hey guys. I would like to thank you guys for the responses as the threads got many. I guess a dual exhaust setup is really not worth it for the mods that need to be made. I was looking and just don't seem to see the clearance for the full exhaust. My 323i is restricted like crazy. they restricted my whole exhaust system my headers my air box my computer my intake manifold & im sure other crap as well. I've changed my headers and they actually close off the outlet with a little indentation in the headers themselves to restrict air flow. I've changed my headers exhaust and made a dual ram air setup & it does 0-60 in around 5.6 which is the best time I've got so . (and it is an automatic)As for the 328-m3 exhaust swap im not really sure if I can put dual pipes all the way from the headers back to my exhaust. I just have a single cat & no resonator. I don't think it will fit but I guess you don't know until you try. I don't understand why they also detuned my car from the factory. The 325 has the same motor & I believe less restrictive. I believe the 328-m3 exhaust will be much better even though form this thread you guys say its smaller. I just don't know how 2 cats are going to fit under my car. But I could be wrong I don't know if anyone's ever done this before? or even m50 intake manifold swap for more power? and my car is a OBD2 not OBD1 to whoever stated above. thanks
Last edited by agoliver2; 02-15-2013 at 04:47 PM.