I have a greddy sp2 on order from southwest and a budget-y on order as well. I'll be hacking my airbox in April. I couldn't find an answer to this question in the FAQ so apologies in advance if it's in another sticky.

Does a high-flow cat like that by Random or the magnaflow available on redline make any kind of a performance diff on a max equipped with a y-pipe and catback exhaust? I'm not expecting much if it does, something like 3-4hp I'm guessing, just wondering if it does anything at all.

Thanks.

 

Yes, high-flow cats are pretty worthless and most take a dump after sometime (notably RT cats so i hear). Im just gonna run a bolt-on straight pipe when i go to the track and swap the converter back in for street use. The gains are VERY minimal...1-3hp id presume...But hey, something is something




Eric

 

Yeah, you will be doing good to get 1 hp out of a high flow cat. You might as well just spend $50 or so and get a muffler shop to custom build you some 2.5" b-piping all the way back to your muffler. This will add more than the high flow cat would(5-6hp)

I would leave stock cat on and stock resonator, unless you want it really loud. That is what I have with a Warpspeed y-pipe, and a 5th gen muffler, and it sounds good, but not really loud.

 

I doubt it only adds 1hp.




Eric

 

damn, that's it? I was hoping with a y-pipe and catback exhaust that a high-flo cat converter would add more than 1-2hp.