1MAX2NV

iTrader: (5)

The bypass valve version is adjustable from 3 in Hg to 6 in Hg while the blow off valve version is adjustable from 16 in Hg and up. I got the bypass valve with intention to route the air back into the intake but figured I could still use it as a BOV if I wanted. Now, with the new revalation of specs. Would the bypass valve work well as a blow off valve on the stillen SC kit? What kind of vacuum reading do people see on their SC maxima after letting up the throttle?

vortechpower

iTrader: (1)

Im not sure of the answer you are looking for. I think you mean coasting in gear, which is usually around 23-24 would be the max. At idle I see 20. Is that is what you are asking. Hope that helps.

Chunger

iTrader: (1)

Tony, I'm not sure where you got those specs but the definitions of both are just where they are vented to the atmosphere of rerouted back to before the turbo/sc...

I would imagine both to be fine seeing you would want the valve to be closed when accellerating (vacuum "less than" 5inHg normally) or under boost.

1MAX2NV

iTrader: (5)

Chunger...I got the specs from the installation sheet included with my bypass valve. You are right that both would be fine if when accelerating the vacuum is less than 5in Hg. Thanks...

mtcookson

iTrader: (2)

i think those numbers are more relavent to when you are cruising around. when you are cruising you want the bov closed. with the recirculation valve it shouldn't matter as much so as long as you are recirculating the air.

what happens is that, with a bov, upon releasing the throttle on a car with maf you are letting out metered air. if you were to cruise around and the bov were to be open, you'd be either letting out metered air or allowing in unmetered air. if you were letting out metered air the car would run quite right, if you were letting in unmetered air the car would run lean. when you are cruising you'll generally see something like 10 inhg or so (that's what mine averages on a VG30ET, not sure if a s/c VQ would do the same or not). at that 10 inhg you want the bov to be closed so that you don't release or let in metered/unmeted air.

with the recirculation valve it doesn't matter as much. since you're recirculating it right back into the intake it doesn't allow metered air to be released to the atmosphere, which will keep the car from running rich, and it doesn't allow unmetered air in, which will keep the car from running lean.

basically, if you have a recirculation valve and it is open at cruising speed vacuum levels you do not want to allow it to blow the air into the atmosphere.

1MAX2NV

iTrader: (5)

I see what you are saying...but on a SC VQ30DE. The BOV or Bypass is before the MAF. The air wouldn't be metered at all. I guess if I want to use it as a BOV, I would have to put a filter on it. This way it won't suck in unfiltered air.

vortechpower

iTrader: (1)

I dont think your bypass valve would ever suck in air. When your on the gas it will close when you hit vaccum or accelerate harder. Im sure it would work like the bypass valve that comes with the stillen kit. I have my blitz set to release some air at low cruising speed . The bypass valve isnt made to take in air, just out. If you dont like it then send it back if posible. I have used a bypass valve from a evo 8 into the atmosphere with no problems.

mtcookson

iTrader: (2)

yeah, i forgot to add that in there. if the bov/recirculation valve is before the maf then none of that applies.

it'll most likely just blow out some air. it shouldn't take any in but if you want to stay on the safe side you can put on a filter just in case.