Engine/Transmission (1998.5 - 2002) How to limit boost to 45psi with twins

[BigDan]

I can't afford my head work for a few more weeks so since I have the time off work id like to install my twins. It has a wastgate (not that familiar with these) which the guy I bought the twins from said that his truck would hit 60psi with the wastegate and 80psi with out.



The wastegate is made in the usa by Tial Sport #s09033123



Is it adjustable???



Thanks.



I'd also like to do it before the head so Piers can check everythng out and make sure its all good.

 

[robertyoke]

I can't afford my head work for a few more weeks so since I have the time off work id like to install my twins. It has a wastgate (not that familiar with these) which the guy I bought the twins from said that his truck would hit 60psi with the wastegate and 80psi with out.

The wastegate is made in the usa by Tial Sport #s09033123

Is it adjustable???

Thanks.

I'd also like to do it before the head so Piers can check everythng out and make sure its all good.

when you get to 45 psi take foot off the skinny peddle.

it takes fuel to make boost so if you are not as heavy fueled you may not see the same boost as someone with the same chargers.

you should be able to dump exhaust through that wastegate and control your overall boost if the wastegate is large enough.

if your wastegate is not big enough then you will clime in boost after it is fully open.

If your secondary charger is internally gated, you could use both wastegates to control boost.

-robert

 

[robertyoke]

o-yea and the wastegate is adjustable, just limit the boost it sees. Mark kendrick uses a air tool regulator to control his set up, and you can get diffrent springs for them also.

 

[Partyat33]

The problem with twins is its hard to see just 45 pounds. Once it hits in the 30's it goes up way to fast too watch and pull out at 45. Use the external wastegate. I turned mine down to see what it would do and I could only make 23 PSI. The external works well.



Dennis

 

[Mark_Kendrick]

Put it on and test it. You may not have enough fuel to make the 60# the other guy had. If you do, once SHOULDN'T hurt.



Use a 1/4" air tool regulator from home depot to send regulated boost pressure to the bottom port (there are 2, one on top one on the side toward the bottom of the actuator) of the wastegate. by varying the amount of pressure you allow to get to the bottom side of the diaphram you are varaibly weakenning the spring in the wastegate.



If it turns out that you don't make enough boost just use the top hole on the WG. . you will then be assisting the spring instead of defeating it.



FWIW,

Mark



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[Jeff_K]

So what size of spring would you use? There seems to be a bunch of options anywhere from 3psi to 20psi when ordering an external wastegate.

 

[Mark_Kendrick]

So what size of spring would you use? There seems to be a bunch of options anywhere from 3psi to 20psi when ordering an external wastegate.

I'd get the heaviest spring available and use boost to weaken it. when you use boost to blow a valve open you get better exhaust flow at high hp/boost levels. when you use a weak spring and use boost to strengthen it the valve tends not to open fully.



Later,

Mark

 

[Jeff_K]

I appreciate the help! Do you know if there are heavier springs available for Tial or Turbotronics wastegates? (heavier then 20psi?) or is that what you typically use? Thanks again.

 

[Mark_Kendrick]

20psi is usually enough. they go up to ~23



http://www.tialsport.com/gates.html

 

[BigDan]

Oh yeah I have enought fuel... . Mach 5's already installed.

 

[Partyat33]

You really don't need that much fuel. I have by most measures very modest fuel and make about 60 psi.



Dennis