Q&A Forum
quick question I have my Clayton setup for inertia only I’ve set it up by using a car that has been on my friends dyno we set my moi so the car makes the same power etc in my friends , but I find if I set the gear ratio and do my pull in 3rd gear the power figure comes out spot on , but if I sett my gear ratio to 4th gear it makes nearly 50hp more any ideas ?
the best way to test a car and get the close flywheel hp readings, is to test using the ratio 1:1 to engine, if you try another gear, it's very likely you get more or less hp. for Wheel hp readings, doesnt matter what gear you use.
The MOI must be wrong.
You will get different wheel readings due to friction/speed in different gears. You need to set the MOI so that you get the same flywheel power in two different gears
Hi I’ve been playing with this today like you say adjust the moi to get the same power in different gears , this is impossible as which ever way I change my moi (up or down ) it just increases or decreases the power reading in. It’s gears
The gearbox is changing the torque and HP is just a function of Torque and RPM.
You need to set it up so MOI is correct in the gear closest to 1:1 Then gear ratio in yourdyno should be close to final drive ratio when you do rpm calibration. Wont be exactly the same since you have a wheel size changing it, but it will be close.
MOI will change with each car, But once you have one dialed in with 1:1 gear ratio its close enough. If you wanted some more accuracy then could have a value for FWD and RWD cars.
At the end of the day your not after a dyno that reads bang on accurate HP, If you did youd get a bench dyno. You want one thats close enough in reading HP but mostly gives a repetable run/readings so you can see what difference changes to the tune make.