Quote:
Originally Posted by jrpxxii
BullF-16 you have way too many equations for me to think thru but you sound like you know what you are talking about so I am with you that for the mods, the hp predicted sounds right.
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Yea, its kind of a combo of thermodynamics and fluid dynamics with air being the fluid. It was pretty accurate with my LS3.. Back then I figured with 7 psi added with the install of my D1 on the LS3 i would get just under 50% increase in rwhp. I was at 440rwhp with the cam and headers/tune and a 47% increase to the the 1/2 atmosphere from the boost i would be at 646 rwhp. Well on the dyno we hit 637 at 7psi so pretty close.
Then i figured that when upping the boost to 11psi that was 74.8% of an atmosphere, so 440*.74 =765rwhp. On the dyno i was at 715 rwhp. so a little more loss that i think is due parasitic drag caused in part by the motor having to spin the D1 quite a bit faster.
I dont know how accurate my predictions will be on the new setup but if it is about 515 rwhp on the LSX and 12 psi (if i can get that) 515 * .81 = 407 add'l hp thru boost. so about 922 then subtract a hundred for turning the blower near max rpm to get the 12 psi on a free flowing motor. So i predict about 800 or just a bit more on the dyno.....we'll see
Anything more that 750 and i will be pretty happy. Not a racer so dyno numbers are all i have. Got enough competitive hobbies that keep me stressed out.
One other thought i have been having about the big F1x and F2 blowers at 20 or so psi. It takes quite a bit of motor to turn that large chunk of spinning impeller that fast? So increases to the chassis dyno are not quite as big as for a smaller blower? Remember, i dont know what the hell im talking about here....its just me thinking out loud so flame away