Real World Torque Figures

[donkeypunch]

hey all,

my GTR is running 345AWKW, the torque figures where 950NM of torque which sounds a bit much to me. ive been told that the dyno needs to be adjusted to give real torque figures, to do with the drive ratio??????

its a bit over my head, but anyway can you work out the real amount of torque by the torque figure given?

cheers

[R31Nismoid]

Its not torque, its tractive effort - its different.

[donkeypunch]

ok, ive never even heard of 'tractive effort'

so can torque be read on a dyno?

[Adriano]

You can calculate it

[GTR1993]

yep.

power is torque times by angular velocity. You know your diff ratio, gear box ratio (usually 1:1 in 4th) and tyre diameter. You know what power you made at what speed, then work backwards.

[Adriano]

Or even easier, what tractive effort, its already in Newtons. Just make sure the powerr run is done in 4th, as then you dont need the gearbox ratios.

Edited July 15, 2009 by Adriano

[allthewaytotheskyline]

can anyone tell me why some cars have for example 250rwkw but only 400nm of torque and some with 200rwkw and 400+nm of torque???

why is that and whats the key to more torque.

[GT-RZ]

First up tractive effort is a Force (Mass * Acceleration) not a Torque.

You have 950Nm which is a moment or torque if you like. (Force * Distance)

So who said it was tractive effort?

For the answer earlier. No you can't work out exactly the engine torque from the chassis dyno. Too many variables and losses. you can however estimate it.

If that is infact your Torque @ wheels (or centre of the axle to be correct) Then you simply divide by your diff ratio (4.36?) and gear ratio (1.00 if in fourth) You then have the torque @ the engine but not accounting for drivline losses which varies...

You either read your dyno sheet wrong or you've got 950Nm of torque @ the wheels...