F1 Braking at high speeds.

[Caito]

Hello guys, a doubt recently generated in my mind.

F1 cars have no ABS. I haven't seen any car block the wheels at high speeds, from this I arrive to the conclution that the brakes are not powerful enough( with high downforce ) to block the brakes. Else we would see ocassional wheel lock, as it happens when they trailbrake(low speed) to the corners, locking the inner front wheel.

If this is true, stopping is determined by the strength of the driver? Seems doubtful. If they need more force why don't they put bigger caliper pistons( constant pressure, Force=P.A, high area, higher force), or smaller brake piston( Smaller area, larger pressure P=F/A) of course this would require larger fluid displacements, more pedal movement.

Since I know F1 mechanics are not stupid, it can't be as simple as that. So I think they might not do it to avoid overheating the brakes.

Can anyone help me clarify this point? What's the limiting factor in an F1 car braking at high speeds?


Thank you very much, bye bye!

Caito.-

[ahmedvortex]

the limit of the braking power is the driver himself , they cannot handle more than 7 g , now the max braking power added with the down force reach 5g one the top cars .

[speedsense]

It is far easier for the driver to keep from locking the wheels on initial braking "strike" due to the aero drag also braking the car. It is after the aero starts to bleed off that you see a brake lock, as the aero changes the braking bias, not mechanically but aero wise.
It not that they can't lock the brakes with the aero, just the added force that they can add due to aero "braking". IMHO

[Just_a_fan]

The brakes are limited by the Regs:

11.2 Brake calipers:
11.2.1 All brake calipers must be made from aluminium materials with a modulus of elasticity no greater than 80Gpa.
11.2.2 No more than two attachments may be used to secure each brake caliper to the car.
11.2.3 No more than one caliper, with a maximum of six pistons, is permitted on each wheel.
11.2.4 The section of each caliper piston must be circular.
11.3 Brake discs:
11.3.1 No more than one brake disc is permitted on each wheel.
11.3.2 All discs must have a maximum thickness of 28mm and a maximum outside diameter of 278mm.
11.3.3 No more than two brake pads are permitted on each wheel.

from http://www.formula1.com/inside_f1/rules ... 1/fia.html

The current designs are probably at the limit of what the system can do so the retardation is probably brake limtied. I suppose one could say that the system is limited to what the driver can put in to the brake pedal but if that were the case, I would expect to see varied braking rates across the field which isn't obvious from the info we have available.

The driver could handle higher decelerations if required but they must be close to what can be borne in terms of driving the car whilst braking (the current time under braking is fairly short so reducing it further and expecting the driver to stay on top of the car whilst defending / attacking etc. might be asking too much).

The downforce at top speed is likely to be sufficient to allow more inital braking if the system could deliver it but only for a fraction of a second - downforce being proportional to the square of the speed.

The current braking curve is probably as close to the optimum in the time available. Adaptive rear aero might help slightly but I doubt they'll tune the system to help with braking if it is at the expense of performance elsewhere.

[timbo]

11.2 Brake calipers:
11.2.1 All brake calipers must be made from aluminium materials with a modulus of elasticity no greater than 80Gpa.

That one.
The force applied by brakes are limited by caliper stiffness.

[adam2007]

how do you see the orange glow when the disks are covererd up????

[omar2726]

F1 cars have no ABS. I haven't seen any car block the wheels at high speeds, from this I arrive to the conclution that the brakes are not powerful enough

If you watched the episode of Top Gear wherein Richard Hammond tried out the Renault R25, you would notice that he kept on locking the wheels during braking. I think that it is not only an issue of the brakes not being strong enough for them to lock, but it's also based on driver skill to get the maximum braking power without locking, like threshold braking.

Somebody correct me if I'm wrong :

Cheers

[xpensive]

Perhaps what is limiting braking-force at higher speeds is power-dissipation. When power is force times speed, braking-force can be four times higher at 80 km/h than at 320 for the same power, while power at Spa can be more than 2300 kW.

[timbo]

power-dissipation

Ain't that cheesy sounding a bit?

[xpensive]

According to Brembo, there's a braking zone at Spa where the car goes from 328 (91) to 167 km/h (46 m/s) in 1.40 sec, which gives an average of 3.25 g with a peak of 5.06 g. Braking power is 2350 kW, which, if equal during the entire sequence, means that braking force goes from 25.8 to 50.6 kN

[timbo]

Braking power is 2350 kW, which, if equal during the entire sequence, means that braking force goes from 25.8 to 50.6 kN

I don't doubt the data.
I just noted that power is not a "quantity" and cannot be stored or dissipated. Although I looked in the web and it seems it is pretty wildly used.
Still it doesn't sound right to me.

[Tim.Wright]

brake power dissipation is the power converted from kinetic energy to heat energy. Its not destroyed.

Tim

[Just_a_fan]

Perhaps "heat dissipation" is better?

Or "braking power" which nicely points out that braking is a way of doing work (albeit not very useful work unless you think heating a piece of carbon by several hundred degrees is useful )

[timbo]

brake power dissipation is the power converted from kinetic energy to heat energy. Its not destroyed.

Tim

Um, you can't convert "power" from "energy".

Perhaps "heat dissipation" is better?

Or "braking power" which nicely points out that braking is a way of doing work (albeit not very useful work unless you think heating a piece of carbon by several hundred degrees is useful )

Both sounds better to me than power-dissipation.

[Sean H]

how do you see the orange glow when the disks are covererd up????

the face of the rotors aren't covered, the shrouds direct airflow through the vents of the rotor.