Theoretical (physical) limits of F1 car

[marekk]

Looking at this picture of drag racer starting to flip over

i started to wonder - where are physical limits of F1 car, before it starts to do the same (probably in lateral direction at first).
What do you think ?

[747heavy]

without downforce, and some guesstimates in terms of CoG height, wheelbase and trackwidth
I would venture out and guess:

~ 7.5 g longitunal accel.
~ 4 g lateral accel.

[delacf]

Limits? v<c

With the actual regulations?

Regards,

delacf

[marekk]

Limits? v<c

With the actual regulations?

Regards,

delacf

I meant how far we are at the moment from real (physical) limits. For example, granted tire friction limits are above our longitudal/lateral forces, what cornering speeds are possible with current F1 car ?
(And looking at current nanotechnology development, we are not that far from a tire with practicaly unlimited traction, so it's not just theoretical question)

[Tim.Wright]

The cars are already operated very close to the tyres limits. You won't ever have a tyre with unlimited friction so I don't understand your question.

tim

[marekk]

The cars are already operated very close to the tyres limits. You won't ever have a tyre with unlimited friction so I don't understand your question.

tim

There will be no unlimited friction ever, but let's say we manage in next 5 years to get 10 times better friction coefficient then current generation of rubber compound based racing tires.
No science fiction - just take a look at this link http://www.sciencedaily.com/releases/2007/06/070619083554.htm

[Tim.Wright]

well in that case the limits would be as 747h said, but modified to include downforce. Though such an increase is still science fiction for now.

[marekk]

well in that case the limits would be as 747h said, but modified to include downforce. Though such an increase is still science fiction for now.

Tim,
belive it or not, it's no more science fiction at all.
It's not mass production ready yet, but it's a question of time:


But going back to my question:
What will be physical speed limit for a current spec's F1 car with my almost unlimited friction tire's at let's say silverstone's Stowe corner (just before car starts to flip over)?

[Ciro Pabón]

Hmmmm.... Theoretical.... one of my favorite words. No regulations either. We all know that there are no regulations for Formula One races in Theoreticland.

First, wheelies.

So, we're speaking of 750 HP and 100% efficiency (well, 99.9%, before a theoretician in physics points out the error).

At 18000 rpm we have... what? 18*2*pi/60 kilorads per second. As 750 Hp are 750 * 745.7 watts, we should have a torque at the rear wheels when you launch your car of (750HP*745.7watts/HP)/(18000RPM*2*pi/60seg/min) which is 297 newtons-meter. Pretty puny, as this means 218 pounds-feet for the Anglophiles.

With misserable 300 newtons-meter and as the car has a COG that (let's say) is 2 meters ahead of the wheels, you can exert a force of 150 Newtons.

No, you cannot do wheelies in a Formula One unless some smart person discover where I made I mistake.

We already knew that the torque of an 18.000 rpm engine sucks.

Second, the perfect adherent tyres.

The gecko raises a more interesting question, as the acceleration is limited only by the tensile strength of the fibers in its feet that somehow "hook" from the ceiling. If you are not using friction but effectively hooking yourself to the surface, tyres are radically different.

If that's the case, then the theoretical limit would be to have as many hooking fibers in the tyres as you need to completely cover the patch area. This means that you are essentially welding the tyre to the tarmac. So, the limit would be the strength of the tyre "material". It's exactly like using a centrifuge with a solid axle.

As (I think) Kevlar is the material with the highest tensile strength per weight, let's imagine Gecko feet made of kevlar, that adheres perfectly to the tarmac using a technology yet to be developed.

Then, as carbon fiber weighs 1440 kilograms per cubic meter and has a tensile strength of 3620 Megapascals, which is the same as 3620 million Newtons per square meter, this means you need an acceleration of 3620 million N/m2 / 1140kg to break one of those fibers by its weight alone. This is 2.5 million meters/seg2 or around 250.000 g.

In English, this is a quarter of a million times the force of gravity.

So, if you are taking a curve at 300 kph and you use the full potential of your "tyres", you could take curves with a radius of 2 millimeters. Those are not tracks, but more like railroads.

This would make for, perhaps, boring circuits, as the straights would have no curves between them. A tad boring, except for the disintegration of the drivers after taking the first curve at 250000 g.

[marekk]

Hmmmm.... Theoretical.... one of my favorite words. No regulations either. We all know that there are no regulations for Formula One races in Theoreticland.

So, we're speaking of 750 HP and 100% efficiency (well, 99.9%, before a theoretician in physics points out the error).

At 18000 rpm we have... what? 18*2*pi/60 kilorads per second. As 750 Hp are 750 * 745.7 watts, we should have a torque at the rear wheels when you launch your car of (750HP*745.7watts/HP)/(18000RPM*2*pi/60seg/min) which is 297 newtons-meter. So, as the car has a COG that (let's say) is 2 meters ahead of the wheels, you can exert a force of 150 Newtons.

No, you cannot do wheelies in a Formula One unless some smart person discover where I made I mistake.

We already knew that the torque of an 18.000 rpm engine sucks. I call them "electric sharpener engines".

I've always respected the sound of an NHRA engine... on the other hand, finally I have a reason to understand why I do NOT like the sound of a Formula One engine. Please, spare me the nagging, will ya?

I belive they'll use some gear box and differential between this engine and wheels.
But i'm wondering more on limits from lateral forces in corners.

[Ciro Pabón]

Sorry, I edited the previous post after writing on wheelies to include the lateral acceleration you could pull with current materials that adhere perfectly, in theory.

I guess that 250.000 gs is the top acceleration you could get from a perfectly adherent tyre. At 320 kph you could do curves of 2 mm radius, theoretically speaking.

Oh, and no differential can change the amount of torque you have. By using a gearbox you can change the acceleration of the car, but not the torque.

[Tim.Wright]

So, we're speaking of 750 HP and 100% efficiency (well, 99.9%, before a theoretician in physics points out the error).

At 18000 rpm we have... what? 18*2*pi/60 kilorads per second. As 750 Hp are 750 * 745.7 watts, we should have a torque at the rear wheels when you launch your car of (750HP*745.7watts/HP)/(18000RPM*2*pi/60seg/min) which is 297 newtons-meter. Pretty puny, as this means 218 pounds-feet for the Anglophiles.

With misserable 300 newtons-meter and as the car has a COG that (let's say) is 2 meters ahead of the wheels, you can exert a force of 150 Newtons.

No, you cannot do wheelies in a Formula One unless some smart person discover where I made I mistake.

There must be something wrong. 150N is 15kg, which is far too low for an acceleration force. I dont understand what the distance of 2 meters has to do with anything. From the torque at the wheels, you need to divide by the wheel radius which is approx 300mm. But what you have calculated is the torque at the engine flywheel. You need to multiply this by the gear ratio of the gearbox and diff to get the wheel torque.

Anyway, what you are trying to prove is correct. There is not enough engine power to make an F1 car do a wheelstand

tim

[marekk]

Sorry, I edited the previous post after writing on wheelies to include the lateral acceleration you could pull with current materials that adhere perfectly, in theory.

I guess that 250.000 gs is the top acceleration you could get from a perfectly adherent tyre. At 320 kph you could do curves of 2 mm radius, theoretically speaking.

Oh, and no differential can change the amount of torque you have. By using a gearbox you can change the acceleration of the car, but not the torque.

Final drive and gear box ratio do not change the torque on wheels ?
And the car would not flip over to the outside in 2mm radius corner ?
I'm wondering even more then before.

[marekk]

without downforce, and some guesstimates in terms of CoG height, wheelbase and trackwidth
I would venture out and guess:

~ 7.5 g longitunal accel.
~ 4 g lateral accel.

And with downforce ?
I've read that actual F1 cars have been recorded with lateral acceleration in excess of 6g at Suzuka.
It's 8-9g (and resulting blackout) possible ?

[747heavy]

at the time, I think 130R (Suzuka) was flat out, therefor power limited.

IMHO - with free engine, tire and chassis/downforce regs blackout would be possible and the driver would probably beeing the "limiting factor" -
driver blackout before lateral roll over.

IIRC there where "grey out" situations in Indycar (IRL/Champcar ? - not sure how it was called at the time), a couple of years ago at some of the ovals.