by pass vs blow off

[97desertCobra]

Hey guys I was wondering what the pros and cons are between the two. I'm currently running a Procharger D1SC on my 97 Cobra. My by pass valve is going out due to a hole in the bladder. So now its time to replace it. But I was wondering what the advantage would be if any in going with a blow off valve. I'm only running 8# of boost.

 

[Cookieman00x]

well, from what I gather, a bypass valve recircluates the air thats already been through the blower and puts it back into the intake of the blower. Some people dont like that because they feel the air being recirculated it too hot.

You would want the Procharger race valve. You can always get the enclosed valve and not hook up the tube to the intake, thus venting it to the atmosphere like a blow off valve or use it as a bypass valve.

I have the Open race version. I havent driven with it yet, but it sound crazy starting it up.

 

[97desertCobra]

^^^I'm speculating that recirculating back into the blower would help with increasing impeller speed and thus alowing the boost to climb faster. But then again centri blowers increase boost based off engine rpm. Some one please clarify.

 

[Cookieman00x]

I dont think it passes enough air to make an HP increase.

 

[97desertCobra]

Ok so I have another by pass question. When I'm in gear and the rpms are high say 4k the by pass valve is going crazy and making that fluttering sound. This is most present when racing from a roll and when making a left hand turn. So I'm wondering if this is normal or if this is due to a hole in the bladder?

 

[01yellercobra]

Recirculating the air doesn't help the blower spin up any faster. That part has to do with the rpm of the motor. The main benefit of going to a BOV is the intake charge is kept cooler. If you keep recirculating compressed air it's just going to get hotter. You won't see any kind of power increase going to a bigger valve, but your part throttle might improve a little bit.

 

[LS1PUSSOUT]

Ok so I have another by pass question. When I'm in gear and the rpms are high say 4k the by pass valve is going crazy and making that fluttering sound. This is most present when racing from a roll and when making a left hand turn. So I'm wondering if this is normal or if this is due to a hole in the bladder?

That is compressor surge. It happens when the bypass valve isnt able to flow enough air to completely vent the system or even when the valve isnt working at all. The hole in the bladder could cause it to not function properly since the valve works off vaccum. The hole causes a vaccum leak which could cause your valve to stop working completely. Be careful with it until you get a new bypass valve. Compressor surge is hard on the supercharger....