I want to upgrade to an aftermarket exhaust, but I'm very apprehensive because of "boost creep stories" that I've heard. I've heard this is prone to happening with the Turbo-back exhausts, but not the Cat-backs.

Would it be beneficial to get a Cat-back exhaust, or would I just be wasting my money?

Also, how much of a difference in power would there be from a Cat-back Vs. an Axle-back?

 

Catbacks and Axlebacks are, IMO, a waste of money. They will add the boxer rumble, but will add minimal hp (like 5-10). The limiting factors in hp are the 3 catalytic converters blocking air flow in the 2.5" pipes.

First thing should be a catless uppipe (pre-turbo), that will increase turbo spool by like 200% (get intercooler hoses too for faster spool). Then there are 2 more cats left after the turbo. A full turboback replaces ALL the piping after the turbo. You can get them catted or non-catted. You can buy a full turboback system or mix match downpipes/midpipes/catbacks/axlebacks, ect...just make sure they all fit together. Turboback and uppipe will add like 25-40 hp depending on dyno (more with EM)

You can also search, this has been covered a jillion times

 

Aren't the non-catted systems the ones that will cause boost creep? Or could a catted TBE also cause experience of boost creep?

 

Boost creep depends on which car. It's been known to happen to STi's but not all the time. A non catted TBE will net you the most power and is a wise decision if you plan to upgrade down the road. You will see the real performance happen when EM is added with a TBE. Good luck

 

Yeah, its rare for boost creep to happen on a wrx. gooder77 had some boost creep issues with a catless 4" TXS and VF34 setup, but that is rare. I have the same exhaust but with highflow cat. My boost with ecutek maxes at ~ 16.5psi, no creep. Its gone up to 18lbs, but that when it was FREEZING COLD! Car felt like a champ, so much so that my clutch started slipping

 

I'm not real worried about eeking every hp out of the car that I can get, but rather extracting reliable hp with minimal issues to worry about.