Quote:
Originally Posted by Captain Snooze
All the torque here sorry I mean talk here seems to be about brake dynos. I am suggesting an inertia dyno will show an increase in power if the rotating mass is reduced sufficiently.
Sorry but inertia dynos DO work that way.
"accelerate that mass from a low rpm to a high rpm...."
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You are correct.
Especially in an "old school" inertia dyno.
But in the newer computerized models you are supposed to enter a value for the rotational mass of the car's drivetrain.
If you check a stock car with the entry for the stock rotating assembly, you will get the same HP result as a modified car with the
adjusted mass for the rotating assembly.
To get an accurate HP number from an inertia dyno you need to know the rotational inertia of the dyno drum
and the rotational mass of the car's drivetrain.
If you dont change that number from the default for that particular car you are testing, AND that car has a lower MOI than the machine thinks, you will of course see an apparent HP increase.
Same thing would happen if you removed mass from the dyno drum without telling the machine.
That is why I have said before: "If you can see a HP change on a dyno due to a rotational mass change - you are doing something wrong".