Quote:
Originally Posted by oldsinner111
torque has always puzzled me a little.It used to be with gassers torque numbers were higher than horsepower.Diesels always had extreme torque over hp. Now a days I was looking at some newer rides,and hp is over 200 hp over torque.I was taught torque won races,and horse power was for bragging. Are these manufacturers just fooling people.
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Remember that Torque and HP are mathematically related - every engine generates the same ft-blf's and HP at 5250(?) rpm. Its in the equation.
Also remember that engines can be tuned to make more power at a certain rpm. Put a low-rpm cam, tune the intake and exhaust and you can make more power at high or low rpms....but usually not both.
...And this makes sense when you figure that a dynamometer probably just measures twisting force (torque) - so it probably measures torque and does the math to calculate HP (it must know what engine RPM is ?)
Where it gets sticky is the high and low revving engines.
My old motorcycle had 48ftlb and 94hp - it had a redline of 13k. I'm sure that that HP peak was close to 12k and the torque peak was lower. The higher you rev a gas engine (given that the cam/valves/intake/exhaust components are all ok for it) the more twisting force you get.
Big truck diesels that have huge torque numbers but only rev to 2500 rpm. If they revved to 5250 (...if diesel engines were capable of revving and making power that high...), I bet that the HP number would be the same - but in a Diesel, physics intervenes (IIRC diesel burns slower, flame front etc isn't as efficient above 4k or 5k rpm?... so even the Diesel race cars only rev to 5000-something rpm).
Hopefully I'm not far off.
-John