Is Power (rwkw) Figure Everything? Why Are People So Hung Up On Kw Figures

[jarrod83]

the speeds in mph, liking the 900Nm of torque by 2500

[ARTZ]

this is where its @

engine dynod first then into the shop on the dynapack.... no bullshit "roller derived tractive effort" figures... just look at the torque (cold hard real torque).... i can tell you now nothing compares to driving something with this much horsepower and torque... and this is a daily driver, that returns 10-14l/100km

So what you trying to say here is the engine dyno gave the same results as the dynapack?

Or are you just flexing your e-wang ya show off......

[PM-R33]

I still want to know what car it is!

[ARTZ]

ill put 10$ on toyota

[Harey]

Ok so assuming a 1000rpm drop of changing up gears, when would you change gears on this monster car?

If your about torque then I would predict just above 5,000rpm and if your about power then around 6,500rpm.

[Rolls]

Ok so assuming a 1000rpm drop of changing up gears, when would you change gears on this monster car?

If your about torque then I would predict just above 5,000rpm and if your about power then around 6,500rpm.

Well if you thought that torque was the key to a fast car you would shift to maintain max average torque over the rpm range, and do the same for horsepower, obviously shifting to maximise max horsepower over the rev range makes a car faster, not peak torque.

[Harey]

You must read this thread: http://www.allpar.com/eek/hp-vs-torque.html

I think that solves all the issues.

[Rolls]

You must read this thread: http://www.allpar.com/eek/hp-vs-torque.html

I think that solves all the issues.

we have already come to a conclusion and I believe everyone is happy they understand it, to maximise performance you want to shift at peak power and keep peak power under the curve, not peak torque under the curve, are you saying this is incorrect?

edit: that link says the same thing, so I'm assuming you are in agreeable with everyone?

Edited November 9, 2010 by Rolls

[Harey]

we have already come to a conclusion and I believe everyone is happy they understand it, to maximise performance you want to shift at peak power and keep peak power under the curve, not peak torque under the curve, are you saying this is incorrect?

edit: that link says the same thing, so I'm assuming you are in agreeable with everyone?

Yup I am agreeing. I just think its a really good comprehensive explanation of it.

[Rolls]

Yup I am agreeing. I just think its a really good comprehensive explanation of it.

it really is, good find.

[jarrod83]

That was an awesome explanation of the problem.. its funny how he summed up so many points me n rolls covered.. with the whole cvt etc,

and this bit

"Hmmm... P = F * V ...rearrange to get F = P / V ...

that means that you get the maximum force pushing the car if you maximize your *Power* at any given velocity. This gives us another useful rule:

Shift to maximize engine POWER, not engine torque!"

funnily enough i had to use all these formulas for my exam today, except i had to calculate the maximum power i could get a car to produce at 80kmph and the equivalent engine rpm with different gears and the diff, subtract the drag power loses, then calculate the maximum hill gradient the 1800kg car could cruise up, P=mg sin(hill angle) * velocity ftw