explain affects of Y-Piping the e30

[Brezzi]

Hi r3v,

When I bought my e30 it came with a hacked up stock exhaust. It is stock from manifold to the cat but right after the cat the dual pipe set up is cut and welded to a 2.25'' Y pipe. Now my cat is fine and not throwing an codes at the moment so I didn't wana go through the whole process of creating a whole new system however it came with this awful looking dented muffler on it so I got that thing off and straight piped it with a euro looking exhaust tip.

It was fun for awhile all types of pop's and gurgling going on when I shifted. However it is loud as hell and I'm not 17 anymore (more like the tail end of 25) so I bought a magnaflow muffler for it (http://www.jegs.com/i/Magnaflow/642/...dvEaAnvG8P8HAQ) and am currently working to get it on all while doing this I am thinking how will the muffler affect performance and more importantly how does the Y-pipe affect performance.

So in summation can someone weigh in on if the Y-piping of the stock system is a good or bad thing? Also should I see any benefits from running a proper muffler over a straight pipe? I've read that mufflers are better as they create a more fluid space for the air to flow through.

Any insight on this is appreciated.


Thanks!
Brent

[TheTacoMan]

I really don't think a Y-pipe at the end of the exhaust system will cause any issue or noticeable loss in power considering most m20s only make 150whp on a good day. Im looking into it on one of my fluid dynamic books but not seeing anything conclusive yet.

[Brezzi]

I really don't think a Y-pipe at the end of the exhaust system will cause any issue or noticeable loss in power considering most m20s only make 150whp on a good day. Im looking into it on one of my fluid dynamic books but not seeing anything conclusive yet.

haha yeah I didn't think it would have much of an affect if any but wanted to ask the more informed.

Do you think a larger single pipe like a 2.5'' or 3'' would be better or not really affect it that much?

[f4tj0n]

Too big can have negative effects when your motor doesnt breathe that much. You need back pressure.

[ak-]

Ummm, as long as it's not ridiculously restrictive in size, nothing after the headers really matter (besides your cat). Anything bigger than your current setup, whether you split or go straight, will all yield the same result N/A.

[Brezzi]

Thanks guys I'll stick with the 2.25'' single after the cat for now.