Torque Talk

[notonp]

Torque is the twisting force of the engine each revolution.torque x rpm =hp

[Azzman460]

I think an important thing to remember as well is that RWKW is not a measurement. A chassis dyno cannot measure RWKW as such, its actually a calculation that it makes by measuring the TORQUE of the engine compared to the speed of the REAR WHEELS at a given ENGINE speed (RPM). This is why you may get different results on a dyno run if your using different dyno's, depending on how the dyno is set up and the calibration you may get varying power results.

[pip_brendanAKAfrosty]

I know what torque is and I know what it feels like when driving a car but all your maths n sh*t is confusing me guys.

[Benji_vs]

Simply Torque is the twisting force an engine produces, power is the work resulting from it.

Example: power equals (torque * rpm)/ a constant

The constant is either 9549 (where torque is Nm) and 5252 (where torque is lb/ft)

A car can produce a heap of torque little power I.e diesel engine because it doesnt rev alot and peak torque happens very low and declines when the revs increase.

A really good example is a Mazda RX8 which produces around 177kw but only produces a crappy 216 nm of torque, why? because it revs very high and peak power and torque is produced at very high engine speeds around 5500rpm for max torque and 8500rpm for peak power.

You can either rev an engine faster to make power or keep it reving the same speed and increase the torque, both increases peak power.

A dyno graph measures torque created at the wheels and uses the above formula to calculate power at the wheels in relation to the rpm the engine is running at.

Like someone above said torque is what gets you there and power is what keeps you there

Hope that helped

[ALF05T]

I like torque.. its simple.

ok torque for dummies

so torque = kw x 9550 divided by rpm . roger that captains??

ok so say a rota makes peak power of 400fwkw at 8000 rpm ---- 400x9550/8000 = 477.5nm

xr6t makes peak power of 400fwkw at 5000rpm -----400x9550/5000 = 764nm

stock xr6t makes 240fwkw at 5400rpm------------- 240x9550/5400= 424.444nm

big ole diesel truck has 300fwkw@1500rpm--------------- 300x9550/1500=1910nm

sound about right??

please note, I dont have an effn clue where a stock t makes its peak power.

Mate that is the best explanation of torque so far, straight to the point!

Cheers Alf

[Rhino1980]

HP and KW are simply a measurement of how much work has been done. Torque is king.

[seduced]

Peak rwkw figures are fine for bragging rights, but it is the way your engine produces torque that matters most.

A nice torque curve is what we all should be chasing, not just a massive peaky rwkw figure. Torque is very much the king.

[SuckSqueezeBangBlow]

torque is what matters most, but being able to use torque over a wide RPM band will make it more useful. torque is what you feel pushing you along as technically you can't 'feel' 300rwkw as its a peak value only.

below is a link to an old article but very worth the read, even if you aren't good at maths - get to the car bits:

http://www.vettenet.org/torquehp.html

[Shark]

Strange how alot of dynos read inaccurate torque peaks.

Can anyone explain as to why this happens? ie: 300rwkw xr6t at about 5750rpm which supposedly reads 1100nm of torque.

Does it have anything to do with the way they enter the cars values into the computer?

[Chris and Liza]

Strange how alot of dynos read inaccurate torque peaks.

Can anyone explain as to why this happens? ie: 300rwkw xr6t at about 5750rpm which supposedly reads 1100nm of torque.

Does it have anything to do with the way they enter the cars values into the computer?

I think it may have more to do with what gear the car was in when it was tested. To get the most accurate results the car should be in a 1:1 gear (4th in ours?) and then the total torque divided by the diff ratio to get an idea of what is happening at the flywheel. It's all got to do with gear ratios - every time the torque goes through a set of gears (torque converter included for autos) the torque gets multiplied by that ratio (ie - flywheel x torque converter ratio x gear ratio x diff ratio / wheel circumference). that's where say 300Nm at the engine can become over 1000Nm at the wheels. Put smaller wheels on if you want more torque lol