So I built a hydraulic load cell so I can test the efficiency effects of things like gear ratios, controller settings, operating voltage, etc.

I used a jackshaft so I could run the same sprockets on the test rig as on my car while keeping the hydraulic pump speed within its normal operating range.  The pump outputs to a hose with a ball valve and a pressure gauge.  The jackshaft has a speedometer calibrated to the size of the drive wheel of my car. The motor is run at a speed that gives the desired wheel speed and then the ball valve is closed to the point that the amperage draw reproduces the same load that I have seen in race conditions. The pressure, speed, voltage, and amperage draw are noted and then become the baseline for comparison of any subsequent changes. If I can find a change that allows for the same speed and pressure to be achieved at a lesser wattage then I have improved my efficiency.

Should make for some fun testing.