Destiny2002

FCGuy

Sorry my fellow NYNY'r. If the redline increased, and made more power up there (actually, all it has to do is keep from falling too rapidly) you would indeed get better acceleration. Why? Instead of having to grab the next gear, which would drop the torque multiplication, you get to stay in that higher gear longer. Or in the exact same mathematical language, you'll be making more hp than if you upshifted.

You can do the experiment by shifting early. If you don't accelerate slower by shifting early then I'll concede you are right

FCGuy

Okay, D2002, I agree you did well pose the question.

On my last post, a clarifier:
Depends what one means by "accelerate faster". If torque doesn't go up, yes you do not get increased accel (higher m/s2) than you had a fraction of a second ago. But you will accel better than if you did not have the extra rpm, and thus had to upshift. Result is a better 0-60, 1/4-mi, etc. Which I take to mean "accelerate faster".

And I agree with micah as do I think most here. Like high revs, like shifting, S2000=good. Otherwise S2000=probably not for you.

FYRHWK1

[QUOTE]Originally posted by FCGuy
[B]Sorry my fellow NYNY'r.

micah

The torque used to turn the drum is totally different than the car's torque! It depends on the size of the drum, etc, etc. The torque is an intermediate step to measuring power, which is what a dynamometer does by definition.

My bathrooom scale has a strain gauge internally that works based on resistance; that doesn't mean that my bathroom scale is measuring my resistance! It's an internal step to the device.

Power is quite easy to measure directly without a specific internal torque measurement step. Ever ridden one of those stationary bikes hooked up to a generator and a light bulb? There's no torque being measured there.

FYRHWK1

[QUOTE]Originally posted by micah
[B]
The torque used to turn the drum is totally different than the car's torque! It depends on the size of the drum, etc, etc.

micah

If you were thinking this, I think I see the source of the confusion. HP is power; or WORK over time, or torque TIMES revs; but not torque over time, at all.

Again, there is no way that a dyno can measure your engine's torque unless you know the intermediate gear ratios. But the dyno can tell how much POWER your engine is putting out, minus friction. The fact that a dyno may measure torque internally is simply a confounding factor in this conversation, which is about flywheel power vs torque.

Anyone who's familiar with dynos can tell you that a dyno can tell you power without knowing anything else, but to get torque from it, you need to give it all kinds of information about tire diameter, gearing, and engine revs. This tells you that power is what's being measured and torque is what's being calculated. That's why the definition of a dynamometer is a device that measures power.

A dyno can't know the turning force of the wheels; it doesn't know how big they are. All it knows is the result on the drum. It could be a 2" diameter wheel turning 40 rpm's or a 20" diameter wheel turning 4 rpms, and the drum would never know the difference; all it knows is the power it's receiving. Heck, I could power the drum by dragging a straight plank lined with tire tread over it; now, my device is not using any torque but there's still a torque exerted on the drum. Point being, there's no relation.

[QUOTE]but if you metered the energy put out by the generator you would have the converted equivalent of however much torque you're putting out

cdelena

Huh? Since revs are measured by 'revolutions per MINUTE' and HP is torque times revs, how do you conclude that it is not torque over time?

MattDell

Call me crazy, but this is how I see it:



HP gets the RPMs up, torque spins the wheels.



I could be incredibly wrong about that, but it works in my head.

-Matt

Bieg

Actually RPMs are what gets the HP up.