blow off valve on s/c
10-22-2005, 09:26 PM
#24
2nd Gear Member
Join Date: Dec 2004
Location:
Posts: 328
RE: blow off valve on s/c
It really depends on the sustem if your going ot lsoe power by switching from a BPY to a Bov, but as far as i know, for a vortech system or similar sueprcharger systems youll be fine by switching
But there are many case where switching will casue problems, for example, Audis run a closed loop turbo system in their turbo systems (meaning tehy use a bypass valve, also known as a diverter valve used in audis). The computer in the audi expects the air to be redirected into the system, so if you were to switch to a BOV in that particular system, you may infact lose power, and casue problems in the future, with denotation and such...
But that is only an example of how it can casue problems with certian systems, for all i know a BOV or a BPV might work fine with your system
But there are many case where switching will casue problems, for example, Audis run a closed loop turbo system in their turbo systems (meaning tehy use a bypass valve, also known as a diverter valve used in audis). The computer in the audi expects the air to be redirected into the system, so if you were to switch to a BOV in that particular system, you may infact lose power, and casue problems in the future, with denotation and such...
But that is only an example of how it can casue problems with certian systems, for all i know a BOV or a BPV might work fine with your system
10-23-2005, 09:45 AM
#25
5th Gear Member
Join Date: Jul 2003
Location: United States
Posts: 3,451
RE: blow off valve on s/c
Philly is right on how they work.
You'll have problems with the bov in a draw through setup. It likes to toy with the MAF sensor because when it releases metered air causing the car to run rich for a fraction of a second.
You'll have problems with the bov in a draw through setup. It likes to toy with the MAF sensor because when it releases metered air causing the car to run rich for a fraction of a second.
03-08-2007, 03:38 PM
#26
1st Gear Member
Join Date: Feb 2006
Posts: 74
RE: blow off valve on s/c
I just bought a white 1990 Saleen Hatch that is powerdyne supercharged (9psi), power pipe,42 lbs injectors, GT40 heads,msd ignition with boost retarder, b303 cam, shorty headers, o/r h pipe, and flows.What im trying to find out is what bypass valve/ diverter valve would be the best for my application? I want one that will funtion well with my setup as well as be as loud as possible. I heard that the HKS SSQVsuper seuqchal blow off valve was loud, however i dont know if it will work with my application. Will this work and whats involved with the install? thanks - Jay
03-09-2007, 09:40 AM
#27
5th Gear Member
Join Date: Jul 2003
Location: United States
Posts: 3,451
RE: blow off valve on s/c
Wow... this thread is old.... Might as well give a bit of info on some of these topics...
You don't need to tune it if the maf is after the valve if using a bov or you use a bypass.
You don't need a valve for a roots or twin screw in most cases. They are mounted after the throttle body so the rotors are always in a vacuum when the throttle plate is closed. There is no air to damage anything nor will it be bad for bearings or the belt. If you mount it before the throttle body, a bov or bypass is necessary. Centrifugals aren't great on parts without one, but it's hard to cause damage without one especially in a non intercooled setup with short intake plumbing. The centrifugal setups also let air flow backwards through them without too much restriction at low speeds, A roots on the other hand REQUIRES a valve if located before the tb. They don't allow air to flow backwards and they will demolish parts and possibly your entire engine if you don't shut it off quick enough. It's best to run more than one valve just in case one fails.
You won't gain any power from a bov or bypass valve with a supercharger, they are always spinning relative to engine rpm. You will gain with a turbocharger because when the throttle plate closes it slows the impeller down horribly and is not uncommon for them to spin backwards for a split second. Putting a valve on there will reduce lag and give a higher throttle response when shifting. The valves don't offer a performance gain on anything, but you should get one if possible for the sake of parts durability.
Sounds like you're venting metered air or have a vacuum leak. Every bov out there is universal, you just have to get a flange welded to put it on.
Make sure you put it before the meter in a blow through setup if you use a bov. A bypass will work well in a draw through setup.
Bov vents to atmosphere, bypass vents back into the intake before the supercharger. You don't have to set a spring. It operates on intake pressures both before and after the intake. When the air after the tb is in vacuum it helps pull the valve up to vent air, likewise the pressured air before the tb also pushed upward on it.
Which one will work will depend on how big the volume of air being vented is. I would suggest going with a 1.5-2" opening.
Yes, that valve will work. You have to weld a flange onto part of the intake plumbing, then bolt the valve to the flange, then run a vacuum line from one of the lines on the vacuum tree to the valve. Make sure the valve is installed BEFORE the meter.
ORIGINAL: ScreamingYellow
You can put a BOV on any kind of turbine forced induction(Not sure about screw types, etc). It won't help performance but should help release the unnecesary pressure from the turbine. Also, unless you can somehow tune for the change in airflow to the engine when it releases the pressure you have a good chance of shooting flames out of your exhaust from an extremely rich condition.
You can put a BOV on any kind of turbine forced induction(Not sure about screw types, etc). It won't help performance but should help release the unnecesary pressure from the turbine. Also, unless you can somehow tune for the change in airflow to the engine when it releases the pressure you have a good chance of shooting flames out of your exhaust from an extremely rich condition.
You don't need a valve for a roots or twin screw in most cases. They are mounted after the throttle body so the rotors are always in a vacuum when the throttle plate is closed. There is no air to damage anything nor will it be bad for bearings or the belt. If you mount it before the throttle body, a bov or bypass is necessary. Centrifugals aren't great on parts without one, but it's hard to cause damage without one especially in a non intercooled setup with short intake plumbing. The centrifugal setups also let air flow backwards through them without too much restriction at low speeds, A roots on the other hand REQUIRES a valve if located before the tb. They don't allow air to flow backwards and they will demolish parts and possibly your entire engine if you don't shut it off quick enough. It's best to run more than one valve just in case one fails.
ORIGINAL: 4.6MikeMustang
blow off valves DO increase performance under the right conditions, if you had a bad or worn or just too small of a bov, you would cause surging within the compressor of a turbo or supercharger, im using a bov on my supercharger because i needed it, the stock one the super charger kit came with just was'nt good enough once i upped the boost, but depending on where you maf is (draw through or blow through). If you have a blow through such as most procharger kits you can vent the bov into the atmosphere, but if you are draw through like i am it is necessary to have the bov recirculating, but you can buy an aftermakret blow off that sounds cool to you and put that air recirculating back into the flow..
blow off valves DO increase performance under the right conditions, if you had a bad or worn or just too small of a bov, you would cause surging within the compressor of a turbo or supercharger, im using a bov on my supercharger because i needed it, the stock one the super charger kit came with just was'nt good enough once i upped the boost, but depending on where you maf is (draw through or blow through). If you have a blow through such as most procharger kits you can vent the bov into the atmosphere, but if you are draw through like i am it is necessary to have the bov recirculating, but you can buy an aftermakret blow off that sounds cool to you and put that air recirculating back into the flow..
ORIGINAL: catchds
I FOUND THAT THEY MAKE ALL KINDS OF BOVS THAT ARE UNIVERSAL AND WILL TAKE THE PLACS OF MY BYPASS VALVE AND WONT MAKE MY CAR RUNNING FUNNY AT IDLE. THE ONE I AM GETTING IS MADE BY HKS SSQV SUPER SEUQCHAL BLOW OFF VALVE AND IS ONLY ABOUT 150$
I FOUND THAT THEY MAKE ALL KINDS OF BOVS THAT ARE UNIVERSAL AND WILL TAKE THE PLACS OF MY BYPASS VALVE AND WONT MAKE MY CAR RUNNING FUNNY AT IDLE. THE ONE I AM GETTING IS MADE BY HKS SSQV SUPER SEUQCHAL BLOW OFF VALVE AND IS ONLY ABOUT 150$
ORIGINAL: wwmost
I never knew you can put a blow off valve on a s/c. I am still tryin to save up some money for the vortech kit, What bov do you recomend, i want it to sound like a turbo, or will all bov's work fine? where do you put it?
kevin
I never knew you can put a blow off valve on a s/c. I am still tryin to save up some money for the vortech kit, What bov do you recomend, i want it to sound like a turbo, or will all bov's work fine? where do you put it?
kevin
ORIGINAL: wwmost
whats the difference between a bypass valve and a bov? Soo you just replace the bypass valve with a bov? And do you have a set a spring in the bov for how much pressure your running to open at that pressure or somthing?? Im kinda new on this stuff?
whats the difference between a bypass valve and a bov? Soo you just replace the bypass valve with a bov? And do you have a set a spring in the bov for how much pressure your running to open at that pressure or somthing?? Im kinda new on this stuff?
ORIGINAL: RealLow4.2
I just bought a white 1990 Saleen Hatch that is powerdyne supercharged (9psi), power pipe,42 lbs injectors, GT40 heads,msd ignition with boost retarder, b303 cam, shorty headers, o/r h pipe, and flows.What im trying to find out is what bypass valve/ diverter valve would be the best for my application? I want one that will funtion well with my setup as well as be as loud as possible. I heard that the HKS SSQVsuper seuqchal blow off valve was loud, however i dont know if it will work with my application. Will this work and whats involved with the install? thanks - Jay
I just bought a white 1990 Saleen Hatch that is powerdyne supercharged (9psi), power pipe,42 lbs injectors, GT40 heads,msd ignition with boost retarder, b303 cam, shorty headers, o/r h pipe, and flows.What im trying to find out is what bypass valve/ diverter valve would be the best for my application? I want one that will funtion well with my setup as well as be as loud as possible. I heard that the HKS SSQVsuper seuqchal blow off valve was loud, however i dont know if it will work with my application. Will this work and whats involved with the install? thanks - Jay
Yes, that valve will work. You have to weld a flange onto part of the intake plumbing, then bolt the valve to the flange, then run a vacuum line from one of the lines on the vacuum tree to the valve. Make sure the valve is installed BEFORE the meter.
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