What causes boost creep??

[vettekiller]

What causes boost creep?

 

[Niknuk]

When your turbo wastegate can't bleed off enough exhaust gasses from hitting the turbo, causing it to spin faster and faster, producing more boost, even though the wastegate is all the way open. Hence, your boost creeps up w/no way to stop it unless you let off the throttle.

 

[larryd]

you can prevent it though by porting the o2 housing..

 

[GRNDSM]

People already mentioned the causes for boost creep, but have some additional ideas behind it…

Boost creep is a double-edged sword… It can be a sign of a well tuned engine and it can also destroy your engine .

If you take non-ported 14B or 16G and put it on a 1G with free flowing exhaust w/test pipe (like BR 2.5” or better), you should see boost creep. If you do not, then you have problems. If you port your turbo, O2 housing (and do it right), adjust your WG actuator to proper pre-load and you still have boost creep (past 18-19psi), then your car is running really well and you must start considering a larger flapper valve. Usually, that does the trick for most people, but if you are still having some boost creep, even with the larger flapper, your two choices are to live with it or go to and external WG.

BTW the best way of dealing with boost creep to 18-19psi is to set you boost to 18-19psi. This way you will never see any boost creep . I have had it this way for over 4 years now. You just have to make sure that you have enough, good quality fuel to deal with that extra boost.

I was using 1G example because you have a 1g and because boost creep is worse on 2g’s. I think that is because of more restrictive intake system (head/intake/TB), which makes it easier to build boost (good for boost lag, bad for boost creep). So my rule of thumb is not as applicable to 2Gs because even poorly tuned 2G tend to creep