the sh*t just hit the fan

[MPNick]

I wasn't saying the internal gate was at fault, I was suggesting maybe the DP was too restrictive at the wastegate port.

If the DP was too restrictive the boost would build very slow and lower not higher.

 

[BradC]

If the DP was too restrictive the boost would build very slow and lower not higher.

Gotcha, I was misinformed then. The way I understood it was if there was too much turbulence when the wastegate swing opened, you would get creep.

 

[yellerandahalf]

it almost makes sense, i agree. but practical experience, and reading "Maximum Boost" tell me otherwise.
-Mateo

 

[AzMz3]

Boost creep can be caused by a free flowing exhaust and intake. It is a known problem on subbies. You usually have to port and enlarger the wastegate wheel. I have seen some even port the down pipe to help with the exhaust escape the wastegate better.

A restrictive downpipe would cause less ceep than a free flowing one.

But the common fix is either to bore the wastegate or go to an external wg.

 

[yellerandahalf]

well, that's...almost correct. We see creep all the time with FD's as well. The free-flowing intake and exhuast dont' directly lead to creep, but indirectly they do. They make the engine flow better, making more power, and exhaust gas energy. After a certain point (high-flow intake, exhaust, 15psi on FD's), the wastegate no longer has the capability to divert enough exhuast gas energy to keep the boost from creeping.
-mateo

 

[AzMz3]

well, that's...almost correct. We see creep all the time with FD's as well. The free-flowing intake and exhuast dont' directly lead to creep, but indirectly they do. They make the engine flow better, making more power, and exhaust gas energy. After a certain point (high-flow intake, exhaust, 15psi on FD's), the wastegate no longer has the capability to divert enough exhuast gas energy to keep the boost from creeping.
-mateo

I think you just said the same thing I did...so either you are almost correct or we both ar correct! (poke)

 

[yellerandahalf]

works for me! just attempting to clarify, and make sure everyone was on the same page!
-Mateo