18 replies to this topic

[flymo]

Hi, just curious about the comments credited to Mr. Villeneuve yesterday, in which he indicated that he would need to change his driving style to accommodate the differences in the Sauber's suspension and in "the electronics for the brakes".

Does anyone know what aspect of the braking system is under electronic control? Is there servo assistance, some kind of automated bias adjustment, antilock control? I thought the rules kept the brake systems relatively simple.

[xflow7]

I wondered that, too. I'm sure they're not allowed automatic brake bias control or antilock. Not sure about power assist.

Having said that, it's possible that the bias adjustment is allowed to be electronically controlled, provided the control input comes from the driver (similar to the rules about diffs.) with the driver adjusting between corners or the like. If that is the case then one thought I had is that perhaps the response curve of the bias control is such that it is very different to what Jacques is used to, but somehow I don't see that as being something particularly difficult for a driver to adjust to, so I doubt that's it.

Anyhow, the actual regs are easily checked. I think all the tech regs are posted at formula1.com. Haven't gone to look at them yet, though.

In any case, I did find the comment strange.

[xflow7]

From www.formula1.com,

ARTICLE 11: BRAKE SYSTEM
11.1 Brake circuits and pressure distribution:
11.1.1 All cars must be equipped with only one brake system. This system must comprise solely of two separate hydraulic circuits operated by one pedal, one circuit operating on the two front wheels and the other on the two rear wheels. This system must be designed so that if a failure occurs in one circuit the pedal will still operate the brakes in the other.
11.1.2 The brake system must be designed in order that the force exerted on the brake pads within each circuit are the same at all times.
11.1.3 Any powered device which is capable of altering the configuration or affecting the performance of any part of the brake system is forbidden.
11.1.4 Any change to, or modulation of, the brake system whilst the car is moving must be made by the drivers direct physical input, may not be pre-set and must be under his complete control at all times.
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.
11.4 Air ducts:
Air ducts for the purpose of cooling the front and rear brakes shall not protrude beyond:
- a plane parallel to the ground situated at a distance of 160mm above the horizontal centre line of the wheel;
- a plane parallel to the ground situated at a distance of 160mm below the horizontal centre line of the wheel;
- a vertical plane parallel to the inner face of the wheel rim and displaced from it by 120mm toward the centre line of the car.
Furthermore, when viewed from the side the ducts must not protrude forwards beyond the periphery of the tyre or backwards beyond the wheel rim.
All measurements will be made with the wheel held in a vertical position.
11.5 Brake pressure modulation:
11.5.1 No braking system may be designed to prevent wheels from locking when the driver applies pressure to the brake pedal.
11.5.2 No braking system may be designed to increase the pressure in the brake calipers above that achievable by the driver applying pressure to the pedal under static conditions.
11.6 Liquid cooling:
Liquid cooling of the brakes is forbidden.

Now in a thread a while back somebody made a post to the effect that the engine electronics manipulated engine throttle, etc. to prevent the rear wheels from locking under braking. I replied asking if this was legal as it could be construed as anti-lock, however I don't think we ever resolved this grey area.

Above the rules clearly say "No braking system may be designed to prevent wheels from locking when the driver applies pressure to the brake pedal."

However, what they don't address explicitly is whether another "system" (i.e. engine management) can influence braking performance. If one takes the liberal interpretation, then it is conceivable that, in fact, one is allowed to effectively modulate rear-wheel slip even while braking modulation remains under driver control. So, perhaps there is a system like this in place, and that is what JV is commenting on.

[naiboz]

so the engine could keep enough force going to the rear wheels to stop them locking?

[desmo]

I would assume after reading the regs that the top teams at least almost certainly use engine torque against braking to provide on the fly active brake bias adjustment, and very probably for rear wheel ABS as well. None of this is in my opinion in any way prohibited by the Technical Regulations as published. Of course the vast bulk of the regs are secret in the form of "clarifications", so one never knows.

[xflow7]

Originally posted by desmo
I would assume after reading the regs that the top teams at least almost certainly use engine torque against braking to provide on the fly active brake bias adjustment, and very probably for rear wheel ABS as well. None of this is in my opinion in any way prohibited by the Technical Regulations as published. Of course the vast bulk of the regs are secret in the form of "clarifications", so one never knows.

Agreed.

[Wuzak]

Originally posted by xflow7
Anyhow, the actual regs are easily checked. I think all the tech regs are posted at formula1.com. Haven't gone to look at them yet, though.

Why not go to "the horse's mouth" at www.fia.com ?

[xflow7]

Originally posted by Wuzak


Why not go to "the horse's mouth" at www.fia.com ?

Did you happen to notice the post immediately after the one you quoted?

[ME]

I started a thread a while back with regards to the rear abs, but I think it was resolved to be somewhat implausible due to insufficiant time in each individual gear.

http://forums.atlasf...&threadid=20174

As for JV's comments I'm sure he wouldn't be referring to any illegal system to the press, at least i hope thats not the case
I'm sure it has to do with the brake balance controls on the wheel itself, i'm positive brake bias is controlled electronically. So it could be possible he's not used to the format the team uses (to touchy, not touchy enough, turns the wrong way, etc... ).

[red300zx99]

though brake bias couldnt be controlled by electronics, as it constitutes a powered device. Therefore bias adjustment is a conventional manual piece

[ME]

When I said electronically I don't mean automatically, or computer controlled or anything, so possibly I should have said electrically modulated or something along those lines.
I am just basing this on the fact that I'm almost positive most teams control their brake bias from a dial on the steering wheel. Now given the fact that these wheels are quick release, it would make more sense to electrically control a hydraulic valve than have some Obscure hydraulic connections to the wheel. By the way I might be wrong here, i'm just making it up as i go along. I hope this makes sense!

[Pioneer]

Originally posted by ME
I am just basing this on the fact that I'm almost positive most teams control their brake bias from a dial on the steering wheel.

You'd be wrong... its a mechanical knob usually on the dash.

The regulations demand it to be thus.

[ME]

I don't know about that, unless the rules have been totally revamped since these articles have been written. Here are some examples, and links to the articles:

http://www.formula1....nfo/11/645.html

while rotary controls govern functions with multiple settings, such as the traction control programme, fuel mixture and even the car's front-to-rear brake bias - all functions the driver might wish to alter to take account of changing conditions during the race.


This one is actually pretty good, it has a pic of a Ferrari wheel, with buttons labeled.

http://www.indiacar....al/steering.htm

Two further buttons, often located at the top of the steering wheel either side of the digital display, will control the brake balance bias front to rear. Press one button to give yourself more front bias. Press the other button to give yourself more rear bias. Some teams also use a very high-tech electronic control for the brake balance system, which automatically puts more bias to the front brakes when the pitlane limiter is pressed. Then, once the button is no longer de-pressed, the balance will automatically unwind to a pre-agreed setting ideal for that particular circuit. Usually the driver will require more rear bias on the circuit than he would ideally like for stopping in the pit lane.


Here is a drawing of a williams wheel with a "brake systems control" button on it.

http://f1.allianz.co...kon_lenkrad.jpg

So... I could find some more examples!

[scarbs]

Does he mean engine braking on the over run which is electronically controlled.
But rear wheel ABS is partially achived with the fly by wire throttle. This is admitted by the teams

[red300zx99]

One would think the FIA wouldn't allow the brake bias to be controlled by an electirc knob, giving way to electronic trickery there. So I pose this question, if it's on the wheel what has MS been crankin on under the dash for the past couple of years?

[Pioneer]

Radio station?

[zac510]

lol Pioneer

I read an interview with a Ferrari engineer a few years ago, I cannot remember which one but it might have been Brawn. He mentioned that the rules did not allow the brake bias to be changed while the car was braking. So then of course the driver just tweaked the bias before he got to the braking point
However I think this must have changed in the last few years as I see nothing in Article 11 that would allow this.

[alfa1]

I was just looking over the videotape of last years Melbourne GP qualifying , and Webber was featured doing a rundown of the controls on his (Jaguar) steering wheel.

Of relevence to the original question on this topic, Webber described:
- The differential control knob, which he said affected braking
- The EB control knob, which controlled engine braking
- The brake balance button(s)? on the steering wheel. It seems brake balance has to be a mechanical device, but it is permitted to set the position of that mechanical device by the driver using simple electronic controls?

[random]

As Desmo and Scarbs point out, Jacques is almost certainly talking about engine braking. All the teams seem to use engine torque to slow the cars in a controlled manor. Even though it doesn't use the brakes, it slows the car. Effectively, it is rear wheel ABS.