Mayf et al: It is nothing for a 1200 HP big block to run right up to a
5,500rpm stall and then launch. Of course, the rate of slippage goes down
as the car accelerates and the Torque Converter (TC) approaches hook-up near
the traps. The duration may be 1 or 2 seconds for staging and a 9 second
pull (Super Gas bracket). And that is on a very small (8" or 9") converter.
It is that size in order to get the stall speed. There is absolutely no
problem absorbing 1,200 hp for 10-15 seconds. Your typical dyno pull may be
around the same duration. Certainly less than 30 seconds. While, the drags
use a small diameter converter (with fixed volume) to get slippage, "your"
dyno will accomplishes the same thing by varying the flow (volume) through
the converter. That means you can use a much larger unit and you vary the
water flow (to vary slippage or load) with valves. The other thing to
remember is the TC doesn't care at all about horsepower. It only sees
torque and that is what causes slippage or applies the load. HP is just a
calculation. The only effect HP may have is the generation of heat that can
be mitigated by the flow of cool water through the unit. The maximum torque
from the engine will always be at a lower rpm than the HP you are looking
for. As RPM increase, torque & Load goes down. Agreed, even though the
slippage (or load) may become less as the rpm goes up, the generation of
potentially troubling heat increases. I'm also leaving out cavitation, and
other design induced losses here, to keep this simple. They are only heat
generators and I am suggesting that can be managed by open-loop, continuous
cool water flow.
Torque multiplication is irrelevant. It is only a moment arm pressing on a
load cell. That is exactly what you want to do. And the area of GREATEST
torque multiplication (slip) is at the LOWEST RPM where you have absolutely
no interest and the device will never operate there. -Elon
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