i'm sure i'll get flamed for this but here's me dilemma. I'm undecided what to do about my exhaust system, it's already decided to go with the rb dual tip and i was deciding whether or not to replace the cat with a high flow to free up some extra power. i did search but i don't feel satisfied with what i read so i want to ask. will i have enough boost creep by decreased backflow to warrant splurging on a pfc, and if i have to go that route i might as well just get a mid pipe and say the hell with it. i currently have an m2 dp, efini y, and your run of the mill hks intake. i have a boost gauge so i can monitor if there's any spikes. also would a boost controller help the issue as well. i already have one in the car but it's disconnected and i would probably just buy a new one if necessity required it. Thanks for the input,

-Joe

 

No you will NOT creep with a hi-flow cat. You will likely have elevated boost though, that will require a boost controller to lower back to stock 10 psi. You will not need a PFC. And just because you have a PFC doesn't mean you can run a midpipe....

 

that clarifies things a whole lot, thanks

 

Joe,
Boost CREEP is different than SPIKE and caused by exhaust that flows too efficiently for the wastegate to handle. Generally it can only be corrected by two methods, porting the wastegate or adding some back-pressure back into the equation....ala a hi flow cat. A mid-pipe also carries some other issues that may or may not bother you. It's louder and tends to smell. I believe Jon, (fitzrx7) runs a midpipe. When he gets his car back out, you'll get an idea of what it's like.
Even with a hi-flow cat, with your mods you will probably see some SPIKE. I have similar mods and saw spike, especially w/ ambient below 60 to 65 F. Unlike creep, SPIKE can be handled by a BC, either electrical or manual. With a lot of help from Jon last fall, I installed a manual BC and pre-spool and run rock solid 10-8-10. Got about $10 in it.
Also, if you replace the stock cat, IMO don't go cheap. I have a BONEZ and am very happy. There are also a couple of others, but do a search for track records.

 

Adam C said he bored out his stock cat and had it re welded on the outside for more power. Just thought I'd throw that out while you're thinking of replacing the cat.

 

got it, thanks jim. for some reason i thought a creep was a precursor to a spike.

 

Hi joe!

Nice choice on the RB Dual tip, that's what I'd run if I had the money.

A boost controller will only limit as much boost as your wastegate can handle. Meaning no matter what you set it to, if you are flowing too much, it's going to over boost.

 

Yes, that's called creep and it won't happen with the hi-flow cat in there.

 

Yes I know that, I just didn't want him to think a boost controller will solve that.