boost spike ?

[ka-t 300]

what is boost spike ? any way when i first hit full boost my boost gauge goes 1-2 # over the set pressure then comes right back down to the set pressure and holds stesdy boost at the specified pressure. is this ok ?? or normal ? it started doing this after i instaled a manual boost controller . i have a tial 38mm waste gate open dump with a 6# spring running 9# of boost..

[lrb_2000]

Where are you getting your vacuum source for you wastegate from?

[ka-t 300]

the boost source is comming off the turbo for the waste gate . the vacum / boost source for the boost gauge is off the line that runs between intake mani and brake booster.

[ka-t 300]

there is another coming off the bottom of the waste gate that is just open to the atmosphere. should that be hooked to a vacum / boost source i was told it was ok to let it vent to the atmosphere.

[480sx]

Leave it VTA, unless you have an electronic boost controller. It could be your manifold's 38 mm wastegate flange/tube doesnt adequately move gas around from the turbine at those low boost levels. It doesnt sound like its to bad, but if you turn up the boost a few pounds your spike will probably go away.

[Florida240sx]

Mine did that too. Partially because of of your MBC. My t3/t4 would hit boost hard so it had a slight spike for a 1/4 of a second. I enjoyed it