Let's say you have a n/a engine with X amount of cfm (or lbs/min) at max rpm, and considering that most street n/a engine don't have a 100% ve they're usually at 80-90% ve (+/-) and varies. So knowing this do you choose the comp map that will flow enough air for the engine CFM or the engine VE? The idea is to choose a comp map where the CFM or VE falls right where the comp is at its most efficient. Past couple of weeks I've been doing a lot of searching on how to read and understand comp maps, and yesterday I came across a site that has turbine maps like the comp maps haven't fried my brain already. Oh well off to do more reading and searching about turbine maps

I'll probably have more questions in the weeks to come, so bare with me. Before I posted this, I read all seven pages of the Supercharged/Turbocharged forum to make sure it hasn't been asked before.

Cheers

 

I am no expert, but from what I have read, you need to multiply your engine cfm at a particular speed (i.e. redline in the case of a supercharger) by the pressure ratio you are trying to achieve. Pressure ratio is defined as (14.7 + boost pressure)/14.7, where 14.7 is the air pressure in psi at sea level. If you are significantly above sea level, use the normal air pressure at your altitude.