atmospheric BOV

[Benefit]

ive read somewhere that in order to run a "Atmospheric" blow off valve you need to have a blow-through MAF setup , meaning the maf mounted on your cold pipe...
is this true?

[Big J]

You don't have to, but it'll actually work correctly if you do.

[Kyle]

Just get a diverter valve. Blow off valves are over rated. It's not worth your time, and the only advantage of a BOV is it's a little louder.

[SampaGuy]

u will run slightly rich if u dont have a blown-thru maf setup. just recirculate it.

[Verik]

or get a safc-ii and use the decel function to correct it so u can use an atmospheric bov w/o the blow through

[Benefit]

Just get a diverter valve. Blow off valves are over rated. It's not worth your time, and the only advantage of a BOV is it's a little louder.

excuse me?


u will run slightly rich if u dont have a blown-thru maf setup. just recirculate it.

eh that's the thing...i had the MAF mounted on my cold pipe before , but it ran too rich...i just put it back on the turbo side but the BOV seems fine...how do i go about recirculating?

[Kyle]

excuse me?

I am just saying why not get a diverter valve?

[SampaGuy]

a diverter valve is just a recirculated blow off valve

[Benefit]

ok , after i have mounted my MAF on the turbo side , the car has ran the same if not BETTER , throttle response has increased...doesnt sputter nothing , the idle is alot smoother ,

Tech Tip: This BOV vents to the atmosphere, if you run on your evo you will need an EMS or the HKS EIDS.

ok...?it runs better so whats the problem

[Big J]

What kind of car? What kind of MAF sensor?

If the car is factory turbo and designed/calibrated for a draw through setup, it needs to stay that way, also the sensor type plays a big role.

My car was an NA to FI conversion with a *hotwire* MAF, the IAT sensor is made in the MAF unit, so the MAF stayed where it was and became blow through. Hot wire is the only sensor type that can deal with vastly variying densities of air, a flap or vane sensor won't like pressurised air, neither will a karman, but a hotwire truly measures MASS irregaurdless of density. My car runs great, but each car is diffrent.

[Benefit]

its a 240sx with a SR20DET , using a SR MAF. stock T25g. BOV , FMIC , 3'' Exhaust , 12psi

[Big J]

It's designed to be draw through, so unless you get creative it'll cause problems. You could try a larger MAF housing with a blow through setup to lean it out. I'm sure you can find a solution if you want to run an atmospheric BOV, I know my SAFC has a decel air function to correct for atmospheric BOV on a draw through setup.

[Benefit]

a larger maf will make it run richer.

[SampaGuy]

It's designed to be draw through, so unless you get creative it'll cause problems.


not really cause problems... just gonna be rich for a split second after the bov releases air.

[Benefit]

as in blow flames , yea it does that , but it did that b4 too


oh

the bov sounds weird now , has a lower deeper tone....


i appreciate everyone for helping too but i need some more info