still got one, the way it works is u hav two guages, one for amps one for rpm, take the fast guys car put it on the dyno and right down his amp readings at the 3rd stage, also his rpm, then you gear the car to match his amps by gearing up or down, when u hit his amps if your rpm reading is lower suposedly u hav a worse motor, i havnt used it for about ten years,,,,,,,,,,,,,back when i ran a hyperdrive stx, remember that car!
I might still have a set.. I used to race against Greg Greene waaay back when he was designing the thing***before it sold to parma*** The instructions are about useless... EVERY TRACK that was used in the logic is GONE.. so the amp draw he tells you to match is worthless>>>Not to mention when it was developed we were running 1700's and stand up brush unrebuildble stockers.. If memory serves correct it was originally built before the slot machine even came out.. I recall running things like redline, B&R, Wimpy motors back then..(solid ARM)
what chuck(MUDD) posted pretty much sums it up..Its good for repeatibility..
If I can find the set I have Ill post back up... ***IF NOT CALL PARMA... Parma can still make copies of the book for you as they still have the book on file...
One of my friends bought 6 Thor Chassis Dynos from Greg. He planned on distributing them when they first came out before Parma bought it from Greg. I believe he still has them in is garage - mint condition.
Other racers use them on the west coast, but they have upgraded the power supply so that modern stock motors can be run.
I never had a power supply problem with stock motors>>>although I suppose if I had velo gearing I might have.. But 19T required a better PS.. I ended up beefing up one of mine with a better shunt and power supply.. it would take anything you threw at it..
Something I made up, and actually attached to my scaling table...I took an old 10L rear pod, flipped it upside down and mounted it off the side of my scale table.
I took a stock motor and soldered a resistor across the +/- sides of the motor on about 3" wires.
I put a pair of old wide capped tires on the axle in this pod, using white out, I painted one of these tires in two opposing spots on the sidewall of the tire.
I put a couple screws in the table as bumper stops to keep the car being tested from moving forward.
Using a digital prop tachometer on the 2 blade setting, in natural lighting I can pick up the axle speed...while throttling the car up using the car's battery pack and radio.
I also check the amp draw of the load motor with a digital inductive amp meter, and change the test pod's gear ratio until I get the amp load desired.
When all is working I can get a good reference number for axle speed under load to compare with other cars, and I then use a voltimeter to read output voltage from the load motor...which also can indicate higher or lower RPM's.