View Full Version : supercharger sizing?


rotarenvy
01-08-2006, 01:22 AM
for something to do I'm looking at supercharger compressor matching.

from the rotrex site the first step in determining what compressor to use is calculating the flow required.

rotrex give a rule of thumb that 0.1 kg/s of air is needed to make 120hp. so for 300hp a motor needs about 0.25 kg/s.

from a scan data collection Hymee has done; at 8000 rpm the air flow meter read about 0.22 kg/s and at 9000 rpm it was 0.25 kg/s. if you substitute these values back into the rule of thumb you get 240hp/0.22 = 109hp using this in the previous 300hp target I need 0.27kg/s

in other words the rotary seems to make less power per .1kg/s air.

I have read another guide an it's rule of thumb is 10lb/min for 100hp. same as 0.09kg/s for 120hp.

so anyone have any experience and who's rule should I use as a starting point?

rkostolni
01-08-2006, 11:24 AM
Rotary god has mentioned before that the rotary engine uses about 30% more air as a piston engine to create the same power.