Torque Talk

[wagnman]

I also often wonder what our power figures would look like if we measured useing the BHP method that English dyno tuners use where they use the breaking effect that the cars drive line has on the rollers after they back off to calculate the drive line losses which then gets added to the power they measured at the wheels to give the suposed flywheel hp.

BHP stands for Brake horse power.

[Epic XR6]

You cant have heaps of KW's (Hp)of power.

Without much Nm's (ftlbs) of torque.

IMO just find a big hill drive a small car up it.

Then go back with a diesel 4wd.

This is the first time I really saw torque in action and fully understood it's importance.

Drag racing these two cars in a straight line the small pertol would flog the pants off the 4wd.

But up the mountain range it had no chance.

[JETURBO]

hey sorry to smash up an old thread I would like to know does a mainline dyno convert wheel torque figure to flywheel value or is everything read at the wheels?

[JETURBO]

anyone rattler?

[ratter]

Everything is read at the wheels, the only accurate way to get flywheel power or Torque is to use an engine dyno rather than a chassis dyno, some maths types could probably get a close figure based on what the dyno has reported and they know every ratio, tyre height, roller diameter, slip etc

[JETURBO]

I had a run on a mailine dyno and it said 1065.2 n.m@108 kph but only 340kw trying to work out why the torque is so high but I know the power is so low any hints?

[ratter]

Torque at the rear wheels will read higher than flywheel due to gearing etc, if your car was run in 3rd compared to a run in 4th, the torque will be higher in 3rd, different size wheels basically give a different tyre to roller ratio so can affect torque also if auto, the torque convertor multiplies torque

[TurboMick]

You cant have heaps of KW's (Hp)of power.

Without much Nm's (ftlbs) of torque.

Power is just a function of torque multiplied by rpm.

If an engine creates the same amount of torque, but more often,

it'll create more horsepower.

So technically you can have heaps of power with comparably less

torque.

Eg. An old 5L V8 might make 150kw@5,200rpm and 450Nm@4,400rpm.

Whereas a 4cyl 1L motorbike enginecould make the same

150kw@14,000rpm and only 110Nm@10,000rpm.

I know it's not a fair comparison but you get the gist of it.

Cheers.

[JETURBO]

run in 4th with 19inch twisties just thought the figure was a bit high as it was the same as a 447rwkw falcon that run after me any thoughts? that was also run in 4th with 19 inch argents

[ratter]

Both auto's?

Forget wheel size, it's tyre diameter which affects the tyre to roller ratio

You may have very high boost at a lower rpm as explained by TurboMick