Let me start by saying, I have no way at the moment to monitor knock. That being said....

I'm trying to get my boost set to 22psi, I have a turboXs MBC, and when I set it up, I'll floor the car in say...4th gear at 3500rpm....my boost will spike to say...24ish and VERY quickly drop off. Am I really boosting 24psi at that time? If so I think that kind of defeats the purpose of a MBC.

If I slowly accelerate my boost will steadily climb to 22psi and won't spike up to 24. I don't think I've heard any knock, though I've heard if you actually hear the motor knock it's already too late for your pistons!

I will, within the next few months get some way to monitor my engine better, but for now I want to go fast, but I don't want to ruin it either =p

Any help will be appreciated, and if this has been covered, I appologize I didn't even attempt to search....I didn't even know what key words to use.

 

Is it the regular mbc or the HPmbc? I know with the Hpmbc, you have more room to adjust. This really helps with spikes. I had an issue similar to yours after cam installs. Playing and adjust the HPmbc fixed it. With the regular mbc, theres not much to do but turn it down a little. Do you have your mbc hooked up to the actuator and turbo?

 

Regular MBC hooked up to the actuator and the turbo. Sucky, I really don't want to turn it down =/

 

also remember that the boost controller, MBC, solenoid, or otherwise... is only part of the boost controlling system.

the next thing to look at when trying to nail a certain spool characteristic is the wastegate.

for me I notice the worst spike during powering up off an on-ramp... kind of like you but i'm doing it in 3rd not 4th.