katokid Posted May 2, 2014 Author Share Posted May 2, 2014 Thanks for the compliments guys. I haven't been completely idle but life and work just keeps getting in the way...I have been plugging away on the air filter and exhaust system. There was no way the factory BMW air filter assembly was going to fit so I had to find an alternative. Ended up with the only K&N filter in their range that had the required 92mm ID to match my MAF. Its pretty fugly and far from what I envisaged but it works and I'm constrained by the oil cooler lines that run underneath. There's a bracket which you cant see that supports the MAF and filter coming off the engine mount below.I thought of running a tube through the radiator support panel and having the filter out front in a set up like the standard 280 arrangement but the hole in the radiator support is way too small and I didn't want to cut it up. As Ive stated previously the factory M3 exhaust system is a dual 2" system all the way and the aftermarket systems pretty much replicate this but go up to 2.25" all the way . Everything I read says that Bimmers drone like crazy with a large single and lose the signature Bimmer note if you go away from duals so I was pretty committed to staying with this format if I could make it fit..... with the condition that I had to have good ground clearance.I didn't want to use chambered type mufflers so I need as much length and volume in the straight through designs as I could fit under the car and hope that will get me through rego and still sound good and be nice to drive....we shall see! I had a custom stainless mid pipe resonator and rear muffler built to my plans. Resonator is as long as space would allow, there will be two 12" hotdogs under the diff and then into as large a rear muffler as possible with dual inlets merging internally into a single 3" outlet.I bought a bunch of 304 mandrel bends, V bands, hangers and other stuff and got into it.The factory headers are double 3 into 1's with the secondary pipe being 2". In order to be able to remove and refit the headers in the car I needed to have flanges as close to the end of the secondaries as possible, there was little room so V bands were the only way. Down stream from the V bands it goes straight into a 2" to 2.25" cone and then eventually via many bends and sections into the resonator.The two bits of wood in the photos are there to position the resonator while I built the engine pipe(s) and they sit hard up on the chassis rail for the front one and the back one is spaced down the corresponding depth of the rail so the resonator sits level in the car.After many hours of work I'm very happy with the engine pipes and the resonator fitment. Ground clearances is not compromised at all ....but things may get a bit warm inside the cabin as it is tucked up very high and close to the tunnel. I lashed out and bought Vibrant Performance V bands from Summit and very glad I did....very well made, full stainless (cheaper stuff isn't) and they have this really cool flip on flip off quick connect feature for the T bolt. I couldn't tell you how many times I have removed and refitted them in the process but it was heaps and they work brilliantly. I borrowed a BOC Inverweld 140 http://www.twi-global.com/industrial-membership/industrial-members-showcase/products/boc-inverweld/ which is a small portable machine. Its really a stick welder but can be set up to use as a TIG however it has ZERO features (hand or foot amperage control, pre flow, post flow etc) that you normally find in a decent TIG. I had never TIGed before so figured I would tack it with this and have someone experienced finish weld but after a bit of mucking around and going down to 1.6mm tungsten's I found I could get a pretty decent weld from it so have decided to do it all myself. As long as you get very good joins with no gaps you can just fusion weld with no filler, most of the time I enjoy it but every now and then it gets a bit ugly but Ive learned heaps and pretty confident now. Ive used generic "Toyota" rubbers which use 10mm push on rods. Ive used cheap mild steel rods for the top rods that have been welded to my modified suspension/front diff mount cross member as they will be painted but had to spend $70 for 10x stainless rods for the lowers. Mounted at 45 degrees it relies on the weight of the system to keep things central. There is some lateral movement as expected but its not enough to be a problem (I think) given the tight tolerances (I'm working with half an inch as minimums) and they are nice and soft so hopefully should provide good NVH insulation. Its not easy to see but there is a step down from the exit of the resonator to the inlet of the hot dogs, required to optimize the ground clearance for the resonator and the positioning of the hots dogs to clear the R200 diff. Also required was the turned in exits from the hot dogs to clear the the rear suspension. The step down loses me some about half an inch of ground clearance but cant be avoided. Exhaust is virtually finished, just need to make the front mount for the rear muffler and do the O2 bungs.Its been a much bigger job than I anticipated. Making it a dual system makes it much harder because you have to mirror everything ...if its a single system there is no reference so it always looks right but as soon as you introduce a dual system you can see where things diverge or converge or don't match and look pox if you don't take the time, especially so for this rear section.If I was doing this again I would do it in mild steel and coat it, stainless is just that much harder to work with. The welding bit is fine its the cutting and fine tweaking to get a no gap join so that you can fusion weld is the really time consuming part as stainless is so much tougher (hardness) than mild.Anyway I'm pretty pleased with the way it looks....just hope it is quiet enough and sounds good! Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 2, 2014 Share Posted May 2, 2014 Freaking beautiful. You need to park over mirrors wherever you go! Quote Link to comment Share on other sites More sharing options...
hwvigo Posted May 2, 2014 Share Posted May 2, 2014 That is one of the most stunning looking exhausts I have ever seen done the fit is perfect the execution is flawless I would go as far as to say it is elegant. Quote Link to comment Share on other sites More sharing options...
madkaw Posted May 2, 2014 Share Posted May 2, 2014 Just trying to find something you've done half assed so it will make me feel better- lol People call me a perfectionist and I couldn't hold a candle to you. It's a shame only a few qualified individuals will understand the level of work your doing. You have to do this level of work for yourself. Very entertaining , thank you for the detail of sharing Quote Link to comment Share on other sites More sharing options...
katokid Posted June 6, 2014 Author Share Posted June 6, 2014 (edited) Thanks for the compliments. I like detail and love to see it in other peoples threads, no doubt there are some people that can do without the detail but hey you dont have to read it. Last bits I had to do before I returned the welder to my mate was the rear mount, the tip and the O2 bungs. The tip was a matter of measuring and cutting, creeping up on it to get just the length I wanted. I probably should have hung the rear bar on it to confirm it still looks Ok. Also included a shot of the rear mount before I added the tip.....not much room up there but it hangs just right. There isn't much room for the O2 sensors and I was going to put them further downstream where I had more room but luckily I did some reading up and they require a minimum of 600 deg C to work properly. They actually have heaters in them to bring them up to temp quickly so they can monitor emissions on cold start. The bungs are the same length as the factory bungs at 25mm and are pretty close to where they were on the factory headers so should be good. Also they must be pointing upwards from horizontal so that the water from condensation on start up doesn't collect and damage them.....the things you find out! Edited June 6, 2014 by katokid Quote Link to comment Share on other sites More sharing options...
Nite_Grind Posted June 18, 2014 Share Posted June 18, 2014 Breathtaking! Can't wait to see this come full circle. This is by far my most favorite build I've seen w/ a swap. Keep up the good work. Quote Link to comment Share on other sites More sharing options...
SeanD Posted March 28, 2016 Share Posted March 28, 2016 Nearly two years down the road -any updates on this project please ? Quote Link to comment Share on other sites More sharing options...
Sirpent Posted April 3, 2016 Share Posted April 3, 2016 Lots Sean.................cars in the paint shop http://www.viczcar.com/forum/topic/4654-kato-kids-bmw-m3-powered-71-240z/page-28 Quote Link to comment Share on other sites More sharing options...
katokid Posted April 22, 2020 Author Share Posted April 22, 2020 (edited) Hi all. Apologies, I got so caught up in work and my build that I didn't have time to post here. Good news is that the car has been finished for a few years now and is an absolute blast to drive. No real issue to speak of and has been 100% reliable even on the racetrack. My full build thread here : https://www.viczcar.com/forums/topic/4654-kato-kids-bmw-m3-powered-71-240z/page/41/#comments Edited April 22, 2020 by katokid Quote Link to comment Share on other sites More sharing options...
HuD 91gt Posted April 22, 2020 Share Posted April 22, 2020 (edited) Awesome! Are you able to fill us in what rubber bushing was used in replacement? Edited April 22, 2020 by HuD 91gt Quote Link to comment Share on other sites More sharing options...
katokid Posted April 23, 2020 Author Share Posted April 23, 2020 Its the front bush for an RN90 Hilux rear spring 40mm OD Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted April 23, 2020 Administrators Share Posted April 23, 2020 Congratulations! Very nicely done! Quote Link to comment Share on other sites More sharing options...
Nelsonian Posted April 23, 2020 Share Posted April 23, 2020 4 hours ago, RTz said: Congratulations! Very nicely done! I agree 100% Quote Link to comment Share on other sites More sharing options...
katokid Posted April 23, 2020 Author Share Posted April 23, 2020 Took a while longer than expected Ron but got there in the end. Thanks again for all of your help. Quote Link to comment Share on other sites More sharing options...
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