m20 Dual exhaust?

[kidrobot]

Might help, maybe not, but I'm running dual 3" on my turbo'd.
Easiest way to do it is to get a Y-pipe. I have my Y spliced
and set right underneath the front seats. I had cherry bombs
on it for awhile, along with the remus. Sounded evil. :twisted:

I took of the cherries though because they're too damned loud
and the neighbors complained when I left for work. btw cats
are for girls. :D

[SickE30]

hey kid check your pm's bro.

[PeterCip]

there is a guy at most of the local driving events who rocks a e30 retrofited an e46 M3 dual setup and muffler on his car.. sounded like crap in my opinion..
The HMS motorsport guys probably recognize him.
-pete

[Digitalwave]

there is a guy at most of the local driving events who rocks a e30 retrofited an e46 M3 dual setup and muffler on his car.. sounded like crap in my opinion..
The HMS motorsport guys probably recognize him.
-pete

His name is Pete, he is the guy with the M50 mentioned earlier in this thread.

Dual 3" pipes are rediculous. The only decent looking dual exhaust I have seen is on Rui's E30 M3.

[Bryson]

why not split into a single pipe and have a cat and muffler under the car, before the rear subframe, then after the muffler, split into two pipes running to a dual exhaust, that would lower costs and eliminate any work with the battery tray and spare well... I thought about doing that to mine some day.

[rwh11385]

why not split into a single pipe and have a cat and muffler under the car, before the rear subframe, then after the muffler, split into two pipes running to a dual exhaust, that would lower costs and eliminate any work with the battery tray and spare well... I thought about doing that to mine some day.

I haven't taken fluid dynamics or whatever yet, but i'm pretty sure that would create unneccessary turbelence and decrease good exhaust flow.

Either run stock size or slightly larger dual pipes ALL the way through.
OR run one huge single pipe, like Ted.

[Bryson]

that's interesting, especially since our M cars come with an x-pipe, I always understood that the 2-1 thing was good for the engine, and you could do whatever after that. There's a nice article on gustave's site that explains it, BMW took time to research where to put the x-pipe for the best gain, that's where I'd make it into a single, then dual it right before the subframe, or even right after

edit: here's a linker http://www.e30m3performance.com/tech.../cntr_sect.htm

[rwh11385]

that's interesting, especially since our M cars come with an x-pipe, I always understood that the 2-1 thing was good for the engine, and you could do whatever after that. There's a nice article on gustave's site that explains it, BMW took time to research where to put the x-pipe for the best gain, that's where I'd make it into a single, then dual it right before the subframe, or even right after

edit: here's a linker http://www.e30m3performance.com/tech.../cntr_sect.htm

"A detailed explanation of this phenomena will not be given here, but the theory is that as individual exhaust pulses move down the exhaust tract, they leave behind them a negative pressure wake. If the exhaust pathways come together at just the right places, then these negative pressure wakes can help "suck" on neighboring cylinders in such a way that those cylinders achieve much higher filling then they would on their own."

I think you could create an exhaust that uses the X-pipe theory to yield more horsepower. But you'd have to dyno tune it to make sure.

I think what you're talking is really more closely related to the header design, as crossing the streams must later wouldn't be the same idea as on the M. I'm not sure I understood what you were describing in the first post.

If one could create an X-pipe that connected to the exhaust manifold and see the results, that would be very very interesting. After the X-pipe, the exhaust could continue on its dual system.

Of course if you use a Y-pipe and funnel all the exhaust into one pipe, and split it to dual exits in the end, i don't see the point besides cosmetics.

Whatever, this is an intriguing topic.

[Bryson]

the point of an x-pipe is to give the effect of a y-pipe while still retaining two pipes for clearance reasons. You could just make it a y where the x would have been and recieve the same results, then, for cosmetic reasons only, run a dual setup (one pipe on left of car, one on right=badass)

edit: the point of 2-1-2 is so you can use a single muffler that is small and will fit under the center of the car, making it possible to fit the pipe on the right side without cutting anything

[golde30]

a 20 to get passed??? dammit..im in the wrong state...i live in CA, and my turbo datsun is the biggest pain in the ass to make pass smog...the cheapest i have ever gotten it passed for is 200!!!!

[nando]

emissions checks? what are those? ;)