turbo blow off valve

[LICKETY SPLIT]

Do I need one with my mc express turbo?

 

[Buckeye]

Blow off

You should not. Are you running the stock waste gate?

 

[JDKRXW]

I thought a blow off valve and a waste gate were the same thing. Am I wrong?

 

[lakercr]

Wastegate is on the exhaust side of a turbo system and controls boost pressure by bypassing some of the exhaust gas to the turbine. A Blow Off valve is on the intake side of a turbo system, and helps to vent boost pressure when you come off the throttle (vent to atmosphere = Blow Off Valve, vent back into intake = bypass valve). By using a BOV you don't send a large pressure wave back to the compressor vanes when the throttle plates close. The pressure wave can slow or stall the turbo, and it can be hard on the turbo as well.

I'm testing different springs and settings on my BOV valve right now. I can let you know my findings when testing is complete....

 

[Buckeye]

Actually the wastegate is controlled by the pressure from the intake side. The swingvalve is on the exhaust side and is opened and closed by the wastegate. The wastegate has a diaphragm and a spring. As boost pressure increases, it pushes the diaphragm against the spring and mves the actuator rod which is connected to the swingvalve. This opens the swingvalve and vents some of the exhaust pressure off. The rate of the spring determines how far the valve opens and how much boost pressure is made by the compreesor. The basic wastegate has a set rate. The McXpress unit is 7.5 #'s. When the force against the diaphragm reaches 7.5 the actuator rod stops opening the swingvalve and the boost stays at 7.5#'s.
Here is an excellent article that explains this in detail:

http://www.geocities.com/MotorCity/5335/controller.htm

 

[LICKETY SPLIT]

blow off valve

Hi Buckeye I plan on using the turbonetics variable boost control #10402, i got it from greg,looks more like next to complete my installation. a very good article on boost control,thanks.

 

[Buckeye]

Variable Boost Controller

Make sure you get an accurate boost gauge. I have a Cyberdyne digital coming. It's a liitle pricey, but good insurance considering the investment already. I am not sur which model I have. It is supposed to stop at 10 #'s and it doesn't with the cheap sunpro gauge I have now.

 

[treewhacker]

Buckeye
Where did you find the cyberdyne digital boost gauge? I couldn't find it, ended up getting a manual one. I did get a Cyberdyne temp gauge. I really like it. Super accurate, you can watch temp change in 1 degree increments.

 

[Buckeye]

Cyberdyne Digital Gauge

I have to give credit to Uncle Ray.
Here is the link:

http://www.jegs.com/cgi-bin/ncommerce3/ ... rmenbr=361