I probably have to agree with you on:

>>I think power is the cause that torque goes down at high rpm, instead of designer purposely want it that way.

The most typical example is probably a diesel engine, they can't even rev past 5000 rpm.

I don't always talk with abstract formulas. This time, I read a post (by ifidonlike) that makes a sweeping generality statement about peak hp, uses it to categorically write-off a class of engines, and "to teach others high school physics". Now if he makes such general statements, he better be prepared to defend it when I attack his "theory" with specifically designed scenarios. The more general his claims, the more precise my attacks are. I didn't want to prolong these abstract discussions with you because I know you are above them; but since in my attacks I had to post a sweeping generality myself to achieve the effects, it's only fair that I have to defend it from challengers like you. But if you can agree that we don't have material differences in our opinions, then I see no reason why we should go on. You don't need to challenge something that's a challenge itself, especially since now your challenge is only in the interpretation of things.