Diffrence between blow off and bypass valve

[quicky06]

siimple question whats the diffrence between a BOV and a BPV? just been wondering for a while​

 

[jaxchrisfla]

by pass valve is more like a waste gate.

blow off valve vents the built up air between the turbo and throttle body so that it will not cause damage when all the air is backed up.


Q: What is the difference between a blow off valve and a bypass valve?
A: A blow off valve will release pressure to the air, while the bypass valve will release
the pressure into the intake system between the turbo and AFM.

 

[quicky06]

so the by pass balve just vents air back in to the turbo inlet?

 

[jaxchrisfla]

i believe inbetween the turbo to throttle body side. the bypass are more often used on superchargers though i believe. people usually run a blow off valve and wastegate setups on turbo.

 

[heloboby7]

The difference is where the device puts the "extra" air.

A BPV is usually used in applications where the AFM is before the turbo or supercharger. When the throttle plate closes, the pressure between the blower and the throttle plate build quickly and can cause stress on the blower components if allowed to escape backwards through the compressor. It would stall a turbo (100k+rpms to near 0rpm) very quickly and cause extreme side loading on bearings in superchargers and turbos. The bypass circulates the pressure to the intake tube after the AFM and before the blower to depressurize the charge.

A BOV will vent the excess pressure to the atmosphere. These are good for MAP sensor vehicles and vehicles with a blow through style AFM that is located after the BOV. When a BOV is used on a vehicle with an AFM before the blower, the engine will experience a rich AFR condition everytime pressure is released. This is because the computer has already added fuel for all the air that came through the AFM, and that air gets released before it gets to the combustion chamber.

 

[firetuner911]

so on our trucks, the MAF sensor should be AFTER the BOV????

 

[heloboby7]

so on our trucks, the MAF sensor should be AFTER the BOV????

If you want to vent it to the atmosphere, yes. Or you could convert to a MAP-ECU...

 

[firetuner911]

well you were saying that if the BOV is after the MAF, when the BOV vents, the engine will run rich for a sec becaue the air that was supposed to go to the engine gets vented, so for that reason, shouldnt the BOV be in front of the MAF so it vents the air before it goes through the sensor....

 

[heloboby7]

well you were saying that if the BOV is after the MAF, when the BOV vents, the engine will run rich for a sec becaue the air that was supposed to go to the engine gets vented, so for that reason, shouldnt the BOV be in front of the MAF so it vents the air before it goes through the sensor....

Exactly correct.

 

[ACEE-TL]

let me ask a question. I've seen this done. Not on an x but on a maxima, he had a BOV. Which until then I never heard about having one of a S/C'ed application only on trubo. So the question is..... For a supercharged application which is better a BPV or a BOV?

 

[gixxerman11]

not bpv its DV

 

[Helimx]

DV??
as in diversion valve??? if so, isn't that the same thing???

 

[heloboby7]

DV=BPV. As for what is better in a centrifugal or S/C before the throttle body setup, it really a matter of preference. BOV's are louder though.

 

[jaxchrisfla]

trd and urd both come with BPV's correct?

 

[heloboby7]

Yes. wordswords

 

[ACEE-TL]

So if I were to do the TRD and decide to do a bov it won't effect anything? I know with most turbo applications, if I'm not mistaken, you have to get the right BOV. I'm not a force induction guru or anything, but I heard that the type of BOV effects the turbo not directly, but have an effect on everything???. Is this correct???

 

[heloboby7]

You wouldn't be able to do a BOV on a TRD charger setup. What we're talking about are pressure relief devices between the blower and the throttle plate.

 

[PascoX]

So if I were to do the TRD and decide to do a bov it won't effect anything? I know with most turbo applications, if I'm not mistaken, you have to get the right BOV. I'm not a force induction guru or anything, but I heard that the type of BOV effects the turbo not directly, but have an effect on everything???. Is this correct???

Just concurring with what was stated earlier, the BOV stops excess boost from backing into your turbocharger, thus extending the life of the turbocharger.
The type of BOV you want to use depends on your application and how much boost you plan on running. If you are running too little boost, there is no point in using a BOV, just depends on your application.

 

[RedXr]

so will this work with the roots (trd) system?

http://totallytwistedcreations.com/html/bypass_valve_0.html

 

[Spyder327]

so will this work with the roots (trd) system?

http://totallytwistedcreations.com/html/bypass_valve_0.html

No, thats for the URD system :top: