tegman23

Hey guys I was just wondering if somone could help me out. My daily driver is a 91 crx si sohc turbo, it just has a greddy kit on it running off the wastegate...My question is I tried putting my turbo xs boost controller on it just for a little more fun...On my integra with an external wastegate, when I used this it was just routed in between the wastegate and turbo housing..

Now my question is I tried to do this on my crx and its just spiking 10psi then comes back down to 6psi (wastegate setting) and stays there...Can you not use a boost controller on internal gated setups or ? thanks for the help guys this is my first internal setup, all my other setups are/were external..

accord_raffi

A boost controller should work on either type of wastegates the same. Is this an old mbc? Maybe the spring inside is faulty or the bleed "hole" is messed up...

tegman23

No its pretty new turbo xs manual boost controller, I had it on my 370whp teg until I got my gm boost by gear setup...I know it works for sure..I just dont understand why its spiking 10psi then coming back down to the wastegate, I thought it would work for sure as well..

accord_raffi

Is it between the compressor and the wastegate or between the IM and the wastegate? If the boost source is the turbo, maybe you have some significant pressure drop which would be odd since it's just a greddy kit. If you haven't already, check your vacuum lines. Whichever you have it at, try running it the from the opposite source. Are you trying to boost 10psi? If not what level?

tegman23

I have it going from the compressor to the wastegate, all the vacum lines seem fine. I just want to bring it up 2-3 psi just for a little more fun, I never had any problems with my external wastegates but, I just cant figure this out..

accord_raffi

My friend uses an mbc on his saab and it works fine. Try using the intake manifold as a boost source...maybe it's a pressure drop issue?

blaze the chemi

I had a greddy profec B setup between the wastegate in intake manifold on my greddy kit. The turbo didn't come with a barb for it's pressure source.

HiProfile

Internal WG actuators already bleed boost in most cases, so that extra bleed hole on the MBC should be covered up. If its a very small FMIC and u use boost from the turbo, not manifold, its slightly possible that's the cause - but 4psi loss is a lot.

Have you tried it w/o the MBC? Does it stay at 6psi normally?

tegman23

Ill try using the intake manifold tonight as my vacum point...

yes I have been driving the car for a while just on the wastegate, always just went to 6psi and stayed, now with the mbc its spikes 10psi then comes down to 6psi off the gate..Its weird you can here it spool go up to 10psi then comes back down and the wastegate opens..Im going to my girlfriends house ill switch the vacum source quick before I leave