Racegate problems

[BuickMike]

I got a Racegate a few months back and had it rebuilt by Turbonetics. I just finally put it on and cannot get my boost controller to work. I can only adjust up or down about 3psi. I have an 11lb spring in it now and can only adjust between 14 and 17psi. It came back with a 7lb spring and then I could only adjust between 9 and 12psi. Another thing is that the area that I can adjust the boost is only about a 1/4 turn on the knob. Any more turns in either direction and nothing happens. I'm basically using a compressor regulator setup. I used to have a Deltagate connected to it and it worked perfectly. I double checked my hose connections and they are on correctly according to the diagram on gnttype.org. I'm using a Mease DP. What could be wrong? Should I double check my lines to make sure they are not plugged up? Could my regulator have gone bad, or maybe the Racegate was rebuilt wrong?

Thanks in advance for any help.

Mike

 

[BuickMike]

Anyone?

 

[snodgrass]

Sounds like a regulator problem. I use a home made grainger valve system. It's simple and works really well. I can't see how a problem with the gate can give those symptoms.
-Jeff

 

[BuickMike]

Thanks for the reply Jeff.

I found most of the problem:

Everything was hooked up right to the wastegate, but the lines were backwards on the regulator. Now my adjustable boost range is 6psi to 18psi. I should be able to get 25psi no problem. Should I tighten down the stop screw on the wastegate more? When I put in the 11lb spring, I adjusted the screw 1/2 turn past where I felt pressure from the diaphram.

 

[BuickMike]

BTW, what is the Grainger valve and how does it work?

 

[snodgrass]

A grainger valve is simply a ball that is held down on a seat by a spring. (kind of like a needle and seat for up on a carburator float). The spring pressure against the ball is adjustable, which in turn lets you adjust boost pressure. This setup makes for ultra quick spooling of the turbo because there is no pressure at all to open the wastegate untill the boost reaches the preset pressure of the grainger valve. Other "tuner style" systems put pressure on the wastegate diaphram prematurely, and start to open the valve before the set boost pressure, which slows down spool. I get 18 lbs boost in less than one second from idle when I stomp the gas. It feels very close to a good running normally aspirated V8.
-Jeff