Cats or No-Cats for a Turbo?
My Incon kit was installed with the offroad pipes. I later got the cat Y-pipe and put it on. I dynoed both ways without any other changes between runs. I don't have the numbers in front of me, but I lost either 8 or 9 rwhp. I think it went from 434 to 425.
Even if I did not have to pass emissions, I would run the cats. For 9 hp, the car stank.
On my single turbo setup I'm going to eventually have (once emissions become a concern for me again) two cats in parallel from the exhaust pipe comeing from the turbo and another cat from a separate pipe for the wastegate that dumps into the exhaust downstream. This is just speculation at this point.
Of corse it takes lots of custom work. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />


