Here is another PM repsonse I wrote tonight on the subject. I think I finally got some of these thoughts into words in a way that might make some sense. Hope it helps.
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The key to remember is the twisting force is definitely what moves the car, but you can have a twisting force (or any other force) applied, with no motion. The formula for work is Force times Distance. So for work to be done something has to move. You can push on a building with 100 pounds of force, but you arent doing any work, since the building wont move. You may be sweating, but it doesnt mean you are doing work
The definition of one horsepower is 33000 ftlbs of work done in one minute. So now we have distance and time in addition to our twisting force. So tq is what moves the car, but HP tells us what that tq is doing (distance covered over a period of time, aka, work). In the car sense, what it really tells us is at what point in the rpm range we are making torque, since HP is tq x rpm, divided by 5252.
TQ is hard to make. Takes displacement, airflow, etc. In many cases it is easier to increase HP by increasing rpm rather than TQ. This is the way the hondas work. Little tq, but plenty of HP. This is why they can run the same track times as big V8s that make much more tq, but at lower rpm (lower HP). And this is why HP is directly tied to track times, and not tq. My turbo diesel truck makes 600 ft lbs, but at such low rpm its only ~250 HP. A 7200 pound truck with 600 ft lbs (TONS of torque) is still no faster than a car that only makes 250 HP with only 200 ftlbs (but higher rpm). The reason is more TQ but lwo rpm can turn taller gears, and less TQ but more rpm can turn lower gears longer (before redlining), so it all equals out. In fact, in both caes with different gear ratios and different TQ output, WHP will be the same
To make a car faster, sure you can make more TQ. OR, you can make the same (or a little less) TQ, but go to higher RPM and "take advantage of gearing"... The end result is the same, and you see it at the track all the time. Low TQ high reving imports running right with big TQ low reving V8s. ET and MPH depend on HP, not torque, even though TQ is the force moving the car.
Hope this helps!
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And to add a little more confusion to this, lets look one more time at the definition of HP. Just thought of another way to explain it. 33000 ftlbs per minute means that in one minute 33000 pounds moved a foot, or 1 pound moved 33000 feet, or anything in between (33 pounds moved 1000 feet, etc). Has to multpily out to 33000. So lets look at that again. 33000 ft pounds per minute. We have weight there (weight of the car), distance there (1/4 mile), and time there (your ET). So the formula for HP has everything we need to express out ET and MPH (distance over time, both included in the definition for HP above). TQ only has force and distance, nothing about time. So there is no pissible mathematical way to talk about track performance based on TQ alone. This is really the best explanation of it, though it may take a "math type" person to get it.
Hope it helps.