Pottsy.
of course you can compare them, the 2 engines have different torque outputs, no one up to you had mentioned gearing. Even when gearing is brought into it is still a fact that the diesel has far more torque then the petrol Type R engine. What the effect is at the wheels wasn't being discussed
As you yourself point out power = t.ue x revs and the Type R having a higher rev limit produces more power BUT less torque. FACT.
BTW I am well aware of the rev/torque curve cross over
Cylon
Quote:
Originally Posted by Pottsy
Cylon,
You cannot compare the torque of the two cars, since they use different gearboxes and final drives. Torque is multiplied by gears - and since the gearing in the R is reducing wheel revs roughly twice as much as the 2.2 (the R revving to 8,000 compared to 4,000 of the 2.2) then the torque multiplication is roughly double that of the 2.2. So multiply the 150 ftlb of the R by 2 and it's roughly... 300 - the same as the 2.2.
What is needed is a system of measurement which removes the effect of gearing. Then we could compare torques between cars. What we do then is to multiply the torque by revs, so a low revving car that is penalised by its gearing gives a proportionally lower figure. This evens things out. Conventionally torque x revs is called power, and is measured in bhp, PS, kW and so on. Cool eh?
You can read more here:
http://www.civinfo.com/index.php?page=bhp
PS - The formula to convert power to torque (and back is):
Power = torque x revs / 5252 (bhp, ftlb). So any power curve in bhp and ftlb must have the torque and power curves crossing at 5252 rpm - a good check to see if the figures have been "manipulated" by the publisher. |