I know very little about super-chargers, how is the boost controlled on them? Obviously pulley ratios dictate the speed which in turn makes boost, but is there a by-pass valve on them like a wastegate etc? Do the roots/ lysholm and centrifulgal have different methods?

 

anyone?

 

My Powerworks kit on my Mk1 Fez has a tiny actuator pal

 

what sort of charger' is it mate? , at a guess the centrifugal type? Where does the waste air go, straight to atomsphere?

 

Eaton based one, i'll dig out all the speel, on sec, doin ten things at once mate

 

http://www.magnusonproducts.com/bypass.htm

 

Like that lol

Powerworks sites dead, im tryin to get offline as i feel a geek so late lol

Big will is yer man for powerworks info

 

Eaton M62 roots positive displacement 'charger

 

There is nowhere near the range of control with superchargers as there is with turbos.

I've found that i can increase or decrease my boost pressure by adjusting the exhaust cam vernier...

However. Without doing it on the dyno it's hard to say if i'm actually reducing the efficiency by increasing the boost. Pulley ratios are the best way of setting the boost... But. You have to be careful not to overspeed the charges!

 

Electronic throttle body before the charger is the best option IMHO

 

actuator is an off boost bypass, nothing to do with boost control.

adjusting cam timing will adjust boost purely by restricting flow, or indeed not. boost means nothing on superchargers, its flow.

the only way you can do it is with pulley size, no matter what type of supercharger you got.

only other thing is a wastegate on the inlet side to bleed off boost, but thats just a waste and pretty pointless TBH.

and im out.

 

Hmm, how would you go about controlling a twin-charged set up then where the turbo blows through the charger? Can't remember how to work out the pressure ratios you get when sticking already comressed air through another compressor, sure it is multiply them together?

 

You can still use a conventional wastegate on the turbo to control the boost, although obviously only down to the level the charger is running if there is no other boost control present.

 

Was thinking that chip, but was worried about the turbo pushing too much boost through the charger and having to run a by-pass, and not being able to control the boost the charger was making...

 

If you were running turbo first then the charger (which you pretty much have to if its a displacement charger), you would put the control pipe to the actuator after the supercharger, so that your turbo wastegate didnt allow the pressure after the charger to get too high/

 

Can you remember how to work the pressure ratios out? I should fucking know this, but can't find the info anywhere....

Ie if the turbo makes 10 psi, then goes through the supercharger that makes 10psi, what would your net boost be? I seem to remeber that you multipy the pressure ratios together? But fucked if I can remember how you determine the pressure ratio of a supercharger etc?