what causes boost spikes?

[ANVIL]

so after i went to the track last (13.2@106 again, but got a 13.4@108) wednesday i noticed i get some boost spikes now. not sure what it is. its like if im in 4th gear going like 45ish, and i floor it boost will go to like 13.7 or 13.0. my ebc is set to 12. i checked the vacuum lines on the ebc, and my couplings are all good. im not sure what else to check.

[BoostFab]

if the boost climb to 13.7psi then settle back down to 12psi, then you are probably experiencing "boost spike". but on the other hand if your boost stay up at 13.7psi then you are experiencing "boost creep". if boost creep is the case, then your wastegate is not flowing fast enough to bypass the exhaust gas. now if boost spike occurs, either your source lines are too long or too small and it cause a delay to and from the boost controller.

[ANVIL]

sounds like im having boost creep then. could my wg on my stock turbo be going bad? or is it that i just cant handle it?

[Darius]

You can also get boost spikes if the gain on the electronic boost controller is set too high.

If you're only running 12 psi, the stock wastegate should be able to handle it. I ran 12 psi solid all day long when I had the stocker on there and never had it creep.

What exhaust are you running?

[ANVIL]

3" down pipe and 3" straight piping to an n1 style turbo muffler.

weird cuz it never did this before. i might have accidentally changed the gain. ill check that. what should it be if i want to be on 12psi? im still a noob to my blitz ebc.

[Darius]

You have to play around with it until it doesn't spike and is a linear increase. I think for that level of boost, it should be in the neighborhood of 50-70. Keep decreasing it until it no longer spikes and see if it is helping at all. Rule of thumb is to test the free things first.