Just an idea for a low boost application..say about 6 PSI.

Since a supercharger is based off the Cranks RPM. The faster it spins the more boost it builds, which makes us choose a pulley based on the amount of boost we want. Using a smaller pulley than intended would build too much boost than we would like at redline. SO..could we use a 12 psi pulley which would build 6 PSI a lot more earlier and cap off the boost with something similar to a wastegate before it hits the intake manifold? Wouldn't this decrease the time it takes to reach peak boost and increase low-mid range power?

Just an example..random numbers here..

6 PSI pulley makes 6 PSI at 9k RPM..whereas a 12 PSI pulley makes 6 PSI at 6k RPM. Then have something similar to a wastegate to bypass the excess boost, letting you reach peak boost and holding it at 6k to redline.

again..just random numbers as an example..

 

in theory yes it makes sense, but thats not the purpose of a supercharger imo...
However, i feel sure it has been done before, it makes sense. But i think you'd have alot of issues getting it to work properly, and probably sound a little too much like a turbo for a SC...

 

I've been researching this, and a wastegate with an electronic controller is more common than you think; a lot of stangs/vettes have this setup.

The usage of parts is different, but the end result is basically a way to let the boost plateau instead of continue to build.

 

Been done works grate search for it there running 22psi and capping it down to 12ect.

 

Sounds like a turbo..but no excess heat? better throttle response? Best of both worlds it seems like..

 

So this works pretty good then?...like on a comptech kit?

928 motorsports has their boost limiter valve.

http://www.928m.com/parts/boostlimitervalve.php

 

Ya this is interesting, since I'm going for low boost.. I'm considering a 11-12 PSI pulley and capping off at 6 to get more power earlier in the powerband. And for the future instead of switching pulleys..all you have to do is change the cap to increase boost? or better yet have a boost controller with multiple tunes? The only downfall I see is your spinning the blower for 12 psi and only using 6..wasting power from the motor to compress 12 psi just to bypass it. But if you do get power earlier in the powerband..its well worth it!

 

Any downfalls with making full boost earlier?

 

why choose a pulley in the middle. Put on the smallest one within the blowers limit and then cap it off. Make 6psi at 6K RPMS. Only one person on here has the BLV installed and he hasn't gotten it adjusted to where he wants it. But 928 will preset it for you.

 

Any cons for creating full boost early all the way to redline?