diverter valves used as bovs

[ncctek]

quick question, can a diverter valve be used as a bov, such as the bosch, or greddy type s (used formerly as a diverter valve) be used as a bov? i was wondering.

anybody clarify this? thanks,.

quick question, can a diverter valve be used as a bov, such as the bosch, or greddy type s (used formerly as a diverter valve) be used as a bov? i was wondering.

anybody clarify this? thanks,.

Hey there,

Are you talking about an exhaust diverter valve, aka a heat riser valve used for forcing exhaust to change directions for manifold heating and EGR applications? If that's the case, I doubt it would be up to the task of holding anything over a few psi. Such a valve was never meant to seal a passage completely. On top of that, it wasn't designed for high speed - it would be slow to react, which is not well suited for that application.

[ncctek]

thanks for the reply, but no, i mean u know how some bovs are designed to be recirc' back into the charge piping? and some just vent to atmosphere?


i was wondering, can teh ones designed to recirc be used to vent to atmosphere? i think a dsm bov is a good example, most ppl use them as bovs, but they where designed as diverter valves i believe.... are they all like this?m will a bov such as a greddy type s, that was used as a recirc valve, work as a bov? or is there something i gotta change in teh bov..??

its just cuz the thought ran through my head, that if the diverter valve was meant to recirc, than it leaking would be soo bad cuz it just recircs back into charg piping/turbo, but if they where to leak as a bov, u would obviously lookse pressure, its just a dumb question thats probably an easy answer, or obvious, i just wanted to be 100% sure.

[BrettR]

Yes.

[mx3frik]

Diverter valves dont recirculate into the charge piping. They recirculate into the air intake after the MAF but before the turbo. If they leak they are still leaking boost and its not a good thing. But like its been said, they are fine to vent to the atmosphere. Just dont expect a RFL type sound.


thanks for the reply, but no, i mean u know how some bovs are designed to be recirc' back into the charge piping? and some just vent to atmosphere?


i was wondering, can teh ones designed to recirc be used to vent to atmosphere? i think a dsm bov is a good example, most ppl use them as bovs, but they where designed as diverter valves i believe.... are they all like this?m will a bov such as a greddy type s, that was used as a recirc valve, work as a bov? or is there something i gotta change in teh bov..??

its just cuz the thought ran through my head, that if the diverter valve was meant to recirc, than it leaking would be soo bad cuz it just recircs back into charg piping/turbo, but if they where to leak as a bov, u would obviously lookse pressure, its just a dumb question thats probably an easy answer, or obvious, i just wanted to be 100% sure.

Hey Ncctek,

Sorry, I am unfamiliar with that stuff. I thought you meant a heat riser valve. I would imagine you could rig a recirculating type BOV to vent to atmosphere if the path is not internal - some of those kinds of things have the passage cast right into the piece. But again, I'm way out of my league here with turbo stuff.

[whiplash]

Hey,

A diverter valve can be used as a BOV, however depending on your car's method of air metering it could cause some unfavourable changes. Also, a diverter specifically designed as a diverter wont really give you a BOV sound, so may not really be necessary anyway. The Greddy type-S however, is a BOV, but with a recirculation kit offered for cars with AFM methods that deem is necessary.

For example, on my Supra, the AFM is directly attached to the intake filter, thus everything passing through the filter is being measured, and fuel is added according to that measured amount of air. During air-charging, or boosting, all that air has been metered and fuel added to compensate, and when I release the accelerator, two things can happen to the charged air.

First, if my Greddy Type-S is recirculating, all air is recirculated back into the intake pipes after the AFM, therefore all air has already been accounted for, correct fuel has been added, and all is perfect.
Second, if my Greddy is not recirculating, ie. "blowing off," the air that has already been measured and then "blown off" has had fuel added to compensate for that air that is no longer there. Therefore, this is why people with this type of air metering experience "bogging" or potentially even the engine dying after quick acceleration and then releasing the gas pedal, as metered air is blown off, causing the engine to run very rich for a few seconds.

The best method to defeat this is to change air-metering methods to a meter that can be placed along the intake after the turbo, the closer to the throttlebody the better. Therefore, the meter is after the BOV/diverter, so it doesnt measure any air before it reaches the manifold, therefore air can be blown off as it hasn't even reached the meter yet.

Anyway, hope that helps..

Allan

[4G64T]

Ah yes... The ever important question... Suck or blow? Great info!

P.S. I hate Karmen Vortex Meters