ok ok yawl know that I don't Know "" nuthin bout machinery """ So
please
help me here...Gracias senor y senorita ..**

"It;s only Rock and Roll but I like it" <hoocheekoo (AT) rock (DOT) com> wrote in
message
news:6c6cc820-ef4e-46d1-9cba-54a190f35345 (AT) k30g2000hse (DOT) googlegroups.com...
One reason might be that the cars already have a higher top speed than the
tracks can handle, so no need to think about altering that rule.

Although I bet some driver's wouldn't mind a non-overdrive close ratio 5 or
6 speed box on the road courses.

"Chad" <cbstun (AT) safemail (DOT) com> wrote in
news:484ab92a$0$13946$afc38c87 (AT) news (DOT) optusnet.com.au:

That's actually not a bad question, and it has two answers.

The general answer is that there's usually no need for it. The
normal reason you'd have an overdrive transmission is to get better
fuel economy by letting the engine run slower. The tradeoff is
you add some complexity to the gear box, some weight, and loose a
little power (you minimize frictional losses in a gearbox when the
ratio is 1:1). Fuel economy isn't a priority for a race car, so
it makes the best sense to have the top gear be 1:1, and change
the final drive ratio (the "rear gear") as needed to match top
speed to the track.

There's a special case, tho, when a track has a very long straight,
such as Pocono. In this case if you select the final drive ratio
to maximize top speed at the end of the straight, the rpm are too
low coming onto the straight and the car won't accellerate. But
if you pick the rear gear for good accelleration off the corner,
then it hits the rev limiter way before the end of the straight.
So ideally, you want two gears, one to come off the corner, and
another, higher one, for the end of the straight. In that case,
you'd want the 1:1 ratio coming off the corner (the gear box is
most highly loaded then, and that's the strongest ratio), and an
overdrive gear for the higher speeds.

NASCAR no longer allows such transmissions. Their addle-brained
reason is to save money, altho it's hard to see how using one
$2000 transmission instead of a different $2000 transmission makes
any difference, especially to a Cup team spending $10 million
for the year.

The guys who've got some road racing background would, you bet.
The rest of them would be cursing it as one more thing to get
wrong :-)

John

In article John McCoy <igopogo (AT) ix (DOT) netcom.com> wrote:


I always chuckled about them wanting to save teams money,
when they ran 2 races a year on road courses.... (special cars)
and 34 ovals....

But back to the trannies.... it's just a matter of changing
a couple of gears in the box. They change them anyway.
It does save a few revs on the motors, but like you say....
How much is it really saving??
Motors aren't a real issue these days.




Dan
****************************************
When people say, 'can I ask you a question?',
you really don't have much of a choice...

On Sat, 7 Jun 2008 07:33:59 -0700 (PDT), "It;s only Rock and Roll but
I like it" <hoocheekoo (AT) rock (DOT) com> wrote:

When do you think a driver would be able to use overdrive and still
have the responsiveness to quickly accelerate to pass or evade an
accident situation?

I believe also car speeds would likely exceed 200 mph I think N! is
trying to stay below.