external waste gate tuning/hookup.

[4.0l sahara]

So I'm looking to see how people have there waste gate hooked up and what springs etc people are running. At the moment I'm running regulated boost to the top port and the bottom is open. I have just started to play with it first time tuning a external gate. At the moment I have a bws467 and stock sticks haven't dropped my injectors in yet. I can hit about 38 ish psi but anything over 20ish psi my boost gauge flutters. I'm thinking I need a stiffer spring? The regulator is turned all the way up or i believe it is it doesn't seem to bottom out just keeps spinning. So anybody want to shed some incite on setting up waste gates ?
you can see the regulator I'm using in this pic.

 

[Groomzybanshee]

If your boost Gauge flutters you need to check were your gauges hooks up.

 

[4.0l sahara]

My gauge is teed into the mapp sensor line.

 

[Groomzybanshee]

Mine was to it leaked so the Gauge fluttered fixed the leak fixed the problem.

 

[4.0l sahara]

Ill have to double check it.

 

[PowerstrokeJunkie]

Manifold pressure to the bottom of the diaphragm, regulated boost teed from the sensor side of the map regulator to the top of the diaphragm, a 10# spring in the canister seems to work great for me

 

[DZL JIM]

Older thread I know, but I'm trying to refresh my memory how to hook up a waste gate.
So you are regulating the MAP with the same psi thats going to the top port of the gate? That means 25 psi or so to the top of the gate is enough?

 

[PowerstrokeJunkie]

For my setup it seems to work perfectly. I just added a wastegate to an irate mount on an obs that originally didn't have a wastegate, and for this setup I put an actual regulator in the line going to the top hose because the turbosmart hypergate had a 25psi spring in it which was much stiffer than what I was running on mine and may need less air pressure holding the valve closed.

 

[OSCS]

For my setup it seems to work perfectly. I just added a wastegate to an irate mount on an obs that originally didn't have a wastegate, and for this setup I put an actual regulator in the line going to the top hose because the turbosmart hypergate had a 25psi spring in it which was much stiffer than what I was running on mine and may need less air pressure holding the valve closed.

Did you order your spring from turbo smart?

 

[PowerstrokeJunkie]

Aint no way in hell I am opening that canister up if it's got a 6" spring in it.. I got it from the guy at Irate??

 

[OSCS]

Aint no way in hell I am opening that canister up if it's got a 6" spring in it.. I got it from the guy at Irate??

I don't rember what mine came with.. Guess I need to make a call

 

[Powerstroked162]

Older thread I know, but I'm trying to refresh my memory how to hook up a waste gate.
So you are regulating the MAP with the same psi thats going to the top port of the gate? That means 25 psi or so to the top of the gate is enough?

http://www.turbobuicks.com/forums/a...9579d1304720771-external-wastgate-wstgate.gif

 

[DZL JIM]

Thanks for the diagram, that's what I figured.

Now, as to how the gate works, please remind me. The lower port helps keep it closed, or help blow it open?
I really don't feel like taking it apart to see.

 

[4.0l sahara]

The top port/spring keep it closed.

 

[PowerstrokeJunkie]

There is a diaphragm inside. If you didn't know

 

[DZL JIM]

Yes, I remember seeing that, just couldn't remember how it was blown open and kept closed.
Thanks.

 

[OSCS]

Is the fitting on the y pipe the same as the "pressure fitting on the turbo"

 

[Powerstroked162]

Yes

 

[Blowby]

Yes, I remember seeing that, just couldn't remember how it was blown open and kept closed.
Thanks.

Jim the top port will allow pressure from manifold boost or drive pressure to hold the valve closed by applying the pressure on top of the diaphragm. The spring pressure will also hold the valve closed while the top pressure is building. The bottom port is used to control the opening of the valve by allowing boost pressure to be applied to the bottom of the diaphragm if needed. Some do not use the bottom port and just keep it open to atmosphere.

Regulate the top port so the pressure + spring will control when the lower pressure over comes this to crack and fully open the gate.

Example:
Top - Spring pressure force on valve = 10psi and boost on top port is "regulated" to 25psi.

Bottom - It will take 35+ psi to be applied to the bottom of the diaphragm (by manifold boost) or the face of the valve (by drive pressure) to crack the gate.


Drive pressure will also force the valve to open by the nature of the design. If the drive pressure is greater than the boost + spring force on top of the diaphragm, then the valve will open early and you will need a higher pressure spring to offset the premature cracking at a lower than desired boost.

Knowing the drive / charge pressures by data logging will help in setting up the gate or gates. Create predefined settings for fuel, nitrous, daily driving or racing. They will all have different needs and by using waste gates you can be in the sweet spot for all these conditions and keep the turbos from over speeding and staying in the correct area of the map to achieve maximum density.

 

[V-Ref]

BB-Great post.