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Rolling road - torque measurement?
Dave Ashurst - 21/12/08 at 10:45 AM

On the typical printout, what does rolling road torque curve give?

Do you get different torque curves if you measure it in different gears?

Or is it independent of the vehicle gearing?

Gearing multiplies torque doesn't it?



I think I'm losing it!

tia
Dave


v8kid - 21/12/08 at 10:51 AM

Shows engine torque. The rr computer knows the engine rpm and the roller rpm and can work out the gearing from that and adjusts the figures to suit


Dave Ashurst - 21/12/08 at 11:10 AM

Thanks kid!
D


MikeRJ - 21/12/08 at 11:14 AM

The rolling road measures torque at the wheels, and then uses a coast down run to "measure" transmission loss to calculate engine torque.

The whole process is quite inaccurate though, the numbers are really only suitable for comparision rather than an accurate power/torque reading. Theoretically different gears shouldn't make any difference as this should be taken into account during the coast down run, but in practice it usually does make a significant difference, which just goes to show how inaccurate the coast down run is at measuring transmission loss.