Stock Wastegate Question

[84GNGary]

What is the other line on the wastegate for ? It is the one that goes to the vacuum block. Also has anybody sucessfully used an RJC type boost control valve with a stock wastegate to run higher boost ?

 

[Jerryl]

What is the other line on the wastegate for ? It is the one that goes to the vacuum block. Also has anybody sucessfully used an RJC type boost control valve with a stock wastegate to run higher boost ?

Gary,
Try this drawing.
(Iit is located in the sticky)

You should be able to remove the vaccum line if you choose to do so.
The RJC boost controller will work fine. No different than an 87.

 

[84GNGary]

I am actually trying to figure out it's purpose and why there are 2 ports

 

[Jerryl]

I am actually trying to figure out it's purpose and why there are 2 ports

Try this link ......... explains "some" of your q's
http://www.turbobuick.com/forums/ho...-tech/19068-stock-wastegate-act-question.html

 

[84GNGary]

Thanks Jerryl.

 

[84GNGary]

Try this link ......... explains "some" of your q's
http://www.turbobuick.com/forums/ho...-tech/19068-stock-wastegate-act-question.html

Thinking about what was in the old post by disconnecting that other line would increase the boost and here is why.

Say if the wastegate was 100% open at full boost of 12 psi, now is the pressure side of the wastegate really seeing that 12 psi with the restrictor in the Y fitting, probaly not. Now by pulling a slight vacuum on the other side of the wastegate diaphram it will take less boost positive pressure to fully open the wastegate. Lets say the wastegate actuator has a fully open stroke at 12 psi. So if the second port was open to the atmosphere it would take 12 psi on the pressure port to fully stroke the wastegate to the open postion. Now if we applied a vacuum of say 8 inches (that is the equilvent of 4 psi) now you would only have to apply 8 psi on the pressure port to fully stroke the actuator to the full open position. So when TurboRegal84 removed that line he no longer had a negitive pressure trying to pull the wastegate open so the only way to get it fully open would be by applying more boost pressure. For some reason that we will never know Buick decide that pushing and pulling the wastegate open at the same time was better
At least I found what I was looking for and have some ideas on how to raise the boost without an adjustable wastegate rod :smile: .

 

[BRAD_PADGETT]

I hate to be the messinger so kill me tomorrow. In my experience I have run both the single vacuum as well as the stock dual vacuum line waste gate actuators. It makes no difference at all in performance. Once you open up your engine the difference nothing. I went back to the stock setup of two hoses to the waste gate. The purpose of two hoses to the waste gate actuator is to relieve pressure while climbing a hill. Good luck Brad

 

[84GNGary]

Brad, have you ever used a RJC type boost controller on a stock wastegate, and if so did it work ? I was told by RJC that the stock wastegate is too weak and it won't work right with the valve.

 

[BRAD_PADGETT]

Gary- I have never used an RJC boost controller and I actually do not know what it does. The waste gate is incorporated with the turbo elbow and it was rebuilt by Limit Engineering. Limit also rebuilt my stock waste gate actuator. I have no problems making boost with the TA33C. I honestly see no need for a boost controller for a stock 84/85 turbo nor a TA33C. At our level opening up the flow in the engine is more important after Alky. One opinion out of a few. Brad

 

[Jerryl]

................ I was told by RJC that the stock wastegate is too weak and it won't work right with the valve.

Interesting. Thinking out loud ...........

The RJC bleeder is in essence a pressure relief valve.
The WG actuator will/should never see any pressure to "activate", until the RJC unit releases and "passes the pressure on" to the actuator.
If the stock unit has a weak spring, and maximizes boost at 12 PSI, BUT does not see pressure, does it matter? Unless of course, the exhaust pressure pushes WG open ............
Not doubting RJC at all, just very interesting.

If you have lag with the 33 there are a few things to look at:
1 Exhaust leaks
2 Fuel / Timing
3 Converter
4 "Y" orifice

If you are trying to raise boost, you can install a bleeder valve to "dial it in" and call it a day.

 

[84GNGary]

Interesting. Thinking out loud ...........

The RJC bleeder is in essence a pressure relief valve.
The WG actuator will/should never see any pressure to "activate", until the RJC unit releases and "passes the pressure on" to the actuator.
If the stock unit has a weak spring, and maximizes boost at 12 PSI, BUT does not see pressure, does it matter? Unless of course, the exhaust pressure pushes WG open ............
Not doubting RJC at all, just very interesting.

If you have lag with the 33 there are a few things to look at:
1 Exhaust leaks
2 Fuel / Timing
3 Converter
4 "Y" orifice

If you are trying to raise boost, you can install a bleeder valve to "dial it in" and call it a day.

I agree, it should not matter. I was going to try an RJC valve which should cause a faster spool because the wastegate will not open at all until the pressure setting is reached.