chris2k03

Boost is set at 14-15psi right now w/ boost cut set at 18psi. I keep hitting boost cut in 3rd/4th gear. Would it be safe to set the cut to 19-20psi?

Details to my setup in sig. Thanks.

DFWs2k

Yea, before checking wastegate lines, raise boostcut level. Your car just wants to go faster.

camuman

Who tuned it? Why is it creeping 4 psi in high load gears?

Raising the boost cut doesn't fix the problem.

TonysMI4

Can you even run 18 psi on a stock motor with a log mani? Im sure thats not safe at all.

Deception

Its ALIVEE!

chris2k03

I forgot to mention this happens at wot. Isn't that boost spike and not boost creep?

passmans2kny

sounds dangerous, ge that fixed asap b4 u blow up u motor

chris2k03

Emailed my tuner and he mentioned my setup is just a recipe for spike.

"The issue with the combo is boost spike....the car runs at 14-15 psi when past spool (practically 4500+rpm).

Boost spike depending on load kicks it up a couple psi at spool. Small turbine housing, loggish mani, small wastegate.....massive breathing f20c engine = recipe for boost spike."

Spoolin

It may just be that you could be running too small of a wastegate like a 38mm instead of a 44mm and you are experiencing a boost spike before the wastegate is able to control the pressure. Try raising the wastegate duty cycle on the boost solenoid in the AEM, if thats what you're using to control boost. This may help it a bit to overcome the slow responses. Otherwise and if that doesnt work, it may be best to upgrade to a larger wastegate. I'm sure this is the main culprit of the spike.

riceball777

i am running the same exact setup as you almost. I run a rev hard log manifold with a ball bearing garrett/precision 50 trim on a tial 38mm wategate. i run 9 psi on 91 octane 14 psi on race gas. The boost is always rock solid at where it supose to be.

my setup with pics with a dyno chart and boost plot is in my signature.