Without larger/smaller pulleys, the Mercedes supercharger puts out crap. You need to get the compressor to run about 14,000 rpm off the crank. However the pulley on the supercharger is 3.5" and since it is an electric clutch, you cant mill it down. So youi either need to run a 8 or 9" crank pulley, or do a double up pulley set up to get the compressor to rev up the the right rpm.
I did reinstall the stock crank pulley and purchased a new belt and now have the compressor up to about a maximun of 9000 rpm and it now does have more power, just not alot.