Reading a compressor map?
 

I was wondering how we would do it for a rotary?

I found this form. for figuring the airflow/min.....

Airflow = (2/1000)*0.9*(R/E)*S*(303/360)*146.5
R = Engine RPM
E = Engines normally aspirated horsepower
S = 1 + boost pressure (bar)

However, what does a 91 TII make with out the turbo?

Got that form off of this page.......
http://www.mercurycapri.com/technica...bo/htratm.html

James

I don't have time to go through that formula right now, but it looks like it assumes 1 bar ambient pressure and 90% volumetric efficiency. It also looks like they use their particular engine's displacement.

This web site is better. You can use all of the formulas, but just remove the "x 2" from the first equation because the rotary fires twice as often as a 4-stroke piston engine. BTW, there are some math errors on this site, but the formulas look correct as far as I can tell.
http://www.gnttype.org/techarea/turbo/turboflow.html