e36 M3 cat-bypass or mid-pipe

[s6beebe]

is anyone using a cat bypass or mid-pipe, either with a resonator or not, on an e36 M3? if so, what are you using and what are your impressions? '95 M3s are no longer required to pass emissions and I'm looking for alternatives or even a 100 or 200-cell replacement option.

[bluptgm3]

I believe you will need a ‘tune’ to run better without the back pressure created by the ‘cats’.

Go for a single 3” system from the head pipes.


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[shogun]

moved to M3 forum

[RRSperry]

Just don't. Your car will smell like ass, and there isn't a whole lot you're going to gain... Please don't screw up my air more than you have too.

[Moron95M3]

Just to annoy Rich^^ ...I'm running full headers -> 3" midpipe -> UUC system U.

You do not need a tune for any of this, OBDI cares only until the exhaust exists the car (first and only 02 sensor). From there, the less restriction the better (in general).
My setup is very loud, I would blame some on the midpipe, and some on the 'cat'back. I don't track this car so butt dyno is irrelevant.

I would just do a catback unless you're doing other stuff (headers) that could require a new midpipe anyways. That's why I ended up doing mine.

PS I do love the smell

[s6beebe]

Just don't. Your car will smell like ass, and there isn't a whole lot you're going to gain... Please don't screw up my air more than you have too.

i doubt you'll smell it from dallas. now, if i still lived in westminster or finksburg...

[s6beebe]

Just to annoy Rich^^ ...I'm running full headers -> 3" midpipe -> UUC system U.

PS I do love the smell

appreciate the feedback. i run a cat-delete pipe on my 944 turbo and 200-cell cats on my 993 and neither car smells bad at all. i only ever ran cat-backs on my e36s, so there may not be much upside this time around either.
thanks.