Boost Drop

[Waldo]

hey guys im trying to figure out a problem, im trying to run around 19 - 20psi through my high flowed turbo, but when the tuners tried to tune it for that they said that it would spike to 20psi but then drop back to around 12psi - 14psi, they said there is no leak in the intercooler piping because they would have seen a change on the dyno readout, they thought it was my actuator so i went out and bought a hks adjustable one and im using the apexi power fc boost kit. Does anybody have any idea why boost drops off that much? could the stock bov be opening up?

[MearCat]

I am curious to find out what psi does the stock start to leak and whether anyone has figured out how much it leaks as more boost is applied...

[Al]

With rb25's the stock BOV generally leaks at about 16psi. This of course is not a written rule, as with age the spring may get soft.

Why not do a run with the BOV blocked. Generally not a good idea for permanent use, but i'm sure a couple of runs on the dyno would be ok.

[RANDY]

Dude... stock BOV? I don't think it'll hold that much. Is the high-flow the stock turbo or a bigger unit? I guess what i'm asking is; what is the wastegate doing?

[Waldo]

hey mate, yeah its a high flowed stock turbo, with steel wheels but NOT ball bearing. and yes the tuner said it might be the actuator, so i bought a hks adjustable one, but it still does it...although i can get it to hit 1.5bar of boost with the hks item but it drops straight back down to around 12-14psi after it spikes.