Author Topic: blow off valvle (Read 4629 times)

richardwagor · « **on:** August 10, 2004, 12:27:21 pm »

Hi,
I'm just starting to tune my 84 quantum.
I just had a straight pipe put on and am very pleased with performance.
Right now my boost gauge tells me that I am only getting 9.5 pounds
of boost max.
I bought an air valve which I plan to install to up the boost with proper fuel adjustments.
My question is this: Won't I have to use a different blow off valve to get more than 14 lbs boost since the stock one vents at 14 lbs?
Also, should I be getting more than the 9.5 lbs I'm getting now?
Does this mean that the blow off could be venting too soon?
Any help appreciated as I am pretty new to this stuff.
Thx - Rich

Dr. Diesel · « **Reply #1 on:** August 10, 2004, 02:37:36 pm »

Quick and dirty fix: The broomstick mod. A 1" length of broomhandle clamped into the safety valve's outlet hose will effectively eliminate it's action. This will allow you to run whatever psi your boost controller/turbo is capable of.
Alternately, you can replace the valve with an appropriately machined block-off plate.

richardwagor · « **Reply #2 on:** August 10, 2004, 02:57:49 pm »

thanks for the reply - I'll try it.
If I did that w/o doing anything to the boost - what would happen?
Do I need to then worry about oil leakage?
Thx again - Rich

Dr. Diesel · « **Reply #3 on:** August 10, 2004, 03:10:59 pm »

it depends on what your boost control/wastegate system is set to at the moment. Perhaps your turbo is trying to boost to 20, but the safety valve is limiting it, but if you're only getting 9.5, then it sounds unlikely. Try it and see!