Quote:
Originally Posted by Gene F
The rule of thumb is that a THM350 takes 25 HP to operate, and THM400 takes 50 HP to operate. That's what the hot rod guys say.... The powerglide sounds like the best choice.
|
Obviously this "rule of thumb" is all wet! Do not believe it! First, if a Turbo 350 really absorbed 25 HP, only 15 would remain and your stock A would be outrun by a stock T! If a Turbo 400 really absorbed 50 HP, your A would not even move when you dropped it in drive!
Second, there is no possible reason why a Turbo 400 would absorb twice as much power as a 350! They both run the same line pressure, so the power needed to drive the front pump would be the same. Torque converters actually easily interchange with small differences in stall speeds so, again, HP loss would be very similar.
Third, while some HP is 'lost' (more accurately, is converted into heat), don't forget that a torque converter actually multiplies torque so the end result is that little performance is lost.
So it would seem that "the hot rod guys" are doing a little too much 'bench racin'!