I have a 88 vert and I unbolt the old mufflers and just cut the pain in the *** heat sheilds off and weld on two 2 1/2" free flow mufflers. What I hear from some people is that if you remove all your cat, etc. then your car will run alot more powerful. Then I hear from other people that it will make it lose power. Could I remove them with or without losing power? I don't have to worry about emissions test, I live in Florida and only like 5 counties test cars for that crap. If someone could tell me what really would happen if i took them off I'd really appreciate it.

 

well if i remeber correctly the s4 5th 6th ports work off of the back pressure from the exaust. so if you don't have enough back pressure then you wont be able to open you 5\6th ports properly. look also for air pump removal and that will tell you some more.

 

it has to do with the differences between turbo and na

turbo it will increase your boost and the na will not have enough back pressure to open your 5&6 ports losing power up top. If it's clogged almost anything you will do will increase power.

I reccommend keep'n a high flow cat even with a turbo.

Search around some more for more answers

 

Do you think if I removed all, and put smaller pipe, I'd keep enough backpressure? It is na too.

 

get a racing beat presilencer. it wont be as much of a ghetto rig, will open the aux ports, and will keep your ears from bleeding of the N/A exhaust. trust me. mufflers alone are not enough unless you want to damage your hearing and irritate the hell out of everyone you drive by.

 

I so get this presilencer and take off all my old crap and weld it on with all new pipe same size? This will let my ports open.

 

im not N/A guy but ive read that theres a way to wire the 5th/6th ports open so you dont have to worry about this problem. I dont know and advantages or disadvantages. Might want to look into that. oh yea, i have strieght piped turbo2 and i regret stright piping it. Its stupid how loud it is. Im guessings its atleast got 120+ dB, my left ear hurts after a long drive in the thing. I def have to get an RB presilencer. I cant even emagine how loud and N/A would be because of the absence of the turbo.

 

Wired open you lose low end. Your best bet is to just buy an exhaust system thats designed to provide the proper back pressure

 

I have a 88 gxl with a race pipe, and you gain a crap load of high end power. but you lose low end torque cause your 5th and 6th ports wont work correctly. Mine were modified before i bought the car so I said why not go with a race pipe, I can tell there theres not much low end though and it does make you car alot louder so you know. I would suggest a high flo cat. Matt22

 

ah....yeah i got it backwards (i dont' own a na)

 

i have the dynomax cat-back system with the racing beat header and straight pipe, which has the thingy for the back pressure!! i gain very noticable power with that setup!! no problems either!!

 

what im going to do is get a RB collected header and from there go into a Y pipe that goes to 2 RP 50mm catback mufflers, i heard this setup and it sounded great... i have a S4 n/a too so i think it will provide adequate backpressure... anybody feel free to offer an opinion...

christopher

 

Basically just get the RB header, and a high flow cat. If it is still too loud, get a pre silencer. For everything else on the car, get whatever you want.

 

you're in florida, don't get a high flow cat. you don't need it unless you actually *care* about emissions. get a header, and presilencer that has the back pressure bung in it. the presilencer is straight-through, so it's not much of a restriction at all, and your aux. ports will work fine. I love Florida!

 

cool, thanks man