Dave, the cfm ingested by the motor is a fixed value determined by displacement and efficiency. Whether you run it on hydrazine or peanut oil makes no difference in the cfm. CFM is what it is based on the parameters I mentioned. The fuel you run, will of course make a difference in how you jet the motor. Ethanol runs most efficiently at around 9:1 air/fuel ratio, methanol at around 6:1 and gasoline at around 12.5:1.