What is a By-Pass Valve, what do they do, & do I need one?
If you have looked into supercharging long enough or already have a supercharger, I'm sure you have heard or seen the mention of using a By-Pass Valve. In this article we hope to answer your questions regarding what a by-pass valve is, what they do, if you need one, and (if you do need one) what type do you need.
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The By-Pass Valve does just that, it allows air that is being forced down the throat of your motor to be by-passed back into the supercharger or into the atmosphere, depending on the application, and the requirements of the supercharger.
Why, you might ask, is there a need to add more air by bolting on a supercharger and then take it away. The answer to that common question is, when you are force feeding a motor with air, there are times through-out the rpm-range where the motor can not handle more air. One example of this is, if an intake valve is closing on the cylinder heads, there is going to be a moment where it can not flow any air, but will imediately need air there after. Superchargers regulate the rate they flow air by the RPMs of the motor and not in those milliseconds through-out the RPM range that the motor can not handle the amount of air that the supercharger is forcing.
Even though some smaller supercharger systems don't come standard with By-Pass Valves, we recommend the use of a By-Pass Valve anytime you are forcing air into your motor, even at low boost levels. If you are running at pressures in the proximity of 7psi or above, then it is deffinately mandatory to run a By-Pass Valve or your chances of damaging head gaskets, rings, seals, or other important parts of your engine are extremely high, or just a matter of time.
