mikey D

I dont see why everyone with TII cars has this boost creep problem. It really makes no sence. I have had expiriance with s5 turbo's making quite a bit more power than stock with no boost creep.
I also know some people with s4 turbo's with no complaints either.
both were very stripped down motors though.

I wonder if it has something to do with all the mazda extra emissions and eletronic junk.



or a poor exhaust system...i did notice the waste gate is covered by the backing plate on rx7 turbos. maybe that could be modified.

Digi7ech

iTrader: (1)

What don't you get about it?
Once you open up your exhaust and intake your pulling more air in than it can push out through the gate. This makes the turbo spin up more and can over boost.

S4's have been said to really suck *** around 12psi.

I think J-rat said he's hit 15psi due to it before.

Scott 89t2

if you are making "more power then stock" then your boost is higher then stock. and therefor is mostly likly creeping...

any boost over stock is creeping... just because it's not going past what you want (say 10psi) doesn't mean it's not.

VietFC

i think someone on this board had a video of his car creeping to 20psi on his fc. I think his sn was 20psifc

gergrx7

um no it isnt 20psifc. is was fstrnyou. and yea he was running 20psi on stock IC, turbo and injectors and blew his motor up.

VietFC

oh yeah
hahah. i forgot that he also sold me a 3" RB DP. i guess i'm next for destruction.

NZConvertible

I think your definition of boost creep must be different to everyone else's. If you put a 3" exhaust and a pod filter onto an otherwise stock S4 you'll easily see over 15psi. That's boost creep. The FC's you refer too either had ported wategates to keep boost down or modified fuel systems to cope with the extra boost. If they didn't they're probably dead by now.
The emission controls have absolutely nothing to do with the turbo or boost control. Boost creep is an entirely mechanical problem caused by an undersized wastegate.
You've just described the layout of just about every internal wastegate made. Yes, this design can be improved to increase wastegate flow, but it is not a problem specific to RX-7's.