Could someone check my figures?

[Alchymist]

Just finishing up a compressor project, here:
http://www.garagejournal.com/forum/showthread.php?t=341725

First off is the formula correct for CFM calcs -

[Tank size (30 gal) X .536 X PSIG]/seconds
Did a couple runs obtaining these numbers:
60 seconds - 50 PSI
90 seconds - 72 PSI
120 seconds - 95 PSI
150 seconds - 117 PSI
165 seconds - 125 PSI.

Poking the numbers in the formula gives 12.8 Cu Ft / min.
Sounds high for a 3HP 2 cyl compressor.

 

[texasfiremedic]

Using the formula that you give that wold be close enough. I came to an average of 12.74328.