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Old 11-12-2002, 06:24 PM
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Andy Dunn Andy Dunn is offline
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horsepower sells cars and torque wins races - Myth?
We've all heard this saying, but is it really true? Here is a counter arguement for my old pal HP. I am paraphrasing this info from the excellent engine tutorials at GrapeApe Racing.

Torque gets the car in motion, but TQ and HP are always directly mathematically related and so you can't have one without the other. You can always gear HP to make TQ and therefore you can increase the rpm range of an engine to get greater HP, at the price of TQ, yet when all the smoke clears, you end up with greater rear wheel torque from the screamer. Here is the chart example given on grape ape



The top engine is the torque monster and the bottom is the screamer. The screamer has 50 more HP at peak than the tourquer. The torquer has over 70 more TQ than the screamer at peak. This is a race example to make a point since such steep gearing is not practical on the street. Both engines have the same rear wheel speed, but the higher rpm engine makes more rear wheel torque when all is said and done. TQ and HP are always correlated.

Therefore, for racing, build HP, gear for TQ. There is no mathematical way of getting around that the engine with the greatest average HP for the rpm range will also have more average power.


Andy
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