All I know is that I had an AMT NL Mercury HP that was rated at almost 20lbs of thrust and my buddy had a P-80 that was rated at 18lbs of thrust...My engine had to spool up to 151 K to reach max thrust and the P-80 was much lower, about 119 K...With the engines mounted in the EXACT same planes (HotSpots) and weighed the same, my buddy's plane took off much faster and had more vertical...Although both engines were rated about the same I believe that his JetCat put out more volume and mine put out more velocity and that volume beats velocity in this case...The performance difference was amazing...

Kevin