3" Straight pipes and boost creep question

[v01dy]

I've been doing a search and I can't seem to find the exact information that I need.

I've been hearing that a 3" turboback would cause boost creep in smaller turbos because the downpipe would flow better than the wastegate manifold. Will this definitely happen to all small turbos? I have a stock T-25 right now and am looking to put in a HKS 75mm turboback exhaust before I upgrade the turbo.

I've spoken to my friend who owns a workshop (probably the only decent imports workshop in Auburn, AL) locally and he claims that putting on the exhaust should not cause my turbo to experience boost creep.

I know how you're supposed to port your wastegate housing to reduce boost creep, but what I really want to know is if my T-25 will creep once I put in the hks turboback. I want the exhaust for the exhaust note right now and am not looking to replace the turbo for another year or so.

Please help!

Thanks in advance.

Edit: Also, is it possible to bolt on part of a turboback to the cat so that it's a catback?

 

[my98gsx]

Currently in my car i upgraded my T-25 to a 14B off of a 1st gen eclipse ( which is also fairly small ) BUT... the 3'' down pipe is not the way to go. I have a friend that has a talon that runs 12.6 in the quarter and he told me to run a 2.5'' like he does and i didnt listen, and im sorry i didnt... I have a tubular exhaust manifold, ported o2 housing, 3'' down pipe and a 3'' apexi exhaust ( with the stock cat in place ) and even with my boost cont all the way down when im in a hard exeleration my car hits near 20psi! its a big problem that im trying to fix, consatntly hitting fuel cut sucks! the car will boost to 10lbs, then shoot up arround 5 grand and it wont stop untill the car shuts its self down... take my advice 3'' cat back with a 2.5'' down pipe youll be much happier

 

[ChicksDigBoost]

Do the proper porting of the wastegate area in the turbo and port your O2 housing and you won't have any problems. I ran full 3" on my 16g and didn't have any problems.

 

[MyBeatGSX]

As oldman said many times, running a smaller more restrictive exhuast to control creep is a waste. There's a reason it controls creep... backpressure... and lots of it.

Just a side note... how is it that people hit fuel cut at 17, 18, 19, or 20psi on a 14b when I don't hit it on 25psi with a 16G? There must be a bigger problem with their cars.

That T25 can't even make much boost to begin with. I wouldn't worry about it, it will bleed down by redline anyway, negating the effect of any creep.

 

[-DSM2NR-]

No, you won't get boost creep with a 3" catback on a T25. I'm running a 3" turboback and I don't have any problems.

 

[v01dy]

No, you won't get boost creep with a 3" catback on a T25. I'm running a 3" turboback and I don't have any problems.

I'm planning to run a 3" turboback.

I'm confused... there seems to be mixed opinions over whether it would creep or not... any others wanna chip in?

 

[boostedinaz]

It's going to be different from car to car. Just because someone said it won't doesn't mean it won't. The only way to find out for sure is to put the exhaust on an see what happens. If it does creep do a search on how to fix it and itwill show you the proper way. There is no rule that will give you a definite answer.

I will agree that adding back pressure to "cure" boost creep is just stupid and should not be done.