Quote:
Originally Posted by ozwallaby
Please excuse my behind the timeness.... but I see dyno printouts these days (and for some time) show kph (mph) readings in stead of the old fashioned rpms along the bottom. Does anybody know why this has changed... or why they don't show both readings (rpm and speed) along the bottom?  Good work Matt... and as an old engineering boss of mine used to say "in god we trust... all others bring data..."  |
RPM and km/h are interchangable if you know all the gear ratios in-between. I suspect most dyno operators don't so that's the default.
The only vehicles I've seen dyno'd live were on hub-packs. They stuck a clamp lead on a spark plug and run the engine at 3000rpm to calibrate the dyno. Once they know the overall drive ratio it's run and plotted with wkw vs rpm.
The other advantage of hub dynos is no slippage. With a rubber wheel on rollers the actual rolling radius isn't quite your wheel radius.