A friend of mine who KNOWS turbo cars sent me this. I had been looking for a BOV for my WRX. If what he says is true, then I think I would rather put that money towards an intake or exhaust mods. Thanks in advance...

My bud wrote...

subarus dont have intake blow of valves, they have bypass valves. Only differenence between a BOV and a bypass valve is the bypass valve reroutes the air into the intake stream before the turbo. They dont make any sound. The problem with replacing them with a BOV is that the MAF sensor wont see the air flow from the bypass valve and throttle response is hurt as a result.

Any comments?

Also, would someone kindly suggest an air intake that will not produce any check engine light problems. Thanks again.

 

yeah i got a free blitz bov,,and after all that i read here i aint puttin it on,, i dont care for the sound,, i care for power,, imma prob sell it

 

aight, now that we covered the BOV's, would someone kindly suggest a high quality air intake? I don't expect it to make more than 5-10 ponies, but it WILL increase my throttle response and give me better gas mileage. I don't know about the WRX's ... but on my 95 civic EX it gave me 4 more mile per gallon.

(boy i'm glad i sold that rice burner hehe)

 

Short Ram Intakes are the best. I think most will back that up. A short ram lets you hear Intake and BOV noises. Make sure there is a bell shape to the intake so the iar is smooth past the MAF sensor. AVO has a high quality intake. GPMoto will have on for less by next month. Here is a pic of the AVO.

Sean


[www.rallitek.com]

 

Here is a pic of the AVO BOV. It is a sequential design. Recircs and vents.

 

A word on BOVs:
most people install them for the trade mark swoosh sound at shifts. your friend was correct in saying that it hurts the performance it basicaly runs rich.... the only real reason to get a new one would be if you were running boost higher than stock. the stock "Diverter Valve" (or bypass valve depending on your school) has plastic internals, a good aftermarket DV will have alminum internals. the difference. a good aftermarket one will not only hold more bost but have a lower tolerance so it will hold boost a little longer before releasing, this means a smidge more power just before the shift.

I've done a lot of research into this, from what I've found Forge motorsports makes a really nice DV for the WRX

As far as intakes go:
the reason you cant hear the stock DV is because the intake has a silencer on it. you can follow some "how-tos" around the forms here that tell you how to remove it or you can get a new intake. HP graphs show that the Cold Air intakes (intakes from the front passengers side wheel well) make the most power followed by the ram airs that intake from the front girll, and then the little stub nubs are basicaly the filter on the inlet.
the reason for this is simple when it comes to the air going in your car the colder it is the better it is. This is why NOS works so well, it's has little to do with what is in nos it has almost everything to do with the fact that is's a gas thats been compressed so much it's almost liquid... so when it's relased it's ice cold.

The top 3 Cold Air Intakes are AEM's CIA, The K&N Typhoon System, and Injens CIA (I forget the name of the injen system)

from HP graphs the AEM CIA kills everything else in the intake department, and the K&N and injen systems wern't far behind.

 

I'm not trying to be a pusher for this part or anything but if you get a new intake you can hear the sound just as well as most BOVs... also the forge DV has a really nice sound to it even with stock intake

http://www.stratmosphere.com/forge_valves.htm

the WRX valve is near the bottom of the page. pictures and sound clip.

AND it's a diverter Valve so it wont hurt your performance but actualy improve it.

 

NICE APS makes fantastic stuff... my brother has one on his A4 I wasn't aware they made one for the WRX... forget forge ")