Clutch Kiss point

[marcush.]

but sure this is different ..ok the steering is hydraulic assist ,the brakes are hydraulic ..you definitely have a feedback of forces there ..with throttle or the clutch actuation it is just the reactions of the car you get but not the in ln the loop force feedback on the lever ...

[WhiteBlue]

Hmm. I just can't imagine that there is enough feel or range of motion in a steering wheel paddle for a driver to control confidently.

The clutch levers on the steering wheel do nothing but activate the preset launch torque and full torque later. They are simple binary switches and do not have a proportional range like the clutch pedal in a stick shift car. If the preset torque is badly selected or the clutch disks are damaged and have different frictional properties than anticipated the launch will be bad. With too much torque the engine can get bogged down and the driver has to de clutch again. That happened to Sebastian Vettel in Britain and Germany. The other bad thing is a low launch torque which gives you not much chance to fix your bad launch. You can only wait until you have accelerated enough to drop the full torque lever. One of these things probably also happened to Webber in Belgium. Barrichello also had problems with launch torque in the Brawn last year (Turkey).

[Pup]

Actually, I had quickly read flynfrog's post and thought he was saying that the driver gradually let out the clutch paddles like you would with a pedal. I was, um, 'politely' questioning that.

[Richard]

The clutch levers on the steering wheel do nothing but activate the preset launch torque and full torque later.

That's strange because the rules say the clutch levers have to range from full torque to zero torque? They are also explicit that preset torque is not allowed.

*puzzled*

[WhiteBlue]

That's strange because the rules say the clutch levers have to range from full torque to zero torque? They are also explicit that preset torque is not allowed.*puzzled*

Can you quote the relevant passages of the regulation you refer to?

[youtube]http://www.youtube.com/watch?v=5Rsz4yW53aM[/youtube]

This is the information I have about the working of the clutch. I do not know actually if they do it with a binary switch or by a proportional actuator on the lever. I think it would be done most efficiently by a binary switch.

[Richard]

I quoted the relevant rules on the previous page.

Zero to full engagement - 9.2.3
No presets - 9.2.2

As Pup suggested - Perhaps they have two clutches in parallel. The first one transmits just enough power for initial traction when fully engaged (cl 9.2.3), the second transmits the remainder.

I think the interconnected system outlined by Flynfrog would be illegal under cl 9.2.2 and 9.2.3

[WhiteBlue]

9.2.1 If multiple clutch operating devices are used, they must all have the same mechanical travel characteristics and be mapped identically.
9.2.2 Designs which allow specific points along the travel range of the clutch operating device to be identified by the driver or assist him to hold a position are not permitted.
9.2.3 The minimum and maximum travel positions of the clutch operating device must correspond to the clutch fully engaged normal rest position and fully disengaged (incapable of transmitting any useable torque) positions respectively.

I do not know how teams reconcile 9.2.2 and 9.2.3 with the practice that Coulthard describes. They definitely do not have two clutches which is prohibited by 9.2.1. The two levers work on one and the same clutch mechanism and the second lever activates the launch clutch torque. richard_leeds is probably right that they have to hold the semi set clutch lever at a position to activate the launch clutch torque. Good call of the regulations by him!!

[Richard]

WB - They can use multiple clutches, note the plural in 9.2:

9.2 Clutch control :
The following applies only to the main drive train clutch or clutches, any clutch used exclusively as part of a KERS is exempt.

Its the only way I can see that allows them to dump two paddles.

[autogyro]

Not only illegal but less efficient.
Two clutches means either two layshafts ot two mainshafts one inside the other.
Both configurations are used in road and performance cars and work well.
However there is more torque loss than from a conventional single layshaft/clutch gearbox as used in F1.

[autogyro]

WB - They can use multiple clutches, note the plural in 9.2:

9.2 Clutch control :
The following applies only to the main drive train clutch or clutches, any clutch used exclusively as part of a KERS is exempt.

Its the only way I can see that allows them to dump two paddles.

This regulation would come into its own only 'if' the KERS was a part of the gearbox.
At present the KERS systems available are seperate, so the regulation exemption cannot apply to direct apply cluches or internal clutches working solely on the conventional power train.

[WhiteBlue]

WB - They can use multiple clutches, note the plural in 9.2:

9.2 Clutch control :
The following applies only to the main drive train clutch or clutches, any clutch used exclusively as part of a KERS is exempt.

Its the only way I can see that allows them to dump two paddles.

But 9.2.1 says that multiple clutch devices must have identical travel characteristics and identical mapping. So a second clutch assembly has no advantage. Besides commentators have told it several times that they use two levers on one clutch.

I would think that there is a programmable logic which tells the clutch the priority of the two clutch levers. I would do it by making always the most open values applicable.

[RH1300S]

The way I read DC's comments are as follows:

2x identical clutch levers - which would seem to be able to work simultaneously.

The driver uses his own judgement to hold one lever at a certain position (perhaps they have ways of judging this? could even be as simple as a fingers width behind the lever?).

Then releasing one lever leaves the second controlling the bite point. Which I assume the driver could instantaneously adjust in or out in the same way a normal clutch works.

Simple - and fits the rules.

Also as the clutch levers are identical in operation the driver could choose to swap hands and it still works the same way.

[autogyro]

The way I read DC's comments are as follows:

2x identical clutch levers - which would seem to be able to work simultaneously.

The driver uses his own judgement to hold one lever at a certain position (perhaps they have ways of judging this? could even be as simple as a fingers width behind the lever?).

Then releasing one lever leaves the second controlling the bite point. Which I assume the driver could instantaneously adjust in or out in the same way a normal clutch works.

Simple - and fits the rules.

But really just a compromise to allow a small diameter clutch with no flywheel to be controlled at all, when it would be impossible to do it without help from the computer.

[Richard]

But really just a compromise to allow a small diameter clutch with no flywheel to be controlled at all, when it would be impossible to do it without help from the computer.

I don't get that, what has a computer got to do with it? This is about a driver pulling on a paddle and an electronic controller operating the clutch according to the paddle position. You could achieve the same with cables.

[autogyro]

But really just a compromise to allow a small diameter clutch with no flywheel to be controlled at all, when it would be impossible to do it without help from the computer.

I don't get that, what has a computer go to do with it? This is about a driver pulling on a paddle and an electronic controller operating the clutch according to the paddle position. You could achieve the same with cables.

You could but unless it is done with the driver controling the clutch biting point (correct term) without the assistance of a pre set electronic system, it is in fact an 'automatic' system and should be banned.
Hope that meets with approval from the motor heads.