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Old 06-22-2019, 12:34 AM
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No idea on the amount of HP it would consume. But a 1:1 ratio would theoretically make 27 pounds of boost on a 212. So I’m guessing it would most likely be underdriven. If underdriven 2 :1 so the crank spins twice for each rotation of the blower’s pulley, then it should be 6 lbs of boost on a 212. If underdriven so the blower pulley spins twice for every 3 crank revolutions, it should theoretically make 13 lbs of boost.

Otherwise, a 1:1 ratio should make about 6 lbs of boost on a 420cc.

Someone check my math...
212cc per two crank revolutions means a 212 at 100% VE pumps 106cc of air per crank revolution.
If the blower pumps 300cc per revolution then...
300/106 = 2.83
Since atmospheric pressure is 14.7 psi, 2.83 x 14.7 = 41.6 absolute PSI.
Since most people talk about “boost” we want to know how much pressure above standard atmospheric pressure so we subtract back out 14.7.
41.6 - 14.7 = 26.9 pounds of boost.

The standard v belt pulley on the blower is ~3.27”.
So I think a 2” pulley driving the blower would make around 10-11 lbs of boost on a 212.
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