G-valve: Does it have limits?

[Dave]

I took my 20's out of the Spirit and swapped the entire rail assy. and dumped it into the Acclaim (can't use those injectors anymore, anyways). Whole purpose is to turn up the boost.

It has a G-valve on it, so I start turning up the boost, hair by hair. Pretty soon the valve is at it's shortest length, and it will not shorten anymore. 16psi is all I got out of it. :confused:

Have I hit the G-valve's limit? I've never pissed with one of this before, I always used my HP MBC.

-Bryan

[Frank]

Yes... see the FAQ section up top for a spring upgrade.

[MiniMopar]

Actually, if the valve is all the way in (with the locknut removed), it's not the G-valve.

[contraption22]

Yeah you should be able to get about 20-22psi out of the G-valve.

[MiniMopar]

Well, I guess there could be some junk on the ball seat that is making it leak if you have indeed screwed it all the way in. If you still have overboost cutout, you can just unplug the wastegate can to see if you can build more boost. If you can, then the G-valve is the problem. If you can't, then you problem is elsewhere (weak wastegate spring, plugged exhaust, etc).

[GLHS592]

Leaky BOV or weak WG can?

[Dave]

Well I installed the MBC out of my Spirit and I got only 1psi less max limit. So now I'm only getting 15psi with this MBC, as opposed to 16psi with the G-valve. I'm gonna take apart the G-valve and HP P. MBCs and see if there's any problems with both.

For easy troubleshooting I'm gonna stick with the HP P. MBC, as it's just a lock nut/bolt design, real simple. If I can't get more than 15psi I'm going to shim the WG can a little.

[slasky]

Mine maxed out at 20 psi with the locknut removed and the spring stretched a little.

[contraption22]

Well I installed the MBC out of my Spirit and I got only 1psi less max limit. So now I'm only getting 15psi with this MBC, as opposed to 16psi with the G-valve. I'm gonna take apart the G-valve and HP P. MBCs and see if there's any problems with both.

For easy troubleshooting I'm gonna stick with the HP P. MBC, as it's just a lock nut/bolt design, real simple. If I can't get more than 15psi I'm going to shim the WG can a little.


After trying both boost controllers, aren't ya starting to think that maybe it's something else limiting your boost?

[Dave]

I really do think the WG can is weak. But I found it weird how the G-valve got one more psi than the HP Performance. Hence me asking about it.

[contraption22]

Both of those boost controllers should have capability over 20psi. You another problem with your setup. I would do a pressure test on your turbo plumbing to make sure all is well.

[Dave]

Well I took the lock nut off the G-valve, I got it to 17psi. But it's real inconsistent now. I had 17psi now all of a sudden it's at 15psi. :confused: The weather has stayed the same too. It was between a 3 hour period.

I might have a boost leak or the can is fubar. I'm gonna tighten the BOV spring a bit and see what that does.