Over Boosting? Need some help guys

[Halon]

Yes, perhaps your tapped compressor housing job is no good. Try a different boost source.

[talonsway]

alright ill go to the intake manifold for the boost source and ill plug the compressor housing hole. Ill let you guys know how it goes!!

[Shane@DBPerformance]

There is more boost at the turbo than at the intake manifold, so going turbo can help lower the boost. But intake manifold is more consistent for changing conditions and better for holding higher boost. Sometimes a boost source right on the turbo does not work though. But its a 16G on a DSM aka guaranteed boost creep. Usually it just creeps to like 21psi though.

[talonsway]

well I wanted to hold 15 maybe 20 pounds. So if I could get it to hold around there I would be happy. Might just start saving for a external waste gate set up, just drive it like it is because I can not figure out why this is happen. My friends DSM with his 16g and he only boost like 12 and it holds perfect

[1990GSX]

To rule out boost creep, you could unhook the wastegate flapper so it's open all the time, and see what your max boost at redline is.

Did you try this yet? If it still creeping that means your not able to vent off enough exhaust fumes through the wastegate exit to keep the compressor from still building boost.

This would eliminate both the mbc as the source and the wastegate.

[Halon]

You cannot figure out why? Have u tried the 2 tests that were mentioned?

[talonsway]

If I unhook the wastegate arm to the flapper it wud just be closed ? It wudnt stay open. I took the arm off to see if it was stuck. And it moves free but is this what I should do just take the arm off so it's open when I boost ?

[Halon]

Yes. You unhook the WG flapper and force the flapper so its just open, that way you forced it to bypass as much air as it can all the time. So your boost should be as low as it physically can be. Then you see if its still over boosting. If it is, then you know the issue is the wastegate just physically cant do any better and is your limiting factor. if the over boosting goes away, then you know the wg itself is not the issue and for some reason its just not getting told to open because you just proved that if its open it was nt overboosting, which is then why you try another boost source because perhaps there is some unforseen issue with the spot you are using now.

[talonsway]

Thank you guys a lot I'll let you guys know what happens !

[talonsway]

so i removed the arm and took it for a drive, at about 4-5k i was seeing about 20 pounds of boost and at about 6/6.5 almost 30 pounds of boost. So if i am thinking right this means i found the problem, and that is that my waste gate is bad? So start shopping for a big 16g Waste gate actuator?