Power to weight ratio is usually quoted as an absolute. We tend to leave things to the car maker to provide the best gearing to make use of this.
You actually mention CVT in the same breath as peformance?
There is no point in attempting any answer based on inaccurate figures.
If you need an answer to Peter's post, ask him.
But I'll ask you one.
Ignore gearing, tyre widths, weight of vehicle 'kinetic energy' SI units or any one of the many things you seek to confuse with.
Take the engine out of the car and put it on a dynomometer.
Increase the load to the point where engine speed no longer increases or slows down on full throttle. Where do you think that would be?
See my previous post. If you can actually get round the idea of gearing being a red herring for what I stated originally. But somehow, I doubt it.
The answer is straightforward. What is the answer?
I wouldn't expect the engine speed to increase when I applied a load.
Do you accept:
Do you deny: P = F.v = ma . v
or a = P / (mv)
Or is this beyond your abilities?
Rather than snipping this, please explain which bits you don't understand and I'll try and help.
>
Do you accept or deny: P = F.v = ma . v
or a = P / (mv)
Or is this beyond your abilities?
Does that mean you accept "A CVT that holds engine at peak engine torque would be utterly hopeless , making it a lame POS and a mobile obstruction"?
>
Would that be *any* load, then? If so how does any car accelerate?
Tell you what. Just answer my question since you claim to be an expert. No need to find assorted formulae from Google in an attempt to show how clever you are. It doesn't wash here.
Here is is again in case you missed it first time round or couldn't be bothered reading it:-
***********************Take the engine out of the car and put it on a dynomometer.
Increase the load to the point where engine speed no longer increases or slows down on full throttle. Where do you think that would be?
************************If you don't understand the question explain why and I'll try again.
Good try again. You say what you want and leave me to say what I want to.
Once again (not that you'll get it) the gearbox or type is totally irrelevant to the point I originally made. Despite how much you wriggle and quote formualea from Google.
YES! It's way better for outright performance than any automatic, DSG, SMG or stick. It can be programmed to hold the engine on peak power all the time, then it's only a matter of how wide the throttle is open.
As this started out as a comparison of Jag MKII 3.4 and BMW 530i 0-60mph times outright performance is fundamental.
Williams tested a CVT in a F1 car - FW15C. Coulthard was a LOT faster than using gears. It was banned instantly.
Never mind '68, where were you in '93?
We're still waiting.
Try answering a trivial one first that was asked a while ago. It has a simple answer. 1 out 4 possibilities. Even a guess would give you 25% chance of hitting the jackpot.
I recall you claiming torque determined acceleration and not power?
Answer this trivial question:
BMW 530d at 60 mph in 4th, 2315 rpm with 369 Nm (89 Kw) BMW 530d at 60 mph in 3rd, 3300 rpm with 350 Nm (131 Kw).
BMW 530i at 60 mph in 3rd, 3890 rpm with 295 Nm (120 Kw) BMW 530i at 60 mph in 2nd, 5900 rpm with 277 Nm (169 Kw).
Both cars are pedal to the metal on the flat. Which car is accelerating the quickest and which gear does it accelerate quickest in? The one with more power or the one with more torque?
But with vast friction losses which negate any advantages. And then there is the short life.
There are many good reasons why it's died a death - and not before time.
I can't ever remember seeing any CVT figures where the performance was better than the manual equivalent. DSG boxes can, though.
Oh - driving a CVT is just about the most unpleasant experience you can have.
Why are you re-posting someone else's post as your own? Isn't ripping stuff from Google and Wiki good enough for you anymore?
BTW, noted you don't understand how a dynamometer works or what it does in practice. But you claim to know about engine power outputs.
Full credit is given to Peter.
With your engineering degree, hazard a guess to the correct answer.
Is it beyond you?
You don't get it, do you? I'm not going to take any figures given on here as accurate. And simply can't be bothered checking they are. As I'd be very surprised if the figures are easily available.
But given you don't understand BHP and torque and gearing and weight, not really surprising you assume they are correct
You don't get the point, do you?
The answer is trivial and the figures don't have to be accurate to illustrate the point which is quite simply you don't have a clue.
Lots of hub dyno tests here. If makers have published a claimed dyno chart they include that.
But do you understand that Torque is not WORK and doesn't move things?
It takes Work to move things = Force x Distance.
Work 1 Joule = 1 Newton x 1 meter (1 Nm). A vector quantity in the direction of the distance moved.
Torque is a Force (Newton) acting about point at a Distance (meter) from that point and is a scalar quantity (no direction). Yes it has the same
1 Nm dimension as Work but it isn't work.Angular WORK is Torque x radians AND that is what REALLY moves the car.
As Torque isn't work it doesn't and can't move things. I can can make a
1000Nm torque wrench go click with one hand. I can hold that 1000Nm torque on the nut forever, it won't move any more. Not until I do some more WORK either by increasing the torque so it tightens up a bit more or by undoing it. While the nut was rotating as I bought it up to 1000Nm it took some effort as that was Torque x radians and that's WORK. As it took some time I also produced POWER (did it slowly so a rather feeble amount).Just like that nut it ISN'T Torque that moves the crankshaft. It moved by some number of radians so it took Work to move it.
Power is Work / unit time. Joules / second or Torque x radians / second.
That's you all round, isn't it? No accuracy needed. Just quote something you've found online without understanding a single word of it.
You are as daft as fred. A nut doesn't move on a thread when you apply torque. then. A wheel doesn't turn when you apply torque to it.
I'd suggest you put your car up against a solid wall and drop the clutch at maximum 'power'. Does it then 'move'
You've been given 4 choices with precise details of power and torque, speed and gear. You may assume the weights of the cars are the same and any rotating moment of inertia is small such it would not affect the answer.
When you have been given precise details and all the information you require, there is no need for further accuracy.
Once again you show your degree and engineering education to have been worthless.
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