QUOTE(tunertoobe @ Oct 5 2006, 07:48 PM)
Weh, this is turning into a physics thread.
Still I will stick to my opinion, RPM is a "small" factor. When they calculate HP, it's torque that they measure. However, RPM is not "that" small, sorry for not clearing that out. I meant that it was like a "supporting cast". Without it, the story won't make sense.
Imagine an engine aking 50 foot-pounds at 4000rpm. That's 38hp. Now how bout making 55 foot-pounds at 3500rpm, 37hp, only 1 hp less but you get the benefit of higher torque and better in-gear accelaration. Honda played around with torque to get the 120hp/litre. It's an old trick learned in motorsports. So in conclusion, high RPM is important but is useless when the torque dies off to easily(which torque tends to do at high RPMs).
Anyways, I'm scared woh, running out of topic.
Ok, our opinion is your, and mine is mine, leave it at that and lets help the threadstarter buying an S2000.
Yes you are running out of topic.. and you use the word torque as thought it is some magic figure that you can pull out of the air. Please give me the formula for HP calculation that does not require multiplying it with torque and RPM.
Honda engines have no torque because you can't produce torque out of a small cc engine and they need the high RPM to produce the power. We are talking about Honda engines here. The VTEC system is nothing more than very wild cams at high rpm in order to maintain sufficient engine efficiency so that torque does not drop. Torque drops when the volumetric efficiency of the air flow drops, as there is not enough air to burn the fuel since the valves are opening and closing so quickly and air can't get into the engine fast enough.
However, running wild cams at low RPM produces another problem, which the VTEC solves by switching to a milder cam to minimise the overlapping of the intake and exhaust valves.
If you can read between the lines above, you'd notice that I've been talking about engine RPM all these while. I can give you 500 foot pounds of torque but it would not be much use if you can't use it above 1500RPM. Maybe you have a different understanding of the relation of torque, RPM and HP than I do.
And Honda didn't play around torque to get the power, they played with RPM. Their torque figures are typical of what a normal engine of similar capacity would produce, they made sure that they can keep the SAME torque figure (notice the keyword SAME) but run it at higher RPM.
How much torque an engine can produce depends on it capacity aka displacement and methods of induction (NA or forced).
This post has been edited by sleepwalker: Oct 5 2006, 09:24 PM