Well the dyno is functioning with the torque meter, load it up with the valve full throttle till the engine almost dies. Then I open it and let off the throttle. Took a year off from the experiment time to get my motor building back up to par. It worked but now I need to hook it up to a laptop somehow. I have saw the Arduino boards and sensors, so im thinking a load cell, magnetic hall sensor for rpm, temp and humidity, and maybe another temp for egt to tune with. What other sensor would be needed for a hydraulic dyno. I also need some software to run it, I know Alvin had some but I just saw he is no longer cruising the site. Has anyone been successful with the Arduino uno, nano, raspberry setups. If so what software are you using the cheaper the better. Free being the best..