I often see automakers publish an engine's maximum torque at a specific RPM (i.e. 170lbs-ft@ 3750RPM), but how do I determine the overall "torque curve?"
TIA.
TIA.
acewiza is right, a dyno is the only acceptable way to measure torque curve. Unless you can find some copys of OEM dyno sheets or charts and graphs from dyno testing you are out of luck.quote:
but how do I determine the overall "torque curve?"
Google the engine model and dyno, then select the images option in google. If your engne has much interest to the performance types, there are probably several dyno charts on google.quote:
Originally posted by The Critic:
Besides that.
Torque is a force. Horsepower is work.quote:
Originally posted by Brett Miller:
Torque is actually what does the work when getting a car moving. It's simply a measure of resistance.
Yup. Some steam engines and certain electric motors can exert torque at zero rpm. Since nothing moves, no work is accomplished, therefore no horsepower is developed, even though force is being applied. Think about pushing on a wall as hard as you can without moving the wall. You will get tired, but no work is done. Horsepower is moving a given load some distance in a measured amount of time. 550 lbs/ft of work per second = one hp.quote:
Originally posted by XS650:
Torque is a force. Horsepower is work.quote:
Originally posted by Brett Miller:
Torque is actually what does the work when getting a car moving. It's simply a measure of resistance.
An electric motor develops its maximum torque at stall (0 rpm).quote:
Originally posted by Lazy JW:
Yup. Some steam engines and certain electric motors can exert torque at zero rpm.
Some do, some don't.quote:
Originally posted by b_rubenstein:
An electric motor develops its maximum torque at stall (0 rpm).quote:
Originally posted by Lazy JW:
Yup. Some steam engines and certain electric motors can exert torque at zero rpm.
If you also have maximum hp at a specific RPM you can use the relationship HP = (torque * RPM)/5252 to get another point on the curve. Rearrange it to:quote:
Originally posted by The Critic:
I often see automakers publish an engine's maximum torque at a specific RPM (i.e. 170lbs-ft@ 3750RPM), but how do I determine the overall "torque curve?"
TIA.
Yep. Wife's Aerostar 3.0 is 145 hp and 165 pound-feet of torque maximums. My '95 F`150 is also 145 hp, but 265 pound feet of torque. I doubt there is much difference in their stoplight performance, but the higher torque F150 sure feels faster and is a lot more fun to drive.quote:
Originally posted by BrianWC:
There's a formula tied to hp, IIRC. Torque is your friend and a car with a lot of torque down low is great for stoplight smiles. My big family car Saab 9-5 only makes 185 hp but it makes 211 ft lbs of torque just over 2k rpms so it feels MUCH faster.