Lotus 2004 ELISE Service Notes page 470

Lotus Service Notes
Variable Traction & Launch Control (if fitted)
Cars equipped with the optional variable traction and lauch control, have a rotary control knob mounted
above the LTC 'off' button on the switch panel.
Variable Traction Control
Each time the ignition is turned on, normal full LTC is activated. To enable variable traction control, turn
on the ignition and hold the LTC 'off' button pressed for 2 seconds. Do not touch the throttle pedal. Check that
the tell tale in the switch button is lit. Start the engine. Note that if the ignition is switched off (e.g. prior to a
second start attempt), the above procedure must be repeated in sequence.
With the switch button tell tale lit and the engine running, the rotary knob may then be used to select the
degree of traction control desired:
• For maximum traction control (0% slip) turn the knob fully counterclockwise.
• To reduce traction control (to allow up to 12% slip), turn the knob progressively clockwise.
• Fully clockwise, traction control is disabled, as indicated by the lighting of the instrument panel tell tale.
Variable Launch Control
This feature allows the engine rpm to be limited during a competition start in order to balance engine power
against available grip and provide a controlled degree of wheelspin for the first moment of acceleration, until
superseded by the traction control system at around 6 mph.
To enable this feature, turn on the ignition and hold the LTC 'off' button pressed for 2 seconds. Check that
the tell tale in the switch button is lit. Then;
• With ignition on, engine stopped, fully depress the throttle pedal for 5 seconds.
• Tacho will now show launch rpm. Turn the rotary knob as necessary to select any desired launch rpm
between 2000 and 8000.
• Release throttle and start engine.
• Turn the rotary knob to select the desired level of traction control (see above), noting that the launch control
setting will not be affected.
• Engage first gear, apply full throttle (ECU limits engine speed to selected launch rpm), and rapidly 'drop'
clutch.
• Maintain full throttle throughout the transition from launch to traction control (at around 6 mph) until the
first gear change is required.
• To disable launch control when variable traction control is still required, reset launch rpm to 8,000.
NOTE
• Do not attempt to slip the clutch during this process, as overheating or damage to the clutch mechanism
may occur. An instant clutch engagement is required to 'break' rear tyre traction and initiate wheelspin.
• Do not attempt LC starts in any gear other than first.
• Do not hold the engine at or near maximum rpm for more than a few seconds.
• Under no circumstances should this track feature be employed on the public road.
• Use of Launch Control is an ultimate technique designed to produce the fastest possible race start.
Always allow the clutch to cool and recover before repeating a launch controlled start. The extreme
loads associated with such starts will result in reduced transmission component life cycles.
• At the next key-on, the system will default to full LTC and Launch Control off. Turning on the ignition and
holding the LTC 'off' button pressed for 2 seconds will restore the previous traction and launch settings.
Adjustment Tips
Note that the optimum settings for variable traction and launch control will differ for each set of track sur-
face, tyre and ambient conditions. A suggested adjustment logic follows:
• Set the traction control to a mid position.
• Start with a low launch rpm e.g. 4,000 rpm.
• Trial launch and assess initial wheelspin control and transition into traction control.
• If launch control is set too low, the engine may 'bog down' and fall out of the power band. If set too high,
too much initial wheelspin may result, with poor step off from the line.
• Similar logic applies to traction control adjustment when this system takes over above about 6 mph.
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