I have the stereotypical boost spike scenereo....2nd gear WOT at about 4500rpm only very cold days I see a quick spike to 15psi before stabilizing at 11-12 up to redline. It is very repeatable. Related mods include downpipe, XS ecu, intake, 3" exhaust with high-flow cat, K&N, Stage II street port.

I don't think this is a wastegate problem since it does stabilize after the quick spike.

With a stock fuel system 15psi certainly concerns me. I've been reading about all the potential solutions...Home Depot mod, pills, pop-off valve, porting wastegate, restrictor plates, etc...but there doesn't seem to be a definitive answer. It seems like most of the mods change the total boost in order to reduce the spike, which really isn't what I'm after. I'm intimidated by the Home Depot solution with all its tuning and complexity. Any recommendations? Has anyone successfully fixed this problem? I had been considering the PFC, would it help?

Thanks in advance for any feedback!

 

I had the same problem. I made a plate with a smaller diameter hole than the exhaust system. Using a 3" exh., you could try a 2.5" hole & see how that works. My spike is gone, but I'm sure at the expense of some top end power.

 

Profec B boost controller
I also had spikes to 15+ lbs.on transition and after the elec controller all was well...

 

Thanks for the input. Couple more questions...

First, would I be correct that if I put in larger injectors and upgraded fuel pump along with a PFC, the spikes wouldn't matter anymore? It's not going to hurt the turbo if it just spikes for like a tenth of a second is it? The only danger's running too lean, correct?

Secondly, I'd still be interested if anyone has a PFC knows whether it will tune this out or not. I know there's lots of turbo settings in it, and I hate to artificially restrict my exhaust or buy more electronics if it'll take care of it. I think it's a pretty sure thing in the next couple of months...

Thanks again

 

Port the wastegate!

 

I thought ported the wastegate will only solve the creeping problems not spiking.

 

Change out the pills in your turbo control hose for larger pills.

GEB.