blow off valve

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Oct 30, 2012 | 11:11 AM

1fastrock

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From: Chicago

blow off valve

Hey everyone

Been reading up on super charger set ups now that I have mine up and running and I'm looking to improve on it now.

I was reading that a blow off valve can up the horse power of a supercharged motor and I'm not sure how reliable that information is. Does anyone know if it is true?

Thanks in advance
1fastrock

Oct 30, 2012 | 12:48 PM

killernoodle

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Quote:

Originally Posted by 1fastrock

A blowoff valve doesn't improve horsepower, unless in very specific conditions. Most supercharger setups have bypass valves to relieve pressure when the throttle plate closes, but that does nothing for increasing power.

The only time a blowoff valve helps increase horsepower is when you are driving a turbocharged car with a manual transmission. When the throttle closes between gears, the blowoff valve opens and takes a lot of the load off the turbo, decreasing the rate at which the compressor decelerates. When the throttle opens again, the transient lag between gears is generally shorter.

That doesn't matter in a supercharged setup.

Oct 30, 2012 | 12:51 PM

killernoodle

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And the bypass valve is usually necessary on a supercharger because if you were to take your foot off the throttle at 7000 rpms, that supercharger is still trying it's hardest to compress air in your charge pipe. The load put on the blower is greatest at this point and can shred belts, blow out seals, etc. A bypass (blowoff) valve is more of a stress relief item than a performance item.