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niterydr
08-08-2008, 12:45 PM
Do all dynos read torque the same or are there differences there too?

HUGE difference, please use the search key.

Inertia dyno's (see dynojets) read acceleration and back calculate horespower based on rotational distance, weight of the rollers, and time of the acceleration.

Load baesd dyno's (see dyno dynamics) measure tractive effort applied against a sheer-beam load style sensor as well as engine rpm to establish torque, then back calculate horsepower from there.

A dynojet horsepower formula was originally defined off a motorcycle that had scewed horsepower numbers and was admitted by the designer of dynojets to be screwed high 15% to match the oem manufactures hp estimates.

In the end, I use dyno's for tuning and I race cars. It is important to return to the same facility if possible so you can see gains and changes. I can easily spot when a dyno dynamics graph is "monkeyed with" as the car will make an absurd amount of power "down low" as it is actually reflected "up" on the graph.

In the end comparing dyno numbers is about as useful as comparing penis sizes. Sure you are bigger on paper, but what does that actually accomplish?

MustGoFaster
08-08-2008, 12:47 PM
A dyno will always read HP and TQ in appropriate amount. HP= (TQ x RPM)/5252. They stick to that. But one will read more than the other cause differences in other places.

DJ's read HP and calculate TQ, DD's read tractive effort (TQ after gear ratio's and mechanical advantages are applied) and calculate into HP/TQ.

Roller differences, strap down differences, math applied to the reading differences, calibration differences. Add them up and things aren't always the same.

polishmafia
08-08-2008, 01:28 PM
THANK YOU.

Ok it finally makes some sense.

bob123131
08-09-2008, 02:05 AM
My question was also answered thanks. Sorry couldn't find the lse graph.