Mike1982

The blow off valve is right behind the drivers headlight. If you go to places on line to see about getting a new one, they have pictures of them so you will know exactly what you are looking for. I replaced mine about 3 months ago with the Saab one.

NZ951

I am using a nippon denso unit. However, a greddy profec A or B would be a good alternative. If you live in an area where changes in temp is not regular. then a MBC will likely be fine, I dont live in those conditions, its quite amazing how much extra boost you can make in really cold conditions.

giddyup

I checked my blowoff valve by disconnecting and blowing through the bottom and sides. I can blow easily with no resistance at all. I'm guessing this thing has been bad for sometime now. Hopefully replacing that with a new one will solve my loss of boost problem at or near redline. Where did you get the Saab one and the nippon denso unit at and how much were they? Thanks for the awesome help guys!

NZ951

My nippon denso unit is bundled with my stand alone computer, you would need a signal to drive it, hence the greddy unit is probably easiest, many guys are using them here. I have an original bypass valve (not BOV, BOV goes to atm), you can have it for shipping expense. It depends how serious with modding you want to get...

giddyup

I'm a little confused. The part I blew into had a Bosch number of 0 280 142 102. This was located right in front of the Strut on the drivers side. Is this a blow off valve (BOV) or a bypass valve. And am I correct to say that it is bad because I can blow through the 2 big ends and have air come out of the little tiny end on top?

NZ951

Blow off valve vents to atmosphere, a bypass valve feeds back into the intake / J pipe. Our cars vent into the intake from stock. I have a MAP system so I vented to atm as it does not influence performance. Do some searches and you will be amazed at the amount of info and pics. I dont have one handy.

giddyup

So this bypass valve from speed 6 should work fine for me? I attached a pic. Thanks for all your help NZ951!

NZ951

Yes it is a bypass valve, if I have the orientation correct, the port on the bottom will feed into the rubber intake J pipe and the side will come from the throttle body IC pipe. You could however block that off on the intake and let it vent to atmosphere, now is a BOV. I would not do that on a stock car though, it apparently causes a very rich state when shifting.

giddyup

Ok, thanks again. I'm gonna order that bypass valve and get that new fuel line for my wastegate to reliaboost and hopefully I'll be able to hold better boost up to redline.

NZ951

Not unless you have a decent WG and maybe a bigger turbo if you want more than circa 10psi