g-valve orifice

[mcsvt]

Well looks like I have located my missing boost. The g-valve was in backwards... Who knows how it got that way but it was...

The orifice on the WG side should be ~.020"(1/50") which I need to do drill because the old nipple broke off. The smallest bit I could find at Home Depot was .03125"(1/32").

My question is, do I make the hole with the bit I have, or leave it without a hole and wait to find another? There are not very many bit resources around me.

[MiniMopar]

You are not going to find a bit that small. You can use a 0.023" MIG welding tip, or just get a restrictor from the auto parts store. Motormite sells one that works under the 'Vacutite" name.

[mcsvt]

Ok so the mig tip or ristrictor would just go in the vacuum line on the side of the WG? I thought the hole in the WG side of the g-valve was to atmosphere?

Just trying to learn, thanks for the help Russ :thumb:

[MiniMopar]

No prob. You basically put a T in between the grainger and the wastegate. Then connect the restrictor to the T. The idea is that the restrictor needs to bleed enough to allow the wastegate to depressurize when the boost drops, but not so much that the grainger can't inflate the can when it needs to. The grainger acts like a check valve, so it can't bleed off the pressure itself.

From the horse's mouth:

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

[mcsvt]

I was reading that whole page early today :) I understand much better now thanks. I put a pin hole to get me around tomorrow, I will see how it works out. The autoparts stores around here are few and far between. Go figure it's one of the most populated areas in the US, o well.

Thanks for the great help :nod:

[Clay]

You are not going to find a bit that small.

you can if you look. We have them at work for our machine shop. In fact you can find them much smaller than 0.023.

[BadAssPerformance]

The last batch I made a couple years ago were dead nuts .020" ;) need to find another drill now tho :(

[mcsvt]

I'll see how the pin hole works tomorrow. Maybe I will actually be able to hold some boost now... Got a bit of a drive to find out on and get it set at the right level.

[SwiftTech]

go to a hobby store and find a pin vise and small drill index. use your 1/32'd drill bit to go almost all the way through but not all the way. Then just do the last bit by hand.

[contraption22]

I use an .020" nitrous jet.

[MiniMopar]

It's really not that critical on the Garrett. I actually used a bleeder valve so that I could tune it to control the wonky Mitsu on myold Shadow.

[mcsvt]

Well my pin hole works, I have steady boost. Just need to turn it down a little. I am hitting about 22psi. The car can handle it, just not what I want right now.

Thanks for all the help guys :thumb:

[Wink]

Glad to hear it's finnaly resolved. Only took you a year to figure it out. LOL

[mcsvt]

Well not completely resolved. Wonder if my pin hole is to big... No mater how I adjust it now, I am still getting full boost like if I had the WG line disconnected. With roommates in tow, I did not have a chance to mess with it, but something is still up. Time to install the ebc, I should put it to some use.

[mcsvt]

As a reply to my reply... I am an idiot, my valve wasn't backwards, but it is now. I don't even know what I was thinking (or if I even was).