By no means am I an expert in this catgory, but I'll try to put in my
observations and see if that helps explain what you've noticed. As an
example, I'll use the new Honda S2000. While I don't have the exact
numbers in front of me, the Honda's overall gear ratio in first is
something like 12.84:1. Multiply the peak torque on that sowing machine
and you get around 1250ft/lbs of torque at the wheels in first gear at
peak torque. The key here is the S2000's 9K (?) redline. This means
that the Honda can hold first gear for a long time compared to other
cars. While the engine may not have much flywheel power, the
multiplication of first gear and the numerically-high (low gear) final
drive ratio means gobs of power at the wheel for 9000rpm's worth of
road.
The problem with building a reliable and fairly cheap high revving
engine is that the engine is usually small in terms of displacement, and
frequently has a short stroke. These two factors make a situation where
the peak torque comes high in the rpm band. Because horsepower is a
mathematical function of the product of torque and rpms, these
high-revving motors numerically produce lots of horsepower at the power
peak. This sounds impressive on paper, but its not as drivable (IMHO)
as a low-rpm high-torque motor, because of the delay in getting that
torque built up. The guy who has to do 6000rpm clutch dumps is gonna
eat clutches faster than the guy who can do 2000rpm clutch dumps with
the same torque to the ground.
Course dependent? Yes. A small, more twisty course is more ideally
suited for the small motors, because of the low speeds and ability to
maintain a lower gear through the course. A straighter course means
more speed, which means a higher gear, which lowers the ability of the
small motor to have its torque multiplied through a low gear and placed
to the ground.
> It seems that many of the newer Japanese cars are leaning towards high
> rpm and horsepower at the expense of torque (new Celica, Type R, etc.).
> When torque does finally kick in, it is around 6000 rpm.
>
> I am wondering if, as far as autocrossing is concerned, this is not the
> ideal situation. I have watched the Type R's run some courses in first
> gear (wince). There were moments when the Acura drivers had to go for
> second briefly, but then back to first. Looked like a lot of work, and tricky.
>
> My wife had a 94 Integra GSL (140 hp) when I had a 96 Neon ACR. Once the
> Acura got going it felt great, but the Neon had more "punch"
> (off-throttle response, especially at low revs). Might this have
> something to do with the relative (DS vs GS) Nationals results?
>
> Seems like this condition would lend itself to some cars success in
> autocrossing being very course-dependant.
>
> Just wondering.
>
> Scott Meyers
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