bhp question..
- Thread starter Matt82
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so obvious i had to post up and ask
the torque is the force behind the acceleration felt, so less torque, less acceleration
Power is torque * RPM
200*2000 < 100*6000 simple as that.
Don't forget you are talking about engine torque, not wheel torque. The engine producing more power, but lower torque would require different gearing to the other engine to make use of it. Something the diesel fanboys conveniently forget
Associate
Power = torque x revs
So,
200 x 2000 (400,000) vs 100 x 6000 (600,000)
The latter produces 50% more power.
So,
200 x 2000 (400,000) vs 100 x 6000 (600,000)
The latter produces 50% more power.
Soldato
The petrol one will be faster.
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But by those examples wouldnt the 200x2000 feel faster due to the torque, while the 100x6000 will actually be faster over all.
ie the 6000 rpm will have a higher top speed, but the 2000 rpm will have more pulling power.
ie the 6000 rpm will have a higher top speed, but the 2000 rpm will have more pulling power.
Caporegime
to be honest its not as simple as he's making out.
you need to see the torque curve really to judge. 200 lb/ft at 2000rpm peak could mean that it holds that torque all the way up tp 6000rpm
but the 100 lb/ft car only makes the 100 lb/ft at 6000 rpm and starts at about 50 lb/ft at 1000 rpm and it raises.
essentially whichever torque "curve" on a graph has more area, will accelerate more.
Its about more than just the peak figure, is what we're trying to say.
you need to see the torque curve really to judge. 200 lb/ft at 2000rpm peak could mean that it holds that torque all the way up tp 6000rpm
but the 100 lb/ft car only makes the 100 lb/ft at 6000 rpm and starts at about 50 lb/ft at 1000 rpm and it raises.
essentially whichever torque "curve" on a graph has more area, will accelerate more.
Its about more than just the peak figure, is what we're trying to say.
No, it depends on gearing, and as Mr LOL says the torque curve. Engines that "feel" fast generally have a very non-linear torque curve, so you get the big push as the engine starts to produce more torque. An engine delivering the same amount of torque over a wider RPM range will be faster, but will probably not feel as quick. In other words, rate of change of acceleration is what you feel more than just acceleration, a constant push with no change doesn't feel very quick, even though it is.
It's meant to be a very simple example.
The first one doesn't feel faster because it has more torque. If I am producing 100 lb-ft at 6000 RPM, then if I could use a gear to produce 300 lb-ft on an output shaft at 2000 RPM, it would require the same energy. This is what a car's transmission does. This is why the second one feels and is faster.
The first one doesn't feel faster because it has more torque. If I am producing 100 lb-ft at 6000 RPM, then if I could use a gear to produce 300 lb-ft on an output shaft at 2000 RPM, it would require the same energy. This is what a car's transmission does. This is why the second one feels and is faster.
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Soldato
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Without gearing, at 2000 RPM. However, if you are travelling at 20 MPH at 2000 RPM, increasing to 6000 RPM will take you to 60 MPH. But, if instead you change gear at 20 MPH so that you are at 6000 RPM, the resultant torque changes from 200 lb-ft to 100 lb-ft * (6000/2000) = 300 lb-ft.
and in that lower gear, if you were at 2krpm, that would = 600lbft. non?
Soldato
