2004 sti bov on evo 3

[Learie Warrick]

ok so i just bought an evo 3 and in the process of learning more about cars. so the evo 3 comes stock with a recirculating bov right? well the bov i have on my car now is vta, a tcc work type 3 or something and i get compressor surge with it. its not bad but i want it gone. adjusting the spring to anything lower than hardest causes the engine to cut off at idle.

i dont have money right now to buy a HKS SSQV or greddy, so my dad upgraded his stock bov on his sti so i made a flange and piping to get that to fit my car. but on idle the valve is partially open and would only idle if i cover the recirc end. so my question is, if i was to recirculate it where the stock bov would normally recirculate, would that work?

 

[Gianni]

If u recirculated it back into intake where stock bov runs then it'll run fine. That way the air isn't just leaving the system, it's going back out the MAF. Which means the MAF is reading all the air leaving the system. If the bov is openin and closing at idle, then extra un read air is getting into the system which would cause it to idle bad and sometimes die.

I have a recirc bov, aftermarket ATM and no matter how I adjust it it'll flutter. But it's better when it's soft because it only flutters at low boost. High boat it just whooshes. When I set it hard it flutters all the time. Not sure why the aftermarket one always flutters when the stok one didn't :s

 

[khubner1]

g send me a vid of what you describe as flutter.

 

[Gianni]

I'll take it for a spin later and do a vid there Is probably something I'm over looking. Getting it tuned in a few weeks so I thought let the tuner work it out

It's not loud but does it at 1psi faintly. But once u hit a fuller amount of boost its fine and just dumps it without the flutter

 

[Gianni]

Did a quick google on compressor surge. Aparently if you change your intake pipe it can cause you to hear the surge as all turbos surge (stock intakes are designed to hide the sound)

That doesn't help us coz I'm assuming we both are running stock intake pipe. Another thing that can affect it is upgraded turbos cooler systems ect. Because it affects spool, amount of air ect the boost controller is programmed different and the wastegate can then play a part.

Again we aren't talking about that because all we did is change the bov. The reason to change the bov is because a metal one will withstand a higher amount of boost. And not leak boost at higher levels. Because of this the valve will naturally be heavier so I'd actually expect some kind of surge from the delay and extra force needed to move the valve.

 

[7zark7]

If you still have a MAF then a plumbed-back Evo X BOV is a good cheap option

 

[EVOCPE]

^^^ BINGO

If you cant find an evox bov then get one from an evo 8 mr

They are cheap these days

 

[Learie Warrick]

made the change and my idle vacuume increased. should i be concerned? everything seems to be working fine.

 

[Gianni]

Moreacc is better. Means no leaks