You always start selecting your turbos by choosing the compressor housing that best fit your application. Doing this by using this formula CFM=CID/1,728 x Rpm/2 x VE. (VE is at least 100% so use 1.0 for VE)

CFM required under boost- CFM boosted= CFM unboosted x pressure ratio

Airflow is measured in (lbs/per min) to convert cfm to lb/min, a good rule of thumb for 80%F at sea level is to multiply cfm by 0.07.

Lb/min=cfm boosted x 0.07

Every 1 lb/min of airflow is worth about 10hp so to find the required lb/min for a race-only application, start with the horsepower requirement then divide by 10

Lb/min=hp/10

 

Whats is CID?

And what RPM im guessing Redline?

Its like chinese, I had to read it like 3 times lmao...

 

cubic inch displacement