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Transmission system

Published with permission from the Federation Internationale de l' Automobile.

ARTICLE 9: TRANSMISSION SYSTEM
9.1
Transmission types :
No transmission system may permit more than two wheels to be driven.
9.2Clutch control :
The following applies only to the main drivetrain clutch or clutches, any clutch used exclusively as part of an ERS is exempt.
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.
9.2.4 Designs or systems which in addition to typical inherent hydraulic and mechanical properties are designed to, or have the effect of, adjusting or otherwise influencing the amount, or rate, of engagement being demanded by the FIA ECU, are not permitted.
9.2.5 The amount by which the clutch is engaged must be controlled solely and directly by the driver with the exception of :
a) Stall prevention.
b) Gearshifts.
c) Bite point finder where brake pressure, wheel speed and driver clutch demand safeguards are used.
d) De-clutch protections.
e) Drivetrain protection on the track outside of any start lockout period or immediately following stall prevention activation only.
f) Test signals enabled only when the car is connected to the garage system.
The relationship between the clutch operating device in the cockpit and the amount of clutch engagement may be non-linear but must remain fixed.
9.2.6 When the clutch operating device is released from its maximum travel position it must return to its resting position within 50ms.
The maximum delay allowed, computed from the respective positions as recorded by the ADR or ECU, between the clutch driver control input signal and the corresponding output demand being achieved is 50ms.
9.2.7 Any device or system which notifies the driver of the amount of clutch slip or engagement is not permitted.
9.3 Traction control :
No car may be equipped with a system or device which is capable of preventing the driven wheels from spinning under power or of compensating for excessive torque demand by the driver.
Any device or system which notifies the driver of the onset of wheel spin is not permitted.
9.4Clutch disengagement :
All cars must be fitted with a means of disengaging the clutch for a minimum of fifteen minutes in the event of the car coming to rest with the engine stopped. This system must be in working order throughout the Event even if the main hydraulic, pneumatic or electrical systems on the car have failed. This system must also disconnect any ERS system fitted to the car.
In order that the driver or a marshal may activate the system in less than five seconds, the switch or button which operates it must :
a) Face upwards and be recessed into the top of the survival cell no more than 150mm from the car centre line.
b) Be designed in order that a marshal is unable to accidentally re-engage the clutch.
c) Be less than 150mm from the front of the cockpit opening.
d) Be marked with a letter "N" in red at least 40mm tall, with a line thickness of at least 4mm, inside a white circle of at least 50mm diameter with a red edge with a line thickness of at least 2mm.
9.5 Gearboxes :
9.5.1
A gearbox is defined as all the parts in the drive line which transfer torque from the power unit output shaft, as described in Article 5.3.2, to the drive shafts (the drive shafts being defined as those components which transfer drive torque from the sprung mass to the un-sprung mass). It includes all components whose primary purpose is for the transmission of power or mechanical selection of gears, bearings associated with these components and the casing in which they are housed.
9.5.2 In this context the following parts are not considered part of the gearbox and may be changed without incurring a penalty under the F1 Sporting Regulations. If changing any of these parts involves breaking an FIA applied seal this may be done but must be carried out under FIA supervision:
a) The clutch assembly and the power unit output shaft, provided this is located prior to any mechanical speed reduction from the engine.
b) The clutch actuator and clutch release bearing(s).
c) Inboard driveshaft joints and seals but not their housing if that housing is integral with the gearbox output shaft and therefore part of the sprung mass.
d) The hydraulic system prior to the point at which it produces direct mechanical movement of the gear selection mechanism by means of hydraulic actuator(s).
e) Oil, oil pumps, oil filters, oil seals, oil coolers and any associated hoses or pipes.
f) Electrical sensors, actuators, servo valves and wiring.
g) Any parts associated with the suspension or functioning of the sprung suspension that are attached to the gearbox casing.
h) The rear impact structure provided it can be separated from any gearbox casing.
i) Any other component mounted to the casing whose primary purpose is unconnected with the transmission of power or selection of gears.
9.6 Gear ratios :
9.6.1
The number of forward gear ratios must be 8.
9.6.2 Each competitor must nominate the forward gear ratios (calculated from engine crankshaft to drive shafts) to be employed within their gearbox. These nominations must be declared to the FIA technical delegate at or before the first Event of the Championship. For 2014 only a competitor may re-nominate these ratios once within the Championship season, in which case the original nomination becomes immediately void. Ratio re-nominations must be declared as a set.
9.6.3 No forward gear ratio pair may be :
a) Less than 12mm wide when measured across the gear tooth at the root diameter or any point 1mm above or below the root diameter. Above this area each side of the gear teeth may be chamfered by a maximum of 10¢ª. In addition, a chamfer or radius not exceeding 2.0mm may be applied to the sides and the tip of the teeth.
b) Less than 85mm between centres.
c) Less than 600g in weight (excluding any integral shaft or collar). If an integral shaft or collar is to be excluded the mass of this may be shown by calculation assuming the gear to be 12mm wide and the shaft geometry to be the same as that where slide on gears are used.
9.6.4 Gear ratios must be made from steel.
9.6.5 Continuously variable transmission systems are not permitted to transmit the power of the power unit defined in Article 5.1.
9.7 Reverse gear :
All cars must be able to be driven in reverse by the driver at any time during the Event.
9.8 Gear changing :
9.8.1
Automatic gear changes are considered a driver aid and are therefore not permitted.
For the purposes of gear changing, the clutch and power unit torque need not be under the control of the driver.
9.8.2 Gear changing is restricted during the following periods :
One gear change is permitted after the race has started and before the car speed has reached 80km/h, provided every gear fitted to the car is capable of achieving at least 80km/h at 15,000rpm.
9.8.3 The minimum possible gear the driver is able to select must remain fixed whilst the car is moving.
Each individual gear change must be separately initiated by the driver and, within the mechanical constraints of the gearbox; the requested gear must be engaged immediately unless over-rev protection is used to reject the gear shift request. Once a gear change request has been accepted no further requests may be accepted until the first gear change has been completed.
Multiple gear changes may only be made under Article 5.22 or when a shift to gearbox neutral is made following a request from the driver.
If an over-rev protection strategy is used this may only prevent engagement of the target gear, it must not induce a delay greater than 50ms. If a gear change is refused in this way, engagement may only follow a new and separate request made by the driver.
Any de-bounce time used to condition driver gear change requests must be fixed.
9.8.4 The maximum permitted duration for down changes and up changes is 300ms and 200ms respectively. The maximum permitted delay for the latter is 80ms from the time of the driver request to the original gear being disengaged.
The duration of a gear change is defined as the time from the request being made to the point at which all gear change processes are terminated. If for any reason the gear change cannot be completed in that time the car must be left in neutral or the original gear.
9.8.5 Distance channel or track position is not considered an acceptable input to gearbox control.
9.9 Torque transfer systems :
9.9.1
Any system or device the design of which is capable of transferring or diverting torque from a slower to a faster rotating wheel is not permitted.
9.9.2 Any device which is capable of transferring torque between the principal axes of rotation of the two front wheels is prohibited.