Grainger valve, what happened here.

[jeff1234]

So I set up a grainger valve as per the dodge garage diagram. I took the car out to tune the level of boost but could get no higher than ten PSI. I thought, OK, my wastegate (large can) has a problem. I took off the grainger set up and reinstalled my wastegate line. I made a pass and my boost spiked to 15 psi and the dropped back to ten psi. What gives here?

[4 l-bodies]

How big of a bleed hole did you make in your Grainger valve? Jeff, if you have a Mityvac pressure/vacuum pump or even a regulated air source you can check approx. opening rate of a Grainger valve. In my experience with them, you can get around 18 PSI with them before you need to add/increase spring rate. It will be close to it's minimum length when they start to adjust in the 15-18 PSI range.
Todd

[ajakeski]

http://www.gusmahon.org/html/boostcontrol.htm

[jeff1234]

I've got a .030 mig welding tip in the hose, right after the intake.

[jeff1234]

I don't have the bleed hole drilled into the fitting. The dodge garage didn't show that bleed. It showed a restriction in line. Do I not need the restriction or do I need both. Each drawing is slightly different.

[jeff1234]

I also notice there is no check valve and the dodge garage vents to atmosphere. Something is goofy here.

[Reaper1]

It definitely needs a bleed on the wastegate canister side to get rid of pressure that can hold it open.

[ajakeski]

Did you read the page I linked to? Gus explains the whole idea there and how to set it up.

http://www.gusmahon.org/html/boostcontrol.htm

You don't run a restrictor with the manual boost control. The MBC takes the place of the restrictor and becomes an adjustable restriction in the line.

The bleed goes toward the wastgate actuator and allows boost pressure to exit the actuator after the MBC closes. Without the bleed, the wastegate stays open and you have low boost.

[jeff1234]

I examined the picture but didn't read the entire article. My bad. For what its worth I may have asked you the question anyway, just to be sure. I have had many problems over the years with this turbo thing so I am somewhat gun shy and don't want to leave anything to chance. Thanks for your help!

Put it together, it works, YAYYYYYYYYYYYYYYYYYY! I am aware that to much boost is bad for the engine without increasing fuel but when setting it my first adjustments went past 18 psi, torque steer galore. Tells me of the potential for more acceleration. Had 40 + and chip with 20 psi before but always detonated so never saw the potential. running right at 14 psi now.