I know this will be a never ending discusion, but I know there are pro's and cons to a external blowoff valve. I have one on my wrx and I love it, it has been dyno'd by the way and no power loss from the external blowoff valve was shown. Alot of people will say NO to a external blow-off valve because they believe it dumps the boost and h.p. out. I believe this is possible if and only if you have a adjustable and crank the hell out of it ofcourse your going to lose power if you are concerned with this I would recomend buying a external bov specificly designed for your wrx they do have them out there. I prefer the external for a few reasons: noise, and I have heard many places that it can POSSIBLY extend the life of your turbo by not keeping so much pressure on the turbine at all times what do you guys think?

 

The pressure is not a problem, that is what a wastegate is for. The wastegate will remove any overboost that you have. I have no idea what any pros for BOV would be.

Stephen

 

what kind of bov blows back into the turbo. The stock bov recycles back into the intake, not into the turbo. I am not completely sure of the inner workings of all the interal turbo parts but I thought that the hig pressure was regulated by the wastegate. I am not sure however why the stock BOV is recirculating so EvoEater may be right, he is probably smarter than me anyways. If you can explain the thought behind the recirculating bov evo that would be great.

Stephen

 

Let me start off by saying this and I quote "im not positive", but I have heard that a stock wastegate such as the one that comes on the wrx can actually cause the turbine in the turbo to spin backwards this was one thing that motivated me to go with a external. I love that noise by the way even when your just cruisin' and the forty five year old man next to you in his new tahoe on 20's stops at the light and says "What the hell is that I want one" its worth it for sure.

 

Wastegate and BOV are different things. The BOV releases built up pressure when the throttle is closed whereas the wastegate releases the pressure when it just gets too high all together.

 

recirculating valves direct the pressure from the turbo back into the intake when you let off the gas and the throttle plate slams shut. when you let off the gas......pressure starts to build and a small piston inside the valve is pushed up releasing the pressure behind it. it then lets the pressure escape into the intake track and this air gets used again. it does this so the pressure does not build and slow down your turbo, it keeps it spooled up better.

atmospheric BOV's do the same thing but they release the pressure via a horn directly into the air (hense...."atmospheric")
in this process you get that amazingly baddazz "WHOOSH" sound that we all love to death!!!!


the two types of valves do the same thing just in a different manner. there are really no huge differences in performance between the two.

hope this helps..........later, riggs