My 944 turbo is basically stock except for Autothority Stage II Chips and a K&N Air filter. I also replaced my stock muffler with a Cat back 3.0" Fabspeed several weeks ago because my OEM was corroded in 3 different places. The exhaust sounds fantastic and I was thinking of going ahead and purchasing the rest of the set which would be the cat bypass pipe.

Hypothetically speaking, if I lived in California I would be in a tricky situation -If I made the purchase, every 2 years I would have to put the cat back on for smog.

What kind of bump up in horsepower, torque and throttle response would I get from this addition and just how loud would it be? What about any resonance inside the cabin? I've heard Fabspeed's demo of loudness on their website, but I'm looking for further input.

Thanks again

 

Getting rid of the cat is worth 25 hp. I have proven this on the dyno. It doesn't matter if it is a 2.5" or a 3" pipe, the big concern is that the cat goes bye bye. Actually on a stock car or fairly stock car, a 3.0" exhaust only makes about 4hp and 7tq over a stock 2.5" exhaust (both catless). Once you start talking bigger turbos, then the bigger exhaust becomes more beneficial.

I have the full fabspeed system 3" on my 951 (including the downpipe off the turbo), and it sounds fantastic. Not overly loud, and no resonance. The sound clip on their website doesn't do the exhaust justice in my opinion. Actually for the track sometimes I wish it was a little louder. Around town is fantastic.

 

Very helpful Doc - Thank you. I may be taking that plunge pretty soon then

 

My 951 had a custom straight (no cat) exhaust on it when I got it. I had to install a cat to pass Colorado emmisions. The cat totally killed the car. Took all the fun out of it. Spools slow, throttle response is down, exhaust is quiet.

Cat is coming back off as soon as I get time to fab up a "test pipe".

 

Yeah Cole,

That will be my issue as well. Every two years the cat will have to go back on for several hours

 

Worth every penny!!!!!!!!!!!!!!!

 

definitely worth the dough