How do I eliminate boost spike

[buickrob]

When I have my boost set at 18psi it will hit 22psi for about 2-3 seconds. How can I eliminate this boost spike? Should I use a blow off valve? Does a racegate get rid of this problem? Any info would be great. Thanks guys

 

[strikeeagle]

Did you open up the hole in the turbo cover? To what diameter?

 

[buickrob]

Turbo cover? I dunno What is it?

 

[strikeeagle]

Well, the wastegate is actually a round hole cut into the turbine cover or housing. The factory hole is pretty small. Once you start hot rodding these cars it's too small to pass sufficient additional exhaust flow in a controlled fashion to keep boost under control - hence a boost "spike".

So what I'm asking is, do you know how big the hole is? If the hole is big enough then we can move on to other possible problems, like boost lines and wastegate solenoids and chips and the like...

 

[buickrob]

ahhhhh, I see Its the puck in the exhaust elbow. Well that is the stock size and the hole has not been enlarged. Should I get a ported elbow with a bigger puck? If that worked it would be great!

 

[strikeeagle]

Well, opening up the wastegate hole in the turbine cover and adding a matching ported elbow with a larger puck isn't a bad idea...

You might try one other thing first. Do you know how to hook up the wastegate "tuner style"? Well, here you go:

Remove the stock boost line (the black vacuum tubing with plastic elbow and Y fittings) from the brass fitting on the compressor cover and the nipple on the wastegate actuator.

Leave the boost line connected to the wastegate solenoid, and leave the solenoid plugged in. Just tie the boost line up out of the way for now.

Run a new piece of good quality vacuum tubing (I think it's 7/32", you'll need maybe a foot of it, from Pep Boys, for example) from the fitting on the compressor cover directly to the wastegate actuator. Put zip ties on both ends so it doesn't come loose (kaboom).

See if this helps...