Unknown control lever, heated seat maybe?

[smoothisfast]

Here is Hamilton using it in his imagination. He calls it a brake bias. Start at about 2:15.

http://www.youtube.com/watch?v=StqJ40ro56g

[youtube]http://www.youtube.com/watch?v=StqJ40ro56g[/youtube]

[aussiegman]

I have heard Andrea Stella talking to Alonso over the radio about brake balance though - "Use the rotary if you are out of adjustment with the lever" - indicating some sort of rotary knob to control brake bias.

Brake bias can be controlled by either a lever or a rotary device (which is more common in other categories of motorsport, my 2 cars both use Tilton Rotary bias adjusters).

It is also possible to have both a lever AND a rotary device. One is used for course adjustment (lever) and the other for fine adjustment (rotary).

They will act in different ways to achieve differing levels of adjustment, however work in concert to give immediate high level adjustment when needed and fine incremental adjustments when required.

[marcush.]

I´d think it´s the other way round-lever is sed to switch between two defined Brakebias settings when rotary knob is used to dial in the general front rear brake balance?

[aussiegman]

I´d think it´s the other way round-lever is sed to switch between two defined Brakebias settings when rotary knob is used to dial in the general front rear brake balance?

Apologies maybe my description wasn't clear.

The lever is a defined setting, however it can have more than one setting. So if you move between setting 2 and 3 for example on the lever (which may adjust a number of variables in relation to braking or chassis balance) the rotary adjustment will let you dial in as an example 2.5 or any other fractional percentage between 2 and 3.

As the lever will typically have a predetermined number of gates of movements set at evenly spaced percentages and as such it allows only "course" adjustments (as an example 5 stages accounting for 20% per gate of total adjustment or 2 gates. Pick any variable) while the rotary adjustment in theory can have an infinite number of adjustment stages throughout its 360 degree rotation or more depending on adjustment ratio.

It is even possible to have differing rotary ratio's where requested/required that necessitates a lesser or greater number of turns to achieve any given percentage of adjustment to increase or decrease adjustment sensitivity. Some drivers may like greater control, other may feel simple course adjustments are all that's required.

Series other than F1 (which I have been party too) used similar setups, so I am simply surmising that this is what "might" be happening here. I don't know definitively if this is the case.

[bhall]

Here is Hamilton using it in his imagination. He calls it a brake bias.

Though he's calling it that, it's not brake bias. As far as I know, that control cannot be on the steering wheel, because...

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 driver's direct physical input, may not be pre-set and must be under his complete control at all times.

[hardingfv32]

1) A valve type brake adjuster normally just restricts pressure to one half/leg of the system. There is no actual redistribution of 100% of the applied braking effort. The use of this type of a valve means the lose of some of the driver's application force. Has anyone ever seen a brake bias 'valve' that preserves 100% of the application force?

2) A traditional brake bias bar system has a threaded shaft requiring a rotary action to change the bias. Has anyone ever seen a system that used a stepped linear motion that was actuated directly by the driver?

Brian

[bhall]

via Scarbs

(Click to enlarge)

And in what might be a first for PaulB's paper Red Bull...use as evidence. (If it's there, it's there.)

(Click to enlarge)

[smoothisfast]

Though he's calling it that, it's not brake bias. As far as I know, that control cannot be on the steering wheel, because...

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 driver's direct physical input, may not be pre-set and must be under his complete control at all times.

did you watch the video? he moves his left hand down off the wheel to an imaginary lever and calls that the brake bias.

[bhall]

Nope. I didn't watch one second of it. I thought I'd seen it before.

Sorry about that.

EDIT: Worth a down vote? This is going to be fun.

[marcush.]

so your estimate is the thing on the left is a proportion valve and the knob is a balance bar adjuster ? in "normal" race cars
I´d say right but in Formula 1 ? I would not discount the possibility this lever actually is a hydraulic device altering the balance bar setting.

[hardingfv32]

The upper photo above is a proportion valve.

I have never seen an example of a hydraulically operated brake bias bar. I could imagine a two position system, but not an infinitely adjustable system.

Brian

[aussiegman]

The upper photo above is a proportion valve.

I have never seen an example of a hydraulically operated brake bias bar. I could imagine a two position system, but not an infinitely adjustable system.

Brian

From the photo's above, the adjustment level appears to have three (3) or at least three (3) adjustment settings that act directly on a proportioning valve as evidences by the pin locking mechanism.

You could in theory construct an infinitely adjustable proportioning valve with a screw adjustment, however as Brian has said, they are typically not infinitely adjustable as this is defined within the brake bias bar at the pedal/cylinder level.

[autogyro]

Current F1 system for brake bias makes it next to impossible to balance with energy harvesting and deal with tyre deg.
I cannot see a workable way out of this with the current powertrain layout.

[Lycoming]

why is that? the power (ie. the rate of energy capture) of the MGU when harnessing never changes unless you change the harvest setting on the steering wheel. The amount of energy stored is a different matter; excess energy is dumped through some big resistors.

By playing with the harvest and brake bias knobs, you can easily maintain the balance between front and rear braking power constant at whatever level you like, so I don't see why you can't balance the two and deal with tyre deg.

[autogyro]

why is that? the power (ie. the rate of energy capture) of the MGU when harnessing never changes unless you change the harvest setting on the steering wheel. The amount of energy stored is a different matter; excess energy is dumped through some big resistors.

By playing with the harvest and brake bias knobs, you can easily maintain the balance between front and rear braking power constant at whatever level you like, so I don't see why you can't balance the two and deal with tyre deg.

Add engine overrun braking through a sequential stepped layshaft gearbox with the MGU mounted on the crank nose.
The whole lot having to work with a downforce components capable of slowing the car with at least one G when you lift off.
If they get it even slightly wrong I am surprised that it doesnt rip the treads off the tyres.

A bit like trying to control an aircrafts roll with wing warping.
Nowhere near the best way to do it.