I took my cat out and replaced it with a manufactured bolt on Flowmaster 12" muffler. From the cat back I am running a straight pipe with a dual Ansa tip. I am also running a SS downpipe. I had my car on the dyno with an o2 wideband. I am running a PFS ecu. I found it was running way too rich--that's why the smell was so bad. The sound increase is higher but not too high. I get great response down low because it is alittle more restrictive than a midpipe. When I have to go thru emissions, I just unbolt and bolt the cat back in (1 hour). I'm running 13 PSI boost, and get about 264 rwhp= 318 hp. But I'm still looking for more!

 

What do all you midpipe people do when emissions tests come up? Do you have a garage and change out parts yourself or get them done somewhere? I know there's no way you can pass emissions with a midpipe.

 

On my friends 94 we're running stock motor, stock turbos in stock sequential mode with Blitz FMIC, homegrown intake, DP, Random Tech HF-Cat and N1 exhaust. Air pump and all still running to the cat, with an APEXi PFC set at 12 psi. Ran a 12.84 @110 on Kumho Supra 712s spinning like mad. And it's still pretty damn loud too...

It breaks the tires loose when hitting the second turbo as well. IMHO I think it runs okay.

 

My friend owns a smog shop and he passed me for free.

 

Yup...they sure will. I would go with the midpipe. I have one and I love it. I drag my car all the time, and I don't notice any problems. The high flow cat is good too though. I would say that cutom tailor it to your specs.