Alternatives to CATs?

[m3f_Klint_c491bc5f79]

Hello There!



About 4-5 weeks ago I noticed my CATs were on the blink, In response to that I started a thread here where it was suggested that instead of getting the blocked CATs replaced with CATs, I should get "straight throughs" of somesort.



A couple of questions:

My car isn't a M3 but a 325i Coupe built in 94' so it has the VANOS if that makes any difference?



What options do I have in the aftermarket section for replacement CATs/straight throughs, Supersprint? Scorpion to name a few, do they make the part(s)?



What can I expect in terms of performance changes and audioble changes with going with straight throughs?



what kind of sensors are connected/associated with the CAT system? If there is one, how does one by-pass it avoiding warning lights and what not?



Any info, is of course, greatly appreciated :beer:

[m3f_99DakarM3_146594ecf1]

How in the hell do you have that list of cars man. Will you adopt me, PLEASE????





Anyway - I dont think losing the cats will get you much out of that car. AA has O2 simulators if you go with a full straight through system, but not sure what all is required on your car.

[m3f_BarryMcCockiner]

Wassup Klint. I agree, good list of cars, I guess I should head out to your side of the world, but English food makes me :bs: all over the place.

In terms of a straight through CAT, you are looking at a lot more noise, more audible backfires, and a boatload more interior noise. But, you'll get some more horsepower out of it, and if you like pissing off the area and enjoy the louder sound, the M50TU is a good sounding engine out the back.

I'm not sure if the M50TU has a post CAT 02 sensor, but if it does you will need to get a simulator as said, or find a way to give the computer the right voltage from that sensor, or the check engine light will stay on. Also, I dont know how the law works in merry old England, but out in the US we cant touch emissions equipment like the CAT unless it is CARB legal, and most wont pass smog checks with a straight through CAT.

Hit me up on AIM, I'm tired of typing now.

:beer:

[m3f_custom_6b7ab27928]

My advice is to buy a new car! Seems kinda funny that a 17 y/o would have that long list of the world's best cars and a ten year old BMW with CAT problems. Just stop driving it.

[m3f_M3AN_5f4dc0ba80]

:rockband:



What does "other rides" mean? Are they yours?



I thought I knew all of the other MF1 owners, and I don't know you do I?



Good to see you like the rugby as well. Go the AB's!!

[m3f_KidCorrado]

:hmm: I dont know about that list of cars there...

[m3f_95RogueM3]

most of that clearly is false...he doesnt even mention the 94 325 in his list, though it is a common stable-mate of murcielago's and carrera gt's.



I think replacing the cat is the best bet although it will be $499 from www.bavauto.com



I dont see the use in having to deal with the smell and the headaches involved with both driving the de-catted car as well as the headaches associated with inspections.



-RIchard

[m3f_Klint_c491bc5f79]

Thanks guys, for the suggestions, I'll check them out.



Of course the list is fake. D'oh, no harm in wishful thinking though.

[m3f_chemicals_b2f60131b9]

That car list is quite amusing.



In Aust we have these substrate cats, from the cat co, Ill see if I can find a link. They are more compact, have bugger all resistance to flow, and can cope with a better range of mixtures of A/F ratio.



Isle of man = no speed limit = fun. There is lots of pain with our shitty 110km/h (68mph)

[m3f_toopercentmlk]

cant you simply get a respectable muffler shop to make you a race pipe section, or watever its called. wouldnt it be the same as getting a similar yet prettier pipe that is made for the car by a bmw tuner? wat differences are there, because i was considering it.