Quote:
Originally Posted by ZeeTwentyFour
Almost everyone uses pound per horsepower ratio's, or want to know how much horsepower a car makes, but that is only half of the story. What I want to know is how do we factor how much torque an engine makes into the performance of car? I always figured torque was more of a low-end off the line kind of thing, where as horsepower was a top-end kind of power. Am I right or wrong?
-James
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Low end torque = low end power. Actually, anywhere where you have torque you have power since
hp = torque*rpm/5252
horse power is what ultimately determines your acceleration but torque is important in determining
when you will get that acceleration. I've created 2 dyno sheets with numbers that I essentially made up. They both make over 450 hp. One is for a torquey engine the other for a 'peaky' engine that makes a few more hp around 6000+ rpm. These engines roughly approximate what a small european V8 would be like compared to say a old 454 big block (though neither chart is based on much more that what I think is a good torque number at a particular RPM)
Its established that both make nearly the same peak power. However, lets take a look at how they behave at lower RPM's. The torquey one is is producing 200 hp at about 2100 rpm, but the other needs to be up to 3600 to make the same power because its only making 100 hp or so at 2100 rpm. This is the advantage of low end torque: more 'area under the curve'