Torque vs. HP Revisted

[AL427SBF]

I need no convincing, if you jump away from "Club Cobra ... world's largest non-biased Cobra site!" you find all sorts of interesting stuff ...


Bill Hancock
Mechanical engineer and the founder and former owner of Arrow Racing Engines for almost 30 years. He has presented numerous papers and seminars on dyno testing and tuning. He and his longtime friend, Harold Bettes, formerly the VP of SuperFlow Corporation, recently co-authored a book entitled, “Dyno Testing and Tuning”.


"Hot Rodders and beginners like to talk about horsepower and are usually enthralled with only one number, the peak horsepower produced. Professional Engine builders will talk about the shape of a torque curve, where it starts and where it noses over."


"You will learn that the top tuners really focus their work on shaping the torque curve. If a torque curve has too many humps and dips, the driver will never be able to effectively pedal the car at the edge of traction and ultimately will settle for a part throttle setting that is controllable but not competitive."


"Driving a car with a lumpy torque curve is like trying to dribble a football."


http://www.aera.org/engine-professional/dyno-numbers/

Those who take exception to the above, please address directly with Bill Hancock lol.

[olddog]

Originally Posted by AL427SBF

"Hot Rodders and beginners like to talk about horsepower and are usually enthralled with only one number, the peak horsepower produced. Professional Engine builders will talk about the shape of a torque curve, where it starts and where it noses over."


"You will learn that the top tuners really focus their work on shaping the torque curve. If a torque curve has too many humps and dips, the driver will never be able to effectively pedal the car at the edge of traction and ultimately will settle for a part throttle setting that is controllable but not competitive."

You won't find me talking about peak horse power, unless I'm comparing farm tractors used to plow large fields.

Once you have settled on a certain engine and rpm range, of course your tuning is focused on shaping the torque curve. That's all there is left to do.

However if you are trying to decide if you should build a big block or a small block on a certain budget, then Hp is the only way to compare. A 289, with its short stroke, is capable of a lot of rpm, where a 428, with its long stroke, is not. Sure you can make a 4" stroke spin fast, if money is no object, but since we are constrained by a budget, it is fair to say that for the same money these two engines will operate in different rpm ranges. Additionally these two engines will produce very different amounts of torque. The 289 less torque and higher rpm. The 428 more torque and less rpm. So to compare these two engines, Hp (the average Hp over its intended range) is the only way to compare how each engine will perform. Obviously the gear ratio would be different for the two engines.

Originally Posted by AL427SBF

"Driving a car with a lumpy torque curve is like trying to dribble a football."

I couldn't agree more.

[COBRA427]

Just curious, @ what rpm were your peak Hp and torque #'s ?