More torque at the wheels?

[jcorsico]

All of the TV announcers are discussing how hard the 2014 cars are to drive because the new engines put out more torque. However, this statement would only be true if the cars actually had more torque at the wheels (i.e., more force between the rubber and the road, which would make the tires slip more).

Torque at the wheels is determined based on the entire drive train, and is heavily influenced by the gearbox. A high HP low torque engine (like the old V8s) can generate tons of torque at the wheels if you use the right gearing.

So - what's the deal with the 2014 cars? Is there actually more torque at the wheels? Or, are the drivers just struggling because they have less rear down force (and the tire composition is different too)?

Thanks
Jon

[Holm86]

There is not more torque at the wheels no. The lower RPM's and gearing offsets this so the maximum torque at the wheels are around the same as with the V8's.

The big difference is that there is a higher torque level accessible over a broader rev band. So the power delivery is not as progressive as with the V8's and much more instant. This causes the tires to slip easier.

[Roland Ehnström]

I see your point, but the comments I've heard from the drivers themselves suggest that they do indeed have a lot more torque at the wheels at the critical part of the exit of the corner. They also have less grip than before.

[hollus]

...more torque at the wheels at the critical part of the exit of the corner...

That is right, at the critical part of the corner, where they start to accelerate from wherever they were after applying variable throttle, which means at low revs. The new engines have a flatter power curve and more power at low revs.

More power at low revs = more torque at the wheels at low revs.



Now you have more power (read torque at the wheels) for a larger part of the acceleration phase.

[mrluke]

The new cars have pretty much the same power (and torque) across the whole rev range, the old v8s only made this power right before they changed up a gear. Effectively this meant that last year when the drivers put their foot to the floor the engine progressively put more load onto the tyres, whereas now it just throws everything at them.

[Dragonfly]

I may be wrong but when drivers speak about more torque it seems to me they refer to feeling greater pulling force. Which is a subjective perception.

[dren]

I may be wrong but when drivers speak about more torque it seems to me they refer to feeling greater pulling force. Which is a subjective perception.

It's like launching your own car at redline. The wheels spin. That power was always there, you just normally rev the engine up to get to that point. Now, when the drivers press the pedal, that power is already available because the power curve is so flat. See the nice graph above.

[machin]

http://i.imgur.com/pMHl9vv.jpg

What magazine was that from?

[hollus]

Race engine technology #72 and #73. Originally posted in the intercooling thread:
http://www.f1technical.net/forum/viewto ... 42#p478542

[SectorOne]

But surely the maximum torque output of the engines can be completely different?
I mean two engines with a max power output of 500 horsepower can still have vastly different maximum torque outputs?

For example the old V8, not a very torquey engine. Probably produces around what 300 Nm of torque at most?
While you can have a car with the same horsepower but a torque output of over 1000 Nm.

I also notice the graph only shows horsepower and doesn´t show the torque curve.

Like this,

[mrluke]

The drivers talk about the "pulling force" what they are referring to is actually the "rate of change of acceleration" also known as Jerk.

[langwadt]

But surely the maximum torque output of the engines can be completely different?
I mean two engines with a max power output of 500 horsepower can still have vastly different maximum torque outputs?

For example the old V8, not a very torquey engine. Probably produces around what 300 Nm of torque at most?
While you can have a car with the same horsepower but a torque output of over 1000 Nm.

I also notice the graph only shows horsepower and doesn´t show the torque curve.

Like this,

http://www.sjmautotechnik.com/trouble_s ... c/a8v8.jpg

power is torque times speed, ( P = torque*RPM/60*2*pi)

so if two engine makes the same power, one with 1000Nm and the other with 300Nm, the 300Nm engine must spin 1000/300 times faster so drive the same speed it must have 1000/300 times lower gear which then makes the torque at the wheel the same.

[SectorOne]

so if two engine makes the same power, one with 1000Nm and the other with 300Nm, the 300Nm engine must spin 1000/300 times faster so drive the same speed it must have 1000/300 times lower gear which then makes the torque at the wheel the same.

So every single piston engine in the world produces the same amount of torque on the wheels?

[Richard]

Yes, if matched with the right gear ratios. As Archimedes said "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world." It's just the same for a tiny engine with an appropriate gearbox, albeit with very little displacement !

It really is a simple as Power = torque * speed. If you can change the speed then you can have any torque you want. Of course extreme cases are hypothetical because inertia, tolerances and friction will mean a tiny engine would be unlikely to turn the gearbox.

[machin]

It really is a simple as Power = torque * speed. If you can change the speed then you can have any torque you want.

And if the speed is held constant (e.g. two cars with equally sized wheels are travelling at the same speed) and the two cars have the same power, they will also have the same torque at the wheels, regardless of what the torque at the flywheel is.