will M3 cats work?

[sm32589g]

i am thinking about putting a supercharger provided by AA into my 1999 323is. i was just wondering if i could also install the m3 cats in my car. i believe the flow would be alot better considering my current custom exhaust has a weird kink after its cat. my curret system goes from a small hole to suddenly 2 large holes.

will the m3 cats fit? also will if work well for my car? help me pass smog? btw im in cali.

thx

 

[sm32589g]

ok i didnt want to rush to conclusion but ive decided since this board is nowhere near as helpful as it used to be, can someone at least respond to tell me how to withdrawal my membership?
btw i dont expect a response as that would not be abnormal.

 

[Big Daddy]

Wow a little feisty? Here we have a person asking a favor, information on a subject he/she does not have the specific knowledge they need and because three days later someone has not responded they want to cancel their membership?

M3 cats will not directly fit your car, different size exhaust piping, but you could use a reducer and make them fit, however that said I do not believe you are going to see any added benefit from them. Should have no effect either way on the smog tests.

I can cancel your membership for you.

 

[sm32589g]

ok maybe i over reacted but its just that evertime i post something on here noone ever replies its a continuation of things not just this once. this board used to be more helpful and big daddy is the only one who ever replies to my posts. lol

anyhow do you happen to know how many O2 sensors and the locations there are?

what i am trying to do is pass smog. im going to be putting an AA supercharger and i want to be smog legal. i igure more cats the better or am i mistaken? also the flow would be more even throughout.

 

[Tom]

Yeah I was out of town. You're better off getting a new exhaust system with a high-flow cat vs. installing a stock M3 cat on yours.

 

[Tom]

anyhow do you happen to know how many O2 sensors and the locations there are?

There are two o2 sensors. One before and one after the cat.

 

[sm32589g]

ok thanks.
when u say performance u mean like an aftermarket say magnaflow cat or something? custom fabricated?

 

[Tom]

ok thanks.
when u say performance u mean like an aftermarket say magnaflow cat or something? custom fabricated?

Yes sir. Just make sure you get a catback system instead of just replacing certain parts of the exhaust and still using the same diameter piping.

 

[Big Daddy]

I agree with Tom, the BMW exhaust systems are very effecient and have great performance, so to improve that you have to buy a high performance catback system, not just performance parts hooked to the old system.

 

[sm32589g]

ok thanks
the reason why ima want to better my emissions is because im going to put S50 crank and rods and S52 cams into my M52 2.5 block. and i am not sure if i would pass emissions alone with that although i would be getting software for it.

also i believe the compression ratio is going to be about 11:5:1 is that too high? wat could happen? the M52 engine is beefire than the M3.