Boost Pressure

[showeth]

I have just recently installed my new AutoMeter Ultra-Lite guages (EGT and Boost) in preparation for BOMBING. I love the guages by the way. My engine is still bone stock. Truck is a 97 5-Spd dually. The boost levels have been 21psi max. I wanted to see how high it would go just as an experiment by un-hooking the waste-gate line from the back of the fuel pump. I have heard that this will let the boost climb up to pretty high levels. When I un-hooked the line however, the boost remained at 21psi. Did I just receive bad information regarding the function of this? How exactly does the waste gate work?

 

[CRWilliams]

The wastegate doesn't do anything until boost reaches the level at which the wastegate opens. I don't know what this level is, I think it is around 35 to 40 pounds(I'm probably wrong, just a guess). Unless you are making enough boost to open the wastegate unplugging it will make no difference.

 

[JIM S.]

Sounds like to me that your truck being unbombed only makes 21 PSI cause the wastegate is spose to open when the pressure gets to a certain level and thusly keep it at that pressure... . or the other possibility is that your wastegate is stuck partly open and lets your turbo only make 21 PSI, what are your EGT's? a stuck wastegate would seem to me to make EGT's higher (?) ... . so push your fuel plate forward and see what happens ... Jim



PS on a stock truck I think its spose to open around 24 PSI ( I could be wrong)

 

[showeth]

My EGT's are in line with where they should be I think. Pulling hard up hills the most I've ever seen is about 1100 deg. I don't think that the wastegate is stuck. I un-hooked the arm from the pod that controls the waste gate opening and the waste-gate flap seemed to move very freely. Drove the truck down the road with the arm off and what a difference. No boost would build and all power was gone. Can't have that.