Grainger valve question.

[itsbudda]

So yeah. I plan on installing a grainger valve in my lebaron quite soon, and this gives me a question. Make it shorter=more boost. Make it shorter=Less boost. Quite simple. But where exactly on the grainger valve is about 8 psi? Basically, where can i set it to where it would do absolutely nothing? As i don't feel like installing it and having it WAY too high to the point where i'll F something up.

Or should i just start from the very end? I imagine with an 87 t1 i can't boost any lower than 7psi.

[EvilcowRoland]

There's not really a magic position with the g-valve. Spring tension is not always a perfect science when you're dealing with mass produced parts like that. A T1 will generally bottom out at 5psi. It'll be closer to 7 if you have a higher flowing exhaust. But what you can do is adjust the valve out just long enough so that you can't blow through the end with your mouth and move the ball, then give it about 2 turns to shorten it from there. That should put it well within the lower boost range. Then just take it for a spin and adjust, shortening it about a turn on each pull. Once you hit the desired level, lock it down and you're good to go.

[itsbudda]

I'm not sure what way to blow from. I tried both. One end i can't move the ball no matter how long or short the valve is. The other one, the longer it gets the easier it is to move the ball.

[itsbudda]

I pretty much have it at the longest it can be. I figure that's a good starting point. I can just trial and error my way from there i assume.

[EvilcowRoland]

Yeah, that's a good way to do it. If you're looking at the g-valve, it's kinda like this:

---[___]-7

A__C_____B

Where A is the long end and B is the angled end. This is the traditional way most people have theirs set up. The ball sits at point C with the spring pointing towards B. Your boost source (turbo outlet or manifold) is connected to A, pushing against the ball. B is connected to the wastegate can. That way, when the boost overcomes the spring and moves the ball, it will flow to the wastegate can and open it. By shortening the valve, you're compressing the spring which makes it harder to move the ball, hence taking most boost to push it before getting to the wastegate can. Hope that makes sense.

Sounds like you have a good handle on how it works, but there's nothing wrong with a little extra info in case someone comes across this and doesn't know.

[itsbudda]

Yeah. They are pretty straightforward. I never really took the thing apart. After hearing about this mysterious "ball" i did. Figured it out pretty quick :yesnod: Thanks for explaining it though. That'd be a good thing to add to the Turbododge FAQ

[Sittn86]

Did you buy one that was already set up, or just a valve as it comes from the factory? It has to be modified to use as a boost controller.

[itsbudda]

Yeah it was already set up. Looks exactly like the one pictured at Donovans dodge garage.

[GLHNSLHT2]

if you blow hard enough one way your brains might blow out trying to get the ball to move hehehe. Just make sure the boost from the intake is pushing the ball towards the spring and not away from it like you were trying to blow. +1 to what the Evil Cow said.

[roachjuice]

i've got mine on the inside of the car. not too long. its shorter than the stock vacuum line going to the passenger side. first time ever driving the omni i decided to see what the boost was set at. yea it was 20psi lol no intercooler. lucky i didn't hurt anything. but i think that short burst like that then letting off will hurt anything. just start with it all the way out then work your way in to your target boost.

[crusty shadow]

yeah definately start with it all the way out and work your way up to your target boost- i just got mine today, put it on, thought i had it set for min boost. nope. shot past 15 psi on an 88 TI. blew the turbo to Tb hose off, lol
after i reinstalled the hose, i opened it up till it was loose- no pressure on the spring. drove it down the street, 5 psi. stop, turn it about a 1/8, 10 psi, just a smidge more, 12-13 psi. set lock nut done. it doesnt take much to adjust it at low boost levels. GO SLOW!

[itsbudda]

yeah i'll be sure to. I'm unintercooled. I'm kinda wondering what the most i can run unintercooled with a stage 2 mopar computer. I figured 14-15. dunno.

[turbokid]

hmmm dont blow her up
Thats the last thing you need

[itsbudda]

oh absolutely. I'm gonna be watching the air/fuel ratio closely. And i don't want to boost too much higher than 12-13

[ol"blue]

What's your reason for not having an intercooler?