Let's Torque about Ponies...story included...so its long

[^_^civic^_^]

G'day fellas!

So this is my first post yea, it's a bit long, but please bare with me...its more like a kinda experience as well as a discussion about the age old debate between torque and ponies...plz don't flame me if this is the wrong forum :(

So what's the go then? which is more critical when it comes down to a drag? Power or torque? I know that if we got two identical cars in weight and gearing, then the car with more power accels faster. Power to weight ratios of course. And the car with greater torque will jump off the line quicker...BUT

What if there are two cars: Both have identical power, but one car is fair bit heavier than the other (150-200kg more) and carries a fair load more torque (say 80nm more). Now obviously the power to weight ratios show the lighter car at an advantage. But I was thiking, because of the extra torque, especially on uphills, then the torquier car should accelerate better (?) or draw even at least. Or am I wrong in thinking so?

Does the torque more than make up for the power to weight deficit?


BTW, edited it just then cos of the whole no illegal street racin rule ^_^ PEACE!

[D16Y]

rs's are 2.5Ls

[zco]

ever thought about driver skill and who had a better start. read the forum rules. we dont wanna hear about your street racing stories

[^_^civic^_^]

yea...i kinda just stumbled across that whole no street racin posts thingy...my bad...shoulda looked it all up b4 postin

and yea...2.5L, missed that

[bennjamin]

remember - no illegal on-street drag talk thanks.

what is the point of this thread btw ?

[aaronng]

All the talk about power and torque is moot. Because power is not a measurable figure, but rather a number calculated from your torque at a particular RPM that would give the highest value. So, in the end, if 2 cars are exactly identical, with identical drivetrain, weight and driver, both with same power but one with huge torque at low rpm and the other with lower torque at high rpm, both would be equally as fast once there is enough distance covered.

If you want figures to give you a real performance estimate, dyno both cars, get the dyno plots of the power curve, and measure the area under the curve for each gear in the RPM ranges that will be involved. The one with the largest area (work) in a set amount of time wins.

[^_^civic^_^]

That's a pretty cool insight there aaronng. I neva thought about it that way. But still, if you do the math, you'd need to consider the weight of the vehicles. So inotherwords, weight would still be a major factor.

So i'm thinkin, inorder to overcome the weight deficit, torque is required. So if you had enough torque, shouldn't you be able to make the acceleration better?

I'm thinkin that by increasing torque, accel can improve up to an extent only, where at which point, the power becomes the limiting factor, and to further increase accel, more power would then be required.

Hmmm, so yea, a huge power car with jack all torque...bad obviously, but compared to a car with the same power but double the torque? How would that be?

[aaronng]

That's a pretty cool insight there aaronng. I neva thought about it that way. But still, if you do the math, you'd need to consider the weight of the vehicles. So inotherwords, weight would still be a major factor.

So i'm thinkin, inorder to overcome the weight deficit, torque is required. So if you had enough torque, shouldn't you be able to make the acceleration better?

I'm thinkin that by increasing torque, accel can improve up to an extent only, where at which point, the power becomes the limiting factor, and to further increase accel, more power would then be required.

Hmmm, so yea, a huge power car with jack all torque...bad obviously, but compared to a car with the same power but double the torque? How would that be?
In my explanation, weight was equal. For your huge power car with jack all torque vs same power car but with double torque, it means your first car can rev to twice the rpm of the 2nd car. If their weights are the same, then after a certain distance, both cars will have the same speed. First, the car with heaps of torque will accelerate harder and go first. Then he will have to shift because his engine doesn't make enough torque to sustain acceleration at redline. When he shifts, the 1st car is still in first gear and is through 1/2 his rpm range (or even less!) He saves time on shifting, and is still not at the top limit of the rpm yet. This is when he will catch up.
When both cars have finished using 1st gears, they would be using only the top of their rpm range. Assuming car 1 uses 8000-12000rpm and car 2 uses 4000-6000rpm (with car 2 having double torque, but both cars same power). With both having the same gearbox, I think the rpm drop should about there. Notice that Car 1 will be using 1 gear lower than car 2, and car 1 has a wider RPM range to use in each gear.

[Lonewolf]

basically, torque deficiencies can be made up with gearing, power cannot.
If we all drove around with 1spd gearbox's torque would be all that matters.