OK.. I'm going to try and sum this up from an outsiders few, sems I have no experience on an AWD dyno..
Originally Posted by
Hatch Man(GsR)
However, there may be a difference between the calibration of Awd and 2wd which would explain the strange numbers... The GTO is a 2wd car, but was run in Awd mode so that the ABS would not freak out when it sensed that the front wheels were not spinning at the same rate as the rear. This would cause the ABS to kick in and possibly slow the rear wheels, which in turn would cause a problem or an inaccurate reading...
Gathering the info from this statement, its seems to me that both rollers on the dyno are connected, unless dissconnected.. So, I'm going to assume that an "AWD" mode, the HP/Trq reading are taken by using some sort of table using the power sent to BOTH rollers.. Correct?
So, your dynoing a 2wd car, in "AWD" mode, which means both rollers are still connected, for the reasoning stated above.. Therefore, I'm guessing that the table using the measure the HP/Trq is still the SAME table use to measure 2wd cars, which means that the front tires are causing the front rollers to "drag", due to no power being at the front wheels.. So, using that same table to calculate AWD HP/Trq, the numbers are much lower on a 2wd car, because the table is equating both rollers, not just the powered rollers..
Correct? thats what I'm gathering from all this..
But doing that is, well, kinda stupid.. 2WD dyno's, the ABS light comes on as well, simply for tha fact the the WSS's are getting mixed readings.. Shut the car off and take it for a drive, no ABS light and it does NO damage to any of the sensor's or ABS system.. as litlespic said, its simply a dummy light..