[CallMeCrazy]

So going by your motor which is 4,900cc or roughly 299 cid (not sure what your redline is??)

(CID × RPM????) ÷3456 = CFM

(299 × say 6000?) ÷ 3456 = 519.10 CFM

The engine will flow 519.10 CFM of air assuming a 100% volumetric efficiency and assuming a common redline of 6K. Most street engines will have an 80-90% VE.

519.10 × 0.85 = 441.23 CFM

Your 299 cid would flow 441.23 CFM with an 85% VE. A good rule of thumb is that for every 10 hp a gasoline engine makes, it needs roughly a lb of air/min delivered to the intake manifold, so, you'd multiply 441.23 CFM by .07 giving you 30.89 lbs/min and putting your motor at roughly 300 hp naturally aspirated, am I right?

Add in pressure ratio, you said 6-8 psi?

(6 + 14.7) ÷ 14.7 = 1.41:1 pressure ratio. Looking back at the RHC6 chart, you'd be operating on the low end, BUT, I still haven't figured out the density ratio. If you give me your redline and your plans for the motor (how much are you looking to get out of it and at what boost level?) I can figure out where the turbo operates most efficiently.

I still need to come up with a compressor map, but bear with me, I have a lot going on right now.