this might be a stupid question, but i have been talking to my buddy whose really into turbo cars and he was saying that there has to be a way of controlling our boost. he was thinking like an electric controller to the PCM but i was thinking something like changing a spring on whatever limits our boost now maybe?? i dont know. ive been a muscle car guy and into all naturally aspirated V8's till i took a u turn and got my Cooper S. please be gentle w/ the supercharger virgin

 

Boost controllers are for turbo cars, not supercharged. The supercharger is directly tied to engine rpm. There is no way to increase boost other than installing an underdrive pulley.

The MINI actually does have a bypass valve that allows boost to leak out during light throttle operation in order to keep heat down and gas mileage up.

 

lol don't worry about worrying to sound stupid! There are no stupid questions, only stupid answers!

Supercharged engines' boost are controlled by the S/C pulley, so it's physical. There's no way to control it with a boost controller devide.

The only way to change the boost is to change the S/C pulley.

Have fun with your MINI and at that Chicago pulley party!

 

Boost Controller:

 

OK im glad my head hasnt been chewed off yet. if i were to say something like that on the site i was on when i had my mustang i would be disowned. That makes complete sense but how about the bypass valve?? does anybody do anything with that?

btw, the chicago pulley party is final??

 

The bypass valve is a valve that stays open when there is no need for boost. It uses a spring to keep it open. When you hit the gas, the vacuum (I believe) overcomes the spring and slams it shut, thus allowing the SC to boost. It's basically acting as a clutch for the SC even though the SC keeps spinning. It allows the engine to get better mileage while cruising.

There has been much discussion about the valve as it can cause a yo-yo at partial throttle in the 3-4k rpm range. This happens because the spring is not very stiff and when driving on the verge of it closing, it tends to open and close several times before it finally closes. This condition is not seen if you just floor it. Do a search for bypass valve or yo-yo and you'll get a few days worth of reading.

 

of course it might be possible to have a digitally controlled BPV to moderate boost levels, but this is not a good idea because for one, you're supercharger is still going to work just as hard, and keeping the BPV open will just leak the boost. So since your SC is going to turn the same speed anyway, you may as well keep the BPV shut and get all the boost you can.

 

ah, makes sense

 

 

If you want to get that booost much sooner you could do the VGS mod. It also keeps the boost around longer. I did it as an experiment cause it was a cheap and simple mod, so I figured worst case I was out $5 and an hour of time. I've loved it. Took it out before I ent to the track about a month ago, took a little while but I felt the lag come back when I wanted to overtake on the highway. Put it back in and I've been happy ever since. All it really does is change where the BPV gets its air from.

 

Just the oppisite .. Vacuum is what opens the valve. pressure or lack of closes it.. the valve is naturally in a closed state when the engine is off.

 

Just in case you would like to see what the bypass valve looks like here are the three builds, way down at the bottom of the page. https://www.northamericanmotoring.co...t=43546&page=7
The tube that runs from the diaphragm enters the body below the butterfly plate where it responds to the state of vacuum in the duct between the throttle body and the supercharger.

 

the boost controller is the LOUD pedal!!