Thread: m90 bypass valve question

so i was wondering if its even possible to do a mod to the supercharger and make the bypass valve stuck open so the supercharger is functional at all times. and what the pros and cons would be. one bad thing i know already is decreased mpg...anything else good or bad about doing this? or eevn how to do it?

you wouldnt want that. trust me.

you could JB weld the plunger so the valve is closed, but it would cause all kinds of problems. DO NOT DO THIS.

well i didnt necessarily meaN open. i meant like whichever way made the supercharger active at even low rpms. just curious...what would happen?

Cons:
a bunch more heat
more parasitic loss resulting in the fuel economy loss you mentioned, but also putting more wear on the engine
Possible rougher running engine
More part throttle burst knock

Pros:
?

Originally Posted by Scimmia

More part throttle burst knock

That is the one I was going to mention...beat me to it

not meaning to thread jack but i recently "fixed" my BBV problem by plugging the lower line and leaving the bbv nipple open to the atmosphere. will this give me trouble?

Originally Posted by 2000GTP

not meaning to thread jack but i recently "fixed" my BBV problem by plugging the lower line and leaving the bbv nipple open to the atmosphere. will this give me trouble?

No, that's totally different. You still have a fully functioning, vacuum operated BBV; the computer just can't interfere with it anymore. We're talking about totally disabling it and blocking the valve shut like some of the Fiero guys do

i was just thinking that sine the valve keeps the blower from working at low rpms that if it was disabled then the blower would work at all rpms...

Originally Posted by bhrfpa11

i was just thinking that sine the valve keeps the blower from working at low rpms that if it was disabled then the blower would work at all rpms...

It's not about RPM, it's about vacuum levels. At low vacuum (high throttle position), the BBV is closed, so even at low RPM, the blower is pushing air if you push the gas. All this could do is cause more boost at part throttle, but why not just push the throttle more? There's no gains to be had that I know of, and plenty of potential problems.

very, very true. just curious thanks for the info