Re: McCall's Z3 M Roadtser LS1 Project
Project Update for Nov 11, 2011: Some folks on the various forums we're posting this build thread are anxious for updates, and I'll share what we've done lately. We abducted McCall's Z3 and brought it to the new shop in October. The last 2 weeks we've been planning the exhaust layout and accumulating parts to start making custom exhausts here at Vorshlag's new shop, with McCall's Z3M LSx exhaust being one of our first ones tackled (followed by a custom "axle back" system on my 2011 GT). First up, Ryan and AJ got the Z3 in the air and planned out the dual 3" exhaust routing.
The Z3 is one of the few BMW chassis that has room for a true dual exhaust, and even though it doesn't "need" a dual 3" system (even at 450+ whp levels), it just sounds better and that's what McCall wanted. Can't blame him - I'd do that in all of my BMW V8s if it didn't require hacking out the trunk floors and custom fuel tanks to pull it off in the other 3 series chassis. This system will start at the V-bands on our production full length headers, go through two high flow catalysts, then merge into a custom-built "X" in the middle, then split back two dual 3" paths traversing under the diff, and head to two mufflers located near the rear bumper, with two polished tips at the back. We will TIG weld the entire system, built with the various 45 and 90 degree mandrel bent sections and straights.
We have also been doing a week+ of research and finally found good sources for stainless exhaust tubing. We tried to find a good supplier for 18 gauge (.049" wall) 304SS tubing, but try as we might the costs and selections just suck. We ordered several sample bends last week from a few sources that we got from internet research and from asking in these threads, and the results were less than ideal. One bend showed up and was actually 16 gauge (.065" wall) and was a bust. Another was some Chinese polished nonsense that had ends crimped on for inlet tubing. Questionable bling. One wasn't even stainless. Lots of flops on anything remotely cost competitive to 16 ga.
All of the other legitimate, US-sourced, 18 ga 304SS tubing was 2-3 times as expensive as 16 gauge, even from the same sources (you pay more for less steel?), so we're going to punt and gear up to use 16 gauge for systems - like everyone else does. The demand for 18 is so small that the smaller number of sources just charge more for it. 16 gauge exhaust tubing is just SO much more plentiful and affordable. I weighed the pros and cons, and talked over the costs with McCall and he agreed - and its not worth the extra hundreds of dollars in material costs to save "ones of pounds" on an entire exhaust system. My overwhelming desire to drop weight from a race car has a cost, and its just "too much for too little" in this regard. Yes, we'll make custom 18 gauge exhaust systems for people that must have the lightest system possible, but they're going to have to pay 2-3 times as much in materials and we will just have to pre-order the bends for their jobs.
So long story short, we're finally getting the materials needed for McCall's dual 3" exhaust rounded up. We've found several stainless 3" band clamps we're going to try, sourced some nice tips for the back, and have the mufflers on hand. The 45° and 90° mandrel bends are being made to order and should be ready to pick-up today.
Oh yea, the mufflers - The ones we're using on his car are the same style I've used many times before, from Flowmaster, and I bought another pair for the Mustang as well (that car is freakishly quiet with the stock mufflers, even with ARH long tubes installed). Their new Series 44 409SS offerings look nice and are fairly lightweight for a 3" full sized, mufti-chambered muffler. I like them because unlike the "fiberglass matting" packed mufflers, these don't seem to "wear out" the insides and get louder over time (like all of the glass-pack style mufflers I've used over the years; yes, even the FM Hushpowers). I know these will sound good and knock down decibels, and at 9.6 pounds they aren't going to add much weight. Now that they have a stainless option, and at only $85 each, this was a no-brainer. You won't get much lighter in an effective 3" In/Out muffler, honestly. The ultra-light stuff, like the 3 pound Burns stainless mufflers are over $300 each and they just don't cut down much on noise, and will get louder over time.
More soon,
Project Update for Nov 11, 2011: Some folks on the various forums we're posting this build thread are anxious for updates, and I'll share what we've done lately. We abducted McCall's Z3 and brought it to the new shop in October. The last 2 weeks we've been planning the exhaust layout and accumulating parts to start making custom exhausts here at Vorshlag's new shop, with McCall's Z3M LSx exhaust being one of our first ones tackled (followed by a custom "axle back" system on my 2011 GT). First up, Ryan and AJ got the Z3 in the air and planned out the dual 3" exhaust routing.
The Z3 is one of the few BMW chassis that has room for a true dual exhaust, and even though it doesn't "need" a dual 3" system (even at 450+ whp levels), it just sounds better and that's what McCall wanted. Can't blame him - I'd do that in all of my BMW V8s if it didn't require hacking out the trunk floors and custom fuel tanks to pull it off in the other 3 series chassis. This system will start at the V-bands on our production full length headers, go through two high flow catalysts, then merge into a custom-built "X" in the middle, then split back two dual 3" paths traversing under the diff, and head to two mufflers located near the rear bumper, with two polished tips at the back. We will TIG weld the entire system, built with the various 45 and 90 degree mandrel bent sections and straights.
We have also been doing a week+ of research and finally found good sources for stainless exhaust tubing. We tried to find a good supplier for 18 gauge (.049" wall) 304SS tubing, but try as we might the costs and selections just suck. We ordered several sample bends last week from a few sources that we got from internet research and from asking in these threads, and the results were less than ideal. One bend showed up and was actually 16 gauge (.065" wall) and was a bust. Another was some Chinese polished nonsense that had ends crimped on for inlet tubing. Questionable bling. One wasn't even stainless. Lots of flops on anything remotely cost competitive to 16 ga.
All of the other legitimate, US-sourced, 18 ga 304SS tubing was 2-3 times as expensive as 16 gauge, even from the same sources (you pay more for less steel?), so we're going to punt and gear up to use 16 gauge for systems - like everyone else does. The demand for 18 is so small that the smaller number of sources just charge more for it. 16 gauge exhaust tubing is just SO much more plentiful and affordable. I weighed the pros and cons, and talked over the costs with McCall and he agreed - and its not worth the extra hundreds of dollars in material costs to save "ones of pounds" on an entire exhaust system. My overwhelming desire to drop weight from a race car has a cost, and its just "too much for too little" in this regard. Yes, we'll make custom 18 gauge exhaust systems for people that must have the lightest system possible, but they're going to have to pay 2-3 times as much in materials and we will just have to pre-order the bends for their jobs.
So long story short, we're finally getting the materials needed for McCall's dual 3" exhaust rounded up. We've found several stainless 3" band clamps we're going to try, sourced some nice tips for the back, and have the mufflers on hand. The 45° and 90° mandrel bends are being made to order and should be ready to pick-up today.
Oh yea, the mufflers - The ones we're using on his car are the same style I've used many times before, from Flowmaster, and I bought another pair for the Mustang as well (that car is freakishly quiet with the stock mufflers, even with ARH long tubes installed). Their new Series 44 409SS offerings look nice and are fairly lightweight for a 3" full sized, mufti-chambered muffler. I like them because unlike the "fiberglass matting" packed mufflers, these don't seem to "wear out" the insides and get louder over time (like all of the glass-pack style mufflers I've used over the years; yes, even the FM Hushpowers). I know these will sound good and knock down decibels, and at 9.6 pounds they aren't going to add much weight. Now that they have a stainless option, and at only $85 each, this was a no-brainer. You won't get much lighter in an effective 3" In/Out muffler, honestly. The ultra-light stuff, like the 3 pound Burns stainless mufflers are over $300 each and they just don't cut down much on noise, and will get louder over time.
More soon,
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