The Supercharger on the c230 SLK has an electric clutch. Is this clutch used to shift the supercharger from low -> hi speed (ie low boost to hi boost)? OR is this clutch used to "turn off" the supercharger (ie NO boost to normal boost) ?

 

That's a good one. I would be very surprised to know that there is a "clutch" on the supercharager that would change the speed somehow to increase or decrease boost. Or that there was a high and low speed. Or to turn it on or off. Without the little blower, the performance would be pretty bad on that four cyl. engine, especially since the compression ratio is low to allow for boost. As far as I know, the supercharger spins all the time by a pulley, which is a fixed diameter. Of course, I could be wrong. I've been wrong so many times it's shocking when I actually hit on something.

 

Well actually, if you really think about it, it's not all that hard to do.
The clutch on this supercharger IS an elector-magnetic clutch just like the one on your AC compressor. Using this clutch system along with a simple "planetary gear set" it is easy to allow for the supercharger to spin at one speed (Low boost) when NO power is supplied to the clutch and another speed ("go baby go") when power is supplied. Sadly that is not the case with this unit, which I know now..

THANKS EVERYONE FOR ALL YOUR HELPFUL INFORMATION

 

Thanks

 

The blower on my '05 C230K has no clutch. It's an Eaton blower and has a fixed pulley that you can see in the very front of the engine. Perhaps they changed at one point. Is that photo with the clutch a pic of a C230K and if so, what year may I ask?
Thanks

 

98 - 03 C230 SLK For sure, possibly other years.

 

OK, thanks. Maybe they changed it later on.

 

I have read that there is a clutch and it's purpose is to disconnect the supercharger at idle to assist with fuel economy. I also understand its a Roots type twin rotor supercharger.