has jumped in with both feet on the team car, to both show his fab skills as well as to get a spot on the team - so he can drive this car! He has fitted the optional FIA bars and started on the optional roof bars.



Zach and Myles worked on the roof bar and the main hoop diagonal. Next was the upgrade from single foot protection bars to the triangular tubes we wanted...



Zach made this structure above on the fab bench to be able to cut / cop / TIG weld these tubes together. This trick allowed him to weld the junction and "foot" to the end of the triangle, then he only had to stand on his head to weld the two legs to the main down bar and the foot to the floor.



Smaller diameter tubing was also cut and coped for some triangulation at the top of the cage. These also work REALLY well as a grab handle when getting into and out of the car.



We are close to wrapping up this task, and I will show more of the cage work as the last few tubes are welded in.

RADIATOR SELECTION AND ROLLED MOUNT

Cooling for an endurance car is not something you can minimize. When we began working on this car we had a leftover Mishimoto drop-in unit we could have used, but that is setup for BMW's stupid "quick connect" radiator hoses - which are a huge PITA. Instead, we wanted to use a bigger, custom sized, rolled radiator on this endurance car. This could gain some room for an air filter over the top of the radiator. So when it came time to buy a radiator support (this car had none - see last time) we cut away the center bits to make room for the roll. We also designed the curved, tubular bumper beam to push as far forward as possible, to give us the most room for the radiator.



After taking some measurements, Jason and I dove into the catalogs of Howe and Griffin for a universal fit radiators that maximized our room. These are two U.S. brands that make aluminum radiators for circle track, and the costs are always low, but you have to spend a bit of fab time making mounts. We ended up buying this Griffin 1-25182-XS, which is an all Aluminum unit that is 22 inches wide, 19 inches tall, and 3 inches thick. This is a "single pass" radiator with the upper inlet on the driver's side and the lower outlet on the passenger's side (which is why we went with the LS7 water pump config we described earlier).



The Griffin radiator was made to order and took a few weeks to get here. It arrived by early June, and we wrapped the core in corrugated cardboard to keep the fins from getting smashed during construction. We didn't have the drivetrain back in the car until late June, and eventually started the radiator install in late September. The mockup began by sitting the bottom tanks on some jack stands and we tested several different angles. With the core support trimmed away laterally we could roll this core as far as we wanted.



By late October we got back to this and Tim made some valid points about not having the leading edge of the radiator almost touching the bumper cover (a light impact would destroy the core and put us out of the race), so the angle of the roll was reduced from close to 45 down to the final 39.3 degrees. We also cut off the radiator fill neck, which would be plated over. The coolant fill would happen from a remote reservoir.



Myles designed some upper radiator brackets in early November and cut them on the CNC plasma table. Zach was with us full time by then, and he machined the aluminum pins for the upper mounts to fit inside grommets for these brackets, plus capped off the old filler neck hole.



Later in November the "ground plane" for any potential flat bottom body panels was checked, to make sure we hadn't dropped the radiator too low - it was still 1.5" above that, so we were good to go on the bottom mounts. Somewhere in this month the lower fiberglass headlight trim I ordered arrived, too.



Now we are in December and Zach and Myles teamed up to make this lower radiator support. They CNC cut some flat 18 ga steel sheet, then bent it in the box brake, then added dimple dies to the lightening holes.



The uprights welded to the lower part and two nutserts were added to the frame rail to mount it, as shown above. This let the radiator sit in the lower portion that is parallel with the angle of the roll. Two rubber bushings went into two of the holes with more aluminum pins welded into the end tanks for positive location and isolation.



They painted the cradle black and the upper mounting brackets were bolted to the modified radiator support. Several inches separate the radiator core and the bumper beam + sheet metal bumper cover bracket, as shown above right. Four isolated pin mounts secure the rolled radiator and there's still room above it for an air filter, which I will show later.

DOOR LATCH & OTHER SMALL DETAIL ITEMS

This coupe chassis was stripped of literally anything of value when we got it, so we had to go chase down a number of silly missing items like door handles, latches, and the like. Don't start with a complete rag of a chassis and you won't get bogged down in this little stuff like we did.



We ordered an inner door latch for the driver's door, an outer door handle, and an inner door release from various sources. This is about the only thing eBay is good for in the car world - finding used OEM parts from junkyards.



We kept enough of the door structure to attach the latch, and on the driver's side we kept the upper structure - as it helps during driver changes, in case somebody leans on the door. The passenger side is stripped of much of this upper / inner structure. Well it made it easy to add the inner latches, which were found on RockAuto.



The carbon hood has no latches at the moment but we found the adjustable "hood bumpers" and ordered those, which thread into the upper radiator support. This helps cushion the closing of the hood and helps set the hood height.

WEIGHT CHECK - OCT 2, 2020

This "weight check" on October 2nd gives us some idea of where we are with respect to weight. Of course when I post these pics on social media, people lose their ever lovin' minds and "can't understand why you post incomplete weights!!!!" Goodness, people, just calm yourselves. Why did this clearly incomplete weight data hurt you? We post a lot of weights throughout every build, and of course we will post the final race weight when the time comes, too.



This weight has the entire drivetrain and suspension in place and complete, 95% of the cage completed, the big front brakes, the EVO III seat, the 18x11" wheels, radiator, full sized Optima battery, and more. We have none of the glass in place (2-layer safety windshield and Lexan rear), the sunroof panel wasn't in yet, none of the auxiliary coolers, and no fluids. At worst we might gain 200 pounds? So we might need to add ballast, otherwise we will be really capped on power with WRL GTO's 9:1 pounds per whp limit (and that weight is without driver).

DRIVESHAFT DESIGNED, BUILT & INSTALLED

In October we received our first E46 / TKX / 210mm diff driveshaft. This is a 3" diameter aluminum unit with a slip yoke at the front, which we can configure for T56, T56 Magnum, or now the TKX. The back can be configured for E46 non-M 188mm 4 bolt axle flange or the stronger 210mm E46 M3 axle's 6-bolt flange we have installed.



Mounting this was completely straightforward and the 3.0" OD tube just cleared the factory center-bearing stamped sheet metal brackets in the tunnel. If it is too close there for your comfort, just trim away those stamped sheet metal mounts in the tunnel - they are no longer needed with this one-piece unit.



One less thing on our punch list, and one more part to add to our E46 LS swap kit offerings.

LEXAN WINDOWS ARRIVED

After months of waiting a large Lexan order came in from a new plastics / window supplier in November - who we will never use again. We ordered plastic for 5 different cars and they screwed up over half of the order - live and learn.



We received the back window pre-cut but the side windows they didn't have patterns for (but never told us) so we just have some curved stock we will have to cut to fit. Will show more of this next time. Again, we will NOT be using a plastic front windshield, and instead will use 2-layer bonded safety glass windshield, for various reasons.

SPARE TIRE WELL REMOVED

Another mid-November task was removing the spare tire well. We do this on any build where we have plans for a diffuser, which we do on this car.



The old stamped steel bits weighed 11.8 pounds, and will be replaced with some aluminum sheet metal, probably .080" thick. More on that later.

MOUNT OIL COOLER

After the protracted radiator mount task it was time to mount the only other front mounted heat exchanger on the list - the engine oil cooler. Remember, for WRL GTO we can only make around 275-330 whp, depending on our final weight, which should be easy for our 5.3L engine. But the 385" / 6.3L engine that is going in later it will make closer to 500 whp - so we are sizing all of the coolers for that power level (which we could run in AER events or NASA ST/TT classing).



We had a leftover Setrab cooler (below left) we could have used for engine cooling, but we're going to overshoot all of our cooler sizes and engine oil is the most critical. So we'll save the smaller Setrab for a trans or diff cooler, and we popped for the largest "plate and fin" 10000 series Derale cooler for the engine oil (below right).



At this point we knew we had to save room for the OTR air filter and hose, so Zach built this oil cooler mounting bracket setup for the Derale.



There are 100 ways to mount an oil cooler and we went with s simple set of 1x1" aluminum channel, bolted to some aluminum angle that welds to the tanks. We got some pushback when I showed this on social media, but we always see the arm chair quarterbacks do this when we show details this closely. It will either work or it won't, and we should know during our first track test. This mounts on the front face of the radiator stack and covers about 1/2 of the total surface area. We have a thermostatic bypass for the oil cooler we will mount, of course, so we don't "over cool" the oil.



This stacked set of heat exchangers will be fed entirely from the lower M3 grill opening, with sheet aluminum ducting forcing air through the coolers and not around them. If we need more airflow we can cut some holes in the bumper cover. The upper grill openings in the hood will be used for the air filter.

REAR SHOCK TOWER REINFORCEMENT

Moving the rear springs from the stock "divorced" location (see below left) to a "coilover rear" location (our E46 endurance car, below right) moves the suspension loads for the suspension completely. Normally the shock tower only sees DAMPER loads, which is about 1/10th the actual SUSPENSION loads.



This is why we rarely move the spring location to coilover rear, unless there is a very compelling reason to do so. The stock shock towers were NOT made for full suspension loads, and although a few people have done it without reinforcement, it doesn't take much time or abuse to blow out the shock tower. We've seen this happen too many times with just damper loads on street cars, and without coilovers, you just don't press your luck on this E46 chassis.


We have made spherical rear shock mounts for a bunch of cars for a bunch of years, and we always design them for full SUSPENSION loads, because we cannot control what the end customer does with our mounts. We offer upper perches for our shock mounts, to make coilover conversion use possible. When we described what we wanted to do with this car to the guys at MCS they highly recommended a coilover rear and dual spring setup, so we went that route.



There are a lot of folks who cage BMWs and believe you have to throw a dozen bars in the rear - to tie into the subframe mounts, to reinforce the shock towers, and more. They often end up with jungle gyms in the back seat - but we are not among the group that thinks this is necessary, and I am not getting into that argument here. After much internal debate on this subject, this (above) is what Zach and Myles came up with for our E46 with coilover rear damper and spring.

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The guys made a tracing of the inner sheet metal portions of the rear shock towers - which are NOT symmetrical - and made these CNC cut "windowed" reinforcement plates, then bent them to match. There were also top plates (also not symmetrical) that were cut out and the inner edges "curved" to match a fillet in the sheet metal. This is made to "box" the shock tower reinforcement and give some impact strength to the top of the towers, where they usually fail.



Zach cleaned the towers and MIG welded these along the edges plus some rosette welds in the holes added to the structure. We have some clean up work to do but they are pretty beefy. I will show more of this in the next update once it is cleaned up, primed, and ready.

MAKE TEMPLATES FOR TRUNK + FALSE FLOOR

A number of things that we chopped up needed some aluminum panels to replace them, like the trunk floor - that was an easy template, but we're going to wait and cut that until we have mounted the remote fuel surge tank + both the diff and trans coolers and pumps.



We also want to make a raised "false floor" for the driver's side. As you remove carpet bits the floor becomes very "not level", as shown above right. The left side drops down nearly 2 inches, and there's a rib in the middle of the pedals. The foam insulation under the carpet is 4+ inches thick in these areas to make this "flat", but carpet is long gone in this one. And driving a car with a funky floor is distracting - we always try to remove distractions to the driver!



A "false floor" covers up all of the uneven floorpan issues with a rigid, drop-in section of aluminum that normally incorporates a "dead pedal" on the left side. We have made these for a number of cars but never an E46 with the stock pedals, so this might be something we want to replicate and possibly sell some day, so some extra thought went into the template.



After I spent some time showing Zach what I wanted in this false floor panel panel he whipped up this template with integrated mounting tabs along the perimeter. I feel we might need a reinforcing rib or stand-offs along the centerline, but we'll make these adjustments to the prototype when we cut this out. Next time we should have the first iteration cut, bent, and in the car.

CHANGE EPAS COLUMN MOUNT & DASH BAR

The Prius steering column mount has changed a couple of times on this build already, but it was always a kludge. I kept trying to push the idea of a "kit" that we could sell for an easy EPAS upgrade - any development work we could push to a product solution was a win. We were also debating keeping the E46 dash bar, but already had to cut it to get the down tubes in place, but tacked the rusty tube back together for the time being. Then we added the real dash bar for the cage so we had TWO dash bars. This is less than ideal...



We kept parts of the OEM dash bar because I really wanted to keep the Prius' tilt mechanism and make the column a bolt-on affair. Without a bunch of diagrams, videos, or more words - this is just not possible with just a "bracket", and this frustrated all of us.



The tilt wouldn't work and the angle of the column was all wrong, not to mention it had a lateral offset. So we punted on the "bolt on" idea and ordered a real dash tube column mount.



After looking at a lot of brands and options (many of which were out of stock due to the pandemic), in mid-January Tim found this Keyser billet aluminum adjustable column mount. It was the closest thing to the diameter of the Prius column - with a little machining on the lathe it fit perfectly.



In late January, Tim, Magan and Myles got this assembly in the car and we started "Test sitting" the full range of heights of drivers, from Tim to Magan. This will not be adjustable "on the fly" like the OEM Prius column adjuster could have been, but they found a height that fit all of the drivers. This will allow us to cut away much of the OEM dash bar, but some of the structure will stay to hold the skinned dash cover.



This was also when we determined that the 320mm steering wheel was too small and found a 350mm wheel that better suited our needs for endurance racing. Slow the hands down for more control, less twitchy. There is one more small bracket that will be added to the column, to support the front end, then we can call this task complete. And more importantly, we can move onto the firewall bearing mount, build that last piece of the steering shaft, and wrap up the steering system once and for all.

OTR COLD AIR & FILTER MOUNT

There are many ways to get filtered air to a V8 engine with the throttle body at the front. This is often compromised by the radiator being close to the engine so we often make a 90 degree turn and put the air filter in an area sealed away from the engine compartment, where it can get "cold air" instead feeding the engine hot air from the radiator exhaust. This tubing, filter and air filter housing combined are often called the "Cold Air Intake", or "cold air" for short.



I am a big proponent of running the biggest filer element you can fit, and there are calculations and flow rates for any given filter. You also need to watch the tubing size and run as large or larger than the throttle body you have. We found out the hard way that running a 1/2" smaller tubing size than the TB can eat a big chunk of power - 15-25 whp can be choked off on a mild LS engine (we had to re-make the cold air intake on the FR-S above and found nearly 20 whp).



The 90 degree bend also costs power and the engine bay can limit the size of the filter element, which can limit airflow. Getting the cold air tubing "Over The Radiator" (OTR) can give you a BIG area ahead of the radiator to stick a giant air filter - like we did on "Big Red", our 2011 Mustang we ran for 5 seasons. But there was still a 90 deg bend that was even compressed a bit to clear the (modified) under hood structure.



With our rolled and lowered radiator mount we can still sneak a 4.5" silicone hose between the bottom of the upper radiator support and the coolers, and the whole cold intake tract is only 10" long and has one 30 deg bend. This massive C6 Corvette replacement K&N filter fits entirely in front of the radiator support and is still well behind the hood's upper grills.



I ordered the silicone hoses weeks ago but all of our shipments have been delayed due to the crazy winter storm last week. I will show the installed silicone tubing and filter mounting bracket next time, but just mocking this up made me extremely happy.

WHAT'S NEXT?

We have covered 8 months of work this time - and remember, it was almost all done a couple of hours one night every week. But the punch list is still large. The entire fuel systems needs to be built, as well as the exhaust (which we have parts on hand for). The false floor needs to be completed, as does the steering column/shaft.



Once the steering and some chassis wiring is done we can put the dash pad back in, then we have to order the digital dash display, finish the switch panel that Magan made and add switches and dials. Then install the Holley EFI system. Make all of the coolant lines, lots of oil lines, diff and trans coolers, flares cut to fit and installed, lower side skirts installed (parts here), side mirrors chosen and installed (you don't want to know how long I've looked for good options there!), and more.



Given my propensity to post memes, Zach printed out this one (above right) with a target date for the car to move under its own power - April 10, 2021 - which is 24 months to the day after we started this build. Let's push push push to make this goal!

Thanks for reading!

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Project update for June 29, 2021: It has been a few months since my last post here and we have some solid progress to share this time. No, it still isn't on track yet, but we do have a finished cage, window nets, steering column, painted interior, and the engine bay is much further along - and we've begun plumbing work.



We have been very busy with an onslaught of orders so I am more behind forum build thread updates than we are on actual project work. We have added a full time welder to our team to handle production fab work, which frees up Zach to do more car specific build work. Zach has been putting in the most hours on the Team Car this year, making up for a late start on the team. He's also a former Formula SAE builder and active autocrosser, so we have us another driver, too.

LEXAN REAR SIDE WINDOWS BUILT

In early March I stole Brad away from customer car work for a few hours to tackle the side quarter window install during shop hours, since he always does such a clean job of these Lexan installs.



Last November we made a huge Lexan purchase for 5 cars, and about half of that worked out well. To save $$ on the Team Car we bought some slightly curved blank sheets, then in March Brad made a template in cardboard from another E46 coupe's Lexan windows and then transferred it to this blank sheet. He carefully cut both rear windows out...



With a number of M4 rivnuts added to the frame of the rear side window opening he transferred the holes to the Lexan, then tackled the outer window trim that runs from the front to the back on an E46 coupe. It needed some clean up and paint, so it will be this satin black when installed after paint.



Brad then countersunk the holes in that for the Tinnerman washers and countersunk M4 stainless bolts. since our blank sheets weren't long enough, we decided to cut the windows a bit short and sink the glass flush with the metal B-pillar, shown above right. I had wanted the leading edge of the quarter glass to extend forward then curve inboard for some drag reduction, like on the '69 Camaro below.



On that car I bought some Lexan that was .093" thick from a local store and Zach and Brad built custom quarter windows with that inboard tilting leading edge. Zach experimented with several bending techniques and settled on just putting it in the sheet metal box and pan brake, then giving it a light bend - which stayed. We will take some small scraps of this thinner Lexan and make the leading edge bends for the E46 coupe in the future.



Last but not least, Brad peeled back the protective film and marked off a 1" border. This was scuffed and painted black, as shown. This helps hide the ugly sheet metal underneath the edge of the Lexan. These windows won't be reinstalled until right before the track test.

MORE WORK ON COLD AIR / RADIATOR SUPPORT

As I mentioned in our last installment, we were looking at this K&N RP-5135 filter to use for an OTR routing. Making it fit under the radiator support was going to be tricky... we were building this car to use a 90mm throttle body



Myles and Zach mocked this up and it looked massive and perfect - just needed to order some hose to get to the final location.... that silicone hose with a 15 deg bend arrived a couple of weeks later and then the guys trimmed up the back side of the upper portion of the radiator support to try to make this massive air filter fit.



I had my heart set on a "ram air" setup with a sealed airbox behind the filter, but after several cardboard mock-ups (see above) it was looking very constraining to both the filter and proposed hose routing to the radiator. Without an all new radiator placement or a completely different filter shape, this wasn't going to work. We already had too much time in this rolled radiator mount and I wasn't about to contemplate starting over - just for some mythical "ram air" that isn't even shown to be quantifiably better than "non-ram air" intake setups.



So Zach proposed cutting the radiator support upper section off. I wasn't having it - that could ruin the whole front end structure, hood mounting, etc. "How much did this radiator support cost?" Well, yea it was only $50. So sure - cut away! Worst case we just buy another. Lo and behold - even with the entire center "bridge" cut away the structure was still very rigid. I was wrong on that, thankfully, and we all felt good keeping this modified radiator support as the basis for our hood latch pins.



Once that was trimmed it opened up all sorts of possibilities! We could then slide the filter forward of the radiator (which was confined by the upper support and length of hose we had with that 15 deg bend). I ordered another 3.5" piece of hose, then a Vibrant coupler. I will show the rest in another section below.

CUSTOM RADIATOR HOSES BUILT

With the upper radiator support cut away it was time for Tim to step in and sort out the radiator hoses. This can be tricky as it is rare that you get to keep the same diameter at both ends of a given hose, and we often have to use "adapter" hoses that we splice together.



We used this rotating thermostat housing at the water pump that lets us "clock" the outlet within a range of angles. Tim has laid out the hoses on a number of builds and knows a few brands to go to for the bends and couplers.



This is the final result of the upper and lower radiator hoses, which match the Griffin radiator we ordered and the LS outlets. Clean routing, nothing crazy. When the air deflector (see that task below) went back on with the hoses in place, there was a slight tweak to clear them, which we will clean up further in a later task.

PRIUS STEERING COLUMN MOUNTING + STEERING SHAFT

We finalized the Prius steering column location and mounted it with the Keyser bracket to the dash bar last time, but we all felt it needed a "bit more" stability.



Myles tackled this task - he took a bent bracket that came with the Prius column, then added some tubing to connect that to the BMW's steering column mount bracket.



Kind of a funky shape but it all fits perfectly, and with the assembly fully TIG welded the column has proper support for the heavy motor hanging off the side of the electric assist column. Now that the top of the column was located properly we could focus on the firewall mount and then build the steering shaft. Some of the work below happened after the interior paint...



We worked through several ways to secure the steering shaft at the firewall - as we had removed the OEM support there, due to our non-BMW steering column. Like we have done on many custom steering shaft solutions, we utilized a common race car flange kit that sandwiches a spherical bearing. Then Myles CNC plasma-cut an adapter plate (above at left) that was welded to the large opening in the firewall. The 2-piece flange kit now bolts to that and the 3/4" DD shaft passes through this spherical for proper support.



The steering shaft is a simple design using parts we developed in 2006 - but unlike most of our 2-piece steering shafts, we had to weld the U-joint to the upper 3/4" DD shaft section. Why? The set screws were in a weird place, since this was such a custom application. So Myles TIG welded that junction. Everything else is bolted together with the set screws (with drilled detents on the shafts and red Loctite holding it all together.)



With a 2-piece 3/4" to 1" DD collapsible shaft assembly and our BMW 54 spline lower U-joint. You can see where we had each shaft size section in the picture above left. The above right pic was after the interior was painted and shows where the spherical shaft bushing mounts to the welded plate on the firewall.

INLET AIR DEFLECTOR

The new placement of the large K&N filter and subsequent removal of the radiator support's upper bridge removed a good place to hang a "cold air" box from, but also allows more airflow to and around the air filter.



To guide the path of incoming air from the upper grill openings (in the hood) we decided to build an air deflector. This would separate the air from the upper grill (which will feed the air cleaner) and the lower grill (which will feed the radiators).



Zach made a cardboard template then transferred this to aluminum sheet. The plan was to incorporate mounting into the existing upper radiator mounts, seal off to the front bumper cover and mount to the bumper beam as well.



There are still some small details to complete but this should wrap up most of the work that went into the air intake, air filter, and air deflector. Excess air that gets past the filter is aimed at the the top of the engine bay, and should be pulled out of the large vents in the carbon Seibon hood.



While working on this air deflector Zach also built some additional bumper cover brackets, shown below. This was something I asked the crew to tackle, as we only had a few points of contact with the bumper cover to the chassis.



LEXAN REAR WINDOW

This was the only pre-cut piece of Lexan we got in the large 5 car order that was utilized on this E46. Luckily this one fit well.



Once again I asked Brad to tackle this - and he pre-drilled the holes in the Lexan and added the mating rivnuts to the chassis.



More stainless M4 countersunk bolts and Tinnerman washers spread the load on the hardware to keep the Lexan from cracking. The window is mounted well enough that it should not need any support bows in the back window - but if our first track test shows some flutter on the back window we can cut and bend up some aluminum supports to span the vertical opening of the back window.

FINAL CAGE WORK

This was a last push of work nights to get the cage 100% wrapped up, then to add some cage-to-chassis plates, remove the last bits of metal inside we don't need, add window nets and mounts, as well as a panel to house the external fire bottle pull and battery kill. The goal was to get the car to the painter before the end of March, which we did.



Over several Team Car work nights Zach and Myles knocked out the final welding work, added a few small tubes, then finish welded the rear shock tower reinforcement plates.



Towards the end of this work I knew we were still missing something that we tend to add to all cages....

DIMPLE DIE PLATES!

That's what it was, these chassis tie-in plates. We made some simple steel plates that tied the cage to the A- and B-pillars, and of course added dimple dies.



Since I knew someone would ask, yes - these are legal for the classes we plan to run this car in. And also yes, we weighed them.



These were stitch welded to the A- and B-pillar as shown above and while they add some extra rigidity to the chassis, they add almost nothing to the weight. We're already going to have to add a LOT of ballast to run even close to 300 whp in WRL GTO class.

RANDOM SHEET METAL REMOVED

While this welding work was going on the guys chased a few more pounds by removing some unnecessary sheet metal structures inside.



Little seat belt brackets, rear package shelf structure we hadn't chopped away fully, and the battery box. The rear spare tire well was already removed by Tim previously.



This wasn't done so much for weight savings as clean-up of some quickly cut away parts, and to get us that much closer to being able to paint the interior and not regret leaving things unfinished.

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[Fair!]

continued from above

WINDOW NETS + EXTERNAL KILL SWITCH PANEL

There are always brackets needed for the outside window net, which needed to be added before the interior was painted. The owner at Safecraft is a racing friend of Tim's, and we sell their products. They donated a set of 6-point harnesses and three nets for our build - both left hand nets (driver's head net and window net) and a center net.



The first one to get a mounting bracket was the outside head net - which looks triangular like the center net, except that it has this very distinctive quick release(see above right and below). We will add the center net after paint - it doesn't need anything welded to the cage to attach.


"The Safecraft racing net features the easiest to operate release buckle we have used. The pin is easy to insert into the tapered buckle. The outward facing red release button is easy for rescue personnel to identify and operate, and the inward facing release strap can easily be pulled even with gloves on. Because the pin is round, you don't have to worry about removing any twists in the net before buckling it. This buckle makes for quick driver changes, and is the most fumble free available.



Zach fired up SolidWorks and designed this bracket above, based on measurements he took. This was then CNC plasma cut, cleaned up and bent. The extra holes will hold the secondary fire pull and kill switch.



The very distinctive Safecraft quick release mounting cup has a threaded shaft that was welded to these stand-offs, as shown above.



Then this bracket Zach made was welded between our cage's A-pillar and FIA vertical bars. This makes for a solid mounting for the driver's head net Quick Release - which can be reached from the driver inside the car (via the red Nylon pull) or outside (the big red button). Once you use these quick release pins from Safecraft you don't ever want to mess with anything else.



The separate outer mesh net is the "window net", which is what FIA wants to see - to keep debris out of the car. Having two nets seems overkill, but this is what ALL pro teams do on "windows down" cars like this. This Safecraft net is held in with an upper bar that has a spring loaded bracket (both brackets are welded to the cage) and straps to wrap around the door bars from below.

INTERIOR METAL CLEAN UP FOR PAINT

Last but not least was the nasty job of cleaning up the sheet metal and cage tubes before the car went to have the inside painted. Everyone pitched in for this nasty job.



Every bit of sound deadening that was left had to be scraped / wire wheel removed. The "crud buster" tool above was used quite a bit, as was a lot of Scotch-Brite red pads - and the entire cage was cleaned up of any residual rust or weld spatter.



I cannot emphasize enough how much this job sucked - it just spit a lot of crud onto anyone involved, and even wearing full face masks and breathing filters, you got filthy everywhere else. But the more we cleaned, the less the paint shop would have to, and the better the paint job we would get for the money.



On March 26th we had wrapped up all welding and clean-up work on the interior, and rolled the car outside for the first time in over a year. We had the ride heights mostly set, the big wheels and tires installed, the caged wrapped up, the doors and trunk off, and the windows removed - and it still looked pretty mean.



The next day (a Saturday) I loaded the car into the enclosed trailer and took it to our painter, so they could get started on the interior paint work.

INTERIOR PAINT WORK

We took the E46 to our preferred painter, Shiloh, at Heritage Collision up in Sherman, TX. Shiloh and his crew have painted dozens of cars for us and our customers, and he is the "go to guy" in Dallas/Ft. Worth for racers who need body and paint work. He also does show quality level paint, insurance work, the whole gamut.



Shiloh helped me unload and we brought the car into his shop, where we were greeted by the two new shop kittens. We had spoken a couple of weeks before about the hard PPG interior paint he wanted to use and I asked him to order a color that was "red AF". And that he did! We are still up in the air about the exterior color, it could be this same shade of red or white or black. We shall see....



Shiloh and his guys cleaned and prepped the sheet metal and cage even better than we did - I was embarrassed by how much better they made the inside look. But they take every job seriously and it results in a better finish.



They taped off the exterior but painted the complete trunk area, and sprayed 4 coats of this hardened urethane - which wears very well on cages.



Shiloh is great about sending progress pictures throughout the build, and there were no surprises when we picked up the car at all.



I picked up the car on April 7th and was blown away at how good the paint work looked when the car was rolled outside. It was bright, shiny, Red AF and made this $100 chassis look like it was worth at least three times that much! The shop kittens were helpful when inspecting the work.



We got the car back to the shop and brought it back inside... then it sat for several weeks while "life got in the way".

DEFROST VENTS BUILT

We all got busy in May and skipped a few weeks of our Thursday work nights. Zach was autocrossing a lot, Tim was doing Pro race support, Myles had a new baby, and the rest of us had tons of other stuff going on. But Zach got back to the work first and tackled this task in early June.



I really want our endurance car to have at least the shell of the OEM dash, and while this is something some team members disagreed with me on, so far I'm winning this battle. The example above shows a one-piece aftermarket plastic dash skin in another BMW race car. Our E46 will not look quite that clean - but this is about how I want our car to look.



We kept the original dash from this car (very gutted and much lighter), and in previous entries on this forum I've shown what we did to make it fit. That has been out for a bit while we worked on the cage but it still fits. We also want to run a motorsports style heater box/defroster. We've used the box (above right) on many builds and it is both cost effective and lightweight.



Why run a defroster? Well we do have events here in Texas in cold months. The January 2016 NASA event (above left) in my C4 - which had no heater - was a nightmare of a frozen windshield and foggy forward vision until the sun came out and thawed us all out. For about 8 pounds we can have a proper heater box, which we always point at the windshield.



Instead of making the ducting manually, we kept the stock defrost ducting on the BMW dash. There is a junction in the plastic manifold that had a flat but funky shape...



Zach made the two parts above. One can act as a block off plate and the other has an adapter for the 3" hoses that matches the defrost box outlet tubes. We will plumb one of the two outlets to the dash here and another to the center vent - to only use on very cold track days. It will keep the windshield fog free and - with the center vent opened - can put some heat into the cabin for times when you might be sitting in paddock or taking slow laps before the green flag drops.

TRUNK PANELS ADDED

We plan to add a functional diffuser to this car, and as part of that plan we ditched the spare tire well and deep battery box in the trunk already.



After the car came back from paint, Zach worked one night and built this aluminum flange that will hold the flat trunk floor panel. That panel was measured, added to CAD, and CNC plasma cut from some steel sheet. We used steel there to add rigidity, and to be able to weld to later. We will likely add a diff cooler, fans, and some other things to this panel. It will be painted after our first track test.



Zach also designed and plasma cut two other panels. They both cover up the "vent holes" in the trunk, which are used to expel air pressure from the cabin when you close the doors with the windows up. Well our cabin will never have door windows, so those got covers. The second panel also serves as the new battery tray, higher mounted than the deep OEM piece.



The image above shows the steel trunk panel set into place and the two side vent block off panels + battery tray riveted in place. Look for more action back here in future entries. The pic above right is from another E46 we built where we did the same thing - made a battery shelf because of a huge diffuser underneath.

A DIGITAL DASH OPTION WE ARE TESTING

PowerTune Digital is out of Australia and they make this 7" LCD digital dash display for $500, which has CAN support for dozens of ECUs, including many OEMs. The screens are completely configurable, they have an optional GPS antenna, and we wanted to check them out.



They just released Holley CAN support and we are testing the first one on an actual Holley EFI car now in our shop, on another customer's endurance LS powered Holley Terminator X-Max equipped car...



This Cadillac was begun much later than our E46 but is getting done a lot faster - it is a customer build, so it gets priority shop work during business hours. We're just building our E46 a few hours over one night per week.



Anyway, we made the image above to show the various AiM and Holley digital dash unit sizes, and the 7" PTD unit is as big as the large AiM but is $2100 less. It is going into this CTS-V and also my wife's narrow body C6 Corvette for testing. If we like how it works we will put one in the E46 here, too!

WHAT'S NEXT?

We have a lot of parts on hand to add to the E46, like this coolant reservoir, oil catch can and accumulator from MasterLube. Getting all of these items mounted will let us plumb the oil, coolant and fuel systems on the car.



We also installed this ICT Billet power steering delete kit, which will be run with a different routing than what I mentioned in the February post.



There are hood latches to add, seats to mount, harnesses to install, and wiring to tackle. All work we have done before, just need to get it going.

Until next time, thanks for reading!