MelloYellow

Stay with Hi-Flows for some backpressure to spool, or ditch the cats?

Thinkin'..

smokinHawk

iTrader: (48)

If you dont got emisions yank them out.
back pressure slows spool.

Mark C

I think that people overestimate the power loss from cats.

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.

AlienDroid

you can hook up cats in parallel, so theoretically you could have as many as you can engineer. The more cats the less backpressure and the better emission quality in my opinion.

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" />

smokinHawk

iTrader: (48)

9 hp is 9 hp some want all we can get, cause every little bit helps.