hp vs. tq ramblings

OK, here is hp and tq explained (it helped me out):
Torque is how much work an engine can do
Horsepower is how often in a given time the engine can do the work

So high torque can do a lot of work, but low horsepower means it cant do it very often (pull down a house, cant do the speedlimit)
High horsepower will do work alot, low torque means it cant do a huge amount of work (go 250mph, cant haul shit)


But then, I'm thinking, shouldnt you just be able to change the gearing to make the high torque engine go fast (higher gearing, lower numerically), and lower the gearing (higher numerically) on the high HP car to make it haul a lot.
hmmm....


About octane: The higher the octane, the more energy is required to cause it to ignite. This stops knock. But if it takes more energy to burn than low octan, then wouldnt it make less power?? The heat energy required to make the rest of the gas/air to ignite is lost, when it could have been used to make the piston go down with more force.
:confused:

Anyone else got questions/answers??

The problem is that you are considering that hp and tq are two different things when in fact they are related. Torque is what really does the work. Horsepower is just a function of torque. You can calculate hp with the formula

hp = (torque * rpm) / 5252

You will notice on EVERY dyno chart or hp torque graph that hp and tq will cross at 5252 rpms assuming the scales are the same.

Here I found this:

http://www.vettenet.org/torquehp.html

Give it a read it's a pretty good explination of the relationship between the two.

I know that hp is a function of tq. Darn, I see what the article is saying. I have some deja vu, but still, it was excellent and helped me out quite a bit (I read it twice, too:))