I was browsing a couple of RAF files, and looking at the longitudinal wheel force. When going full-throttle, the force is slightly negative for non-driven wheels (because of rolling resistance).

The exceptions were the XRG and XRT. On most tracks, their front wheels have a slightly positive longitudinal wheel force. That would mean that some of the engine power is transferred to these wheels...

The forces are very small (10 to 20 N), so their effect is negligible. But this might point to a bug in the calculations.

If you could create a new RAF file and check if this is still the case when driving at a constant speed in a straight line, that would rule out the possibility of any transient effects creating the forces (not that I can think of any).

Here are two RAF files of the XRG at Blackwood. The screenie shows them in LRA, zoomed in at the main straight. In both, the longitudinal wheel force is above zero. In the second file (red line in graph), I lifted the throttle near the end of the straight. You can see that the force is a bit higher when the car is coasting.

It's not a bug in LRA, btw. F1PerfView shows the same values. Neither is it an artifact of processing by the analyser: the values for the wheel forces are read straight from the RAF file.

haha never thought xrg was awd

Have you tried playing with teo/Ackermann to see how this affects the readings? Tyre pressures?

The angular momentum of the tyre will create a forward force when the wheel is being slowed, but that is not the case during acceleration, nor should the forces be larger htan the rolling resistance.

Quote from Bob Smith :

Have you tried playing with teo/Ackermann to see how this affects the readings? Tyre pressures?

I tried it with zero toe, 100% parallel steer, max tyre pressure, camber tuned to zero degrees... Same result.

Quote from NZL_40 :

well anyway here

Here what?