Bov on 05 Sti

[Valsti05]

Hello there .. I own a 05 sti .. I've been running my car w an aftermarket bov (hks sequential) recently a friend of mine suggested me to either return to stick bov or an aftermarket recirculating bov .. What at the pro and cons of having a sequential or why would he suggest to change bov .. He didn't really explain why he was telling me this

 

[Alin]

If the car was not tuned, an intake, bov, and other various mods will either make you run rich or lean. The tune is the most important aspect of the cars health.

Give us some more information on the car. How long have you had it? What other mods are on your car? Was it tuned for the bov? Did the check engine light ever come on or flash?

 

[Valsti05]

If the car was not tuned, an intake, bov, and other various mods will either make you run rich or lean. The tune is the most important aspect of the cars health.Give us some more information on the car. How long have you had it? What other mods are on your car? Was it tuned for the bov? Did the check engine light ever come on or flash?

As of now the car has an injen catted downpipe , hks catback exhaust , hks drop in air filter , Cobb accessport stage 2 map (California)I bought the car in 2004 then in 2006 I bought the bov I mentioned above , installed it but never tunned after installing , car ran fine , no check engine light or any issues... This is the reason of my question ..

 

[Alin]

Ok youre running rich. Im assuming youre on stock intake hence the "drop in filter".

The stage 2 OTS map accounts for a turboback exhaust. By adding a bov youre disregarding the tune. The OTS is rich as it is but youre making an even richer state by having the bov added. Someone else with more knowledge can delve deeper into this.

Fyi, any engine mod (very few exceptions) requires a protune or etune to have the parameters adjusted to compensate the mod, such as your bov.

Get rid of it and revert back to the stock bpv until you get a tune.

If you want noise coming from your valve, go with a forge bpv and you wont need a tune. (Only time youd need a tune for that is when you want more power, youd have to swap out the spring inside it to adjust to a higher boost)

 

[Valsti05]

Ok youre running rich. Im assuming youre on stock intake hence the "drop in filter".

The stage 2 OTS map accounts for a turboback exhaust. By adding a bov youre disregarding the tune. The OTS is rich as it is but youre making an even richer state by having the bov added. Someone else with more knowledge can delve deeper into this.

Fyi, any engine mod (very few exceptions) requires a protune or etune to have the parameters adjusted to compensate the mod, such as your bov.

Get rid of it and revert back to the stock bpv until you get a tune.

If you want noise coming from your valve, go with a forge bpv and you wont need a tune. (Only time youd need a tune for that is when you want more power, youd have to swap out the spring inside it to adjust to a higher boost)

got it ... Thank u so much for the info

 

[Spamby]

[MENTION=4391]Valsti05[/MENTION]

Our cars are designed to use a recirculating BPV because of the position of the BPV vs. MAF. The MAF is at the beginning of the intake track and the BPV is sandwiched in the middle. The MAF measures the air incoming into the system. The factory BPV recirculates the metered air back through the system when the throttle is lifted and the engine pulls vacuum.

The reason for not using a vent to atmosphere valve is that your releasing the metered air, as measured by the MAF, to the atmosphere and not back through the system. The system thinks there is that air there and has adjusted fueling for that. The engine can run momentarily rich, sputter and even in extreme cases idle erratically or even die, especially at sudden throttle lift.

What in essence you create by adding a VTA BOV is vacuum/boost leak.

The factory BPV is quite capable of holding boost and can be audible if you do a silencer delete. Of course a CAI will make it more loud, with a tune, of course.

 

[Valsti05]

@Valsti05

Our cars are designed to use a recirculating BPV because of the position of the BPV vs. MAF. The MAF is at the beginning of the intake track and the BPV is sandwiched in the middle. The MAF measures the air incoming into the system. The factory BPV recirculates the metered air back through the system when the throttle is lifted and the engine pulls vacuum.

The reason for not using a vent to atmosphere valve is that your releasing the metered air, as measured by the MAF, to the atmosphere and not back through the system. The system thinks there is that air there and has adjusted fueling for that. The engine can run momentarily rich, sputter and even in extreme cases idle erratically or even die, especially at sudden throttle lift.

What in essence you create by adding a VTA BOV is vacuum/boost leak.

The factory BPV is quite capable of holding boost and can be audible if you do a silencer delete. Of course a CAI will make it more loud, with a tune, of course.

great thank u for the info guys .. Now I have a better idea of what to do and where to go from here...

 

[HolyCrapItsFast]

http://igotasti.com/vBforum/showthread.php/216-Guide-to-BPV-s-and-BOV-s

There is also this explanation:tup:.