Im looking to replace the blowoff valve I'm currently running with my procharger setup. I have a blow thru system and the valve is located before the MAF, so it doesn't matter if I vent it to the atmosphere or not.
The problem I'm having with my current blowoff valve, which is a piston and spring style, is that it is not opening at idle, and only seems to vent air when the pressure forces it open, causing it to flutter. I also worry that it is not holding in all the boost. I'm also worrying that it might have a vacuum leak on the diaphragm side, and we all know the pain in the ass vacuum leaks can be.
When I had the original procharger bypass valve, which was a butterfly style, it would open up all the way at idle, and of course, open up properly when I let off the throttle. The only thing that sucked about it was that I knew it leaked boost because the butterfly valve didn't make a good seal against the Venturi. You could see light through it. At least it would open and close properly, and while it didn't make a perfect seal, I knew at least it wasn't bleeding off boost once it reached a certain PSI.
First off, is there any difference between a blowoff/bypass valve designed for a turbo, and one designed for a centri? They should both open up fully under vacuum conditions present during idle and when you let off the throttle. The only thing I can think of is that the piston style valves have springs you can replace or other forms of adjustment. I don't see why there should be any adjustment.. They should be open during vacuum and closed during boost pressure.
I'm thinking of just going back to the stock procharger bypass valve for the sake of simplicity.
Or I was thinking of something like this:
TURBOXS 25MM BOSCH BYPASS VALVE REPLACEMENT RBV-25
http://bit.ly/xuIQjT
I dont feel like welding on a new flange, so I have to stick to a valve that has a hose mount, like the stock procharger valve or the one I posted above.
What does everyone think? Can anyone recommend a better valve for around 100 bucks? What are you all running?
Or is anyone looking to sell a stock procharger valve or something better for a reasonable amount?
Homer
The problem I'm having with my current blowoff valve, which is a piston and spring style, is that it is not opening at idle, and only seems to vent air when the pressure forces it open, causing it to flutter. I also worry that it is not holding in all the boost. I'm also worrying that it might have a vacuum leak on the diaphragm side, and we all know the pain in the ass vacuum leaks can be.
When I had the original procharger bypass valve, which was a butterfly style, it would open up all the way at idle, and of course, open up properly when I let off the throttle. The only thing that sucked about it was that I knew it leaked boost because the butterfly valve didn't make a good seal against the Venturi. You could see light through it. At least it would open and close properly, and while it didn't make a perfect seal, I knew at least it wasn't bleeding off boost once it reached a certain PSI.
First off, is there any difference between a blowoff/bypass valve designed for a turbo, and one designed for a centri? They should both open up fully under vacuum conditions present during idle and when you let off the throttle. The only thing I can think of is that the piston style valves have springs you can replace or other forms of adjustment. I don't see why there should be any adjustment.. They should be open during vacuum and closed during boost pressure.
I'm thinking of just going back to the stock procharger bypass valve for the sake of simplicity.
Or I was thinking of something like this:
TURBOXS 25MM BOSCH BYPASS VALVE REPLACEMENT RBV-25
http://bit.ly/xuIQjT
I dont feel like welding on a new flange, so I have to stick to a valve that has a hose mount, like the stock procharger valve or the one I posted above.
What does everyone think? Can anyone recommend a better valve for around 100 bucks? What are you all running?
Or is anyone looking to sell a stock procharger valve or something better for a reasonable amount?
Homer