Thread: wont go past 7psi

yeah thats why im stumped on this one I have a turbo integra and bmw and none of them have had a problem like this.
Granted this is my first internal wastegate setup still i figure if you unhook everything from the diaphram and leave it wide open it would boost the hell out of the car.

but its internal wastegate how would I check and see?
I've heard of something w/ an air compressor but not too sure about the details

You can try pulling on the wastegate actuator arm by hand and see if it moves easily.
Disconnect the wastegate actuator arm from the internal wastegate, and see if there is too much slack between the actuator arm hole and the actual wastegate.


Now let me back trace a little bit.

With the Wastegate line connected directly to a boost source, you get 7 psi tops (unless it's a W11).

With the Wastegate line connected to the MBC, you are getting 8 PSI right?

Your last sentence you said you took off the MBC, and left the WG line open (no vacuum source right?). And you got 3 psi tops?

yes thats correct

I will actually try that. I remember doing that one day and the arm seemed to be loose or disconnected to the actuator not sure. but im going to try and see if that is it
also I found out that the MBC was not hooked to a direct vacuum source it was hooked to a nipple on the bottom of the throttle body hooked my boost gauge there and there was no vacuum read at all. so I hooked the MBC line to the "tee" that my boost gauge was hooked to and now I have direct vacuum to the MBC and found out there is a pin hole leak on the side of the MBC it self. Now whether I tighten it all the way down or not I still get 8 psi

also forgot to mention in the beginning.
at about 5000rpm it will start to surge like.....(sounds weird but only way I know to explain it) it seems like my turbo is hitting rev limiter or something it just stops pulling
and its when its at full boost at 5000rpm. ppl have said it feels like its trying to boost more but it can so it backs down then tries again.
I've heard that my spark plug may be gapped wrong so im going to check that out. i know its supposed to be .028 (upgrade turbo) and .032 (stock turbo) correct?

and there isnt any slack in the actuator arm just checked
went to auto zone and walmart trying to find a hand pump with a pressure gauge so that I can check the actuator by pumping it till its fully open and then checking the pressure. but had no luck on finding one

Sounds like your turbo is overboosting. You definitely have a huge boost leak.

Gapping for turbo is at most .028, depending on how much boost you run .020 might be safer.

Make your own boost leak tester. You will need a tire-stem valve from auto parts store, and a PVC cap. Drill a hole, and put the tirestem in. Mount it with t-bolt claps and silicon coupler to the turbo inlet and start pumping air via air compressor or pump.

I've checked everywhere for a boost leak and havent found any

how have you checked for boost leaks?