Lotus 2004 Eleven Service Notes page 521

Lotus Service Notes
2-ELEVEN.F - TRANSMISSION
Clutch
The 2-Eleven is fitted with an uprated clutch cover assembly rated for a maximum torque of 362 Nm, and
which enjoys a mass reduction of 0.6 Kg over the regular cover. Also fitted is an uprated friction plate which
uses 4 steel compression springs in the cush drive hub, in place of the regular item's 4 rubber blocks.
Differential
The 2-Eleven is fitted as standard with an 'open' bevel gear differential, supplemented by switchable Lotus
Traction Control (LTC), with an option package of variable LTC with Launch Control. For full details of these
electronic systems, refer to Section 2-Eleven.M
Two types of optional Limited Slip Differential (LSD) are also available.
Torsen Type: A Torsen (TORque SENsing) gear type LSD limits the speed differential between the two rear
wheels by mechanically distributing the applied torque in accordance with the available grip at each tyre. The
LSD uses worm wheels to interconnect the two output shafts and uses the poor torque reversal efficiency
of this type of gearing to ensure that both wheels are always supplied with driving torque. This feature can
enhance vehicle performance in some competition events, and help maintain mobility in some types of soft
ground condition.
Apart from the taper roller bearings supporting the differential in the transmission case, the LSD is not
serviceable. For details of bearing preload adjustment, refer to Service Notes sub-section FJ.6. There is no
special oil requirement for the Torsen LSD. All factory supplied transmission assemblies originally built with
Torsen LSD are identified on the bar code label applied to the top surface of the transmission case; The 3rd
character of the 7 digit code is 'O' for open differential, and 'L' for limited slip.
Plate Type: A competition type friction plate LSD made by TRD is available in both '2 way' and '1.5 way' variants.
This type of LSD uses a pack of friction clutch plates between each differential output gear and the differential
carrier. The load applied to the clutch pack is proportional to the input torque via a cam and ramp angle design
incorportated between the 4-pinion spider (driven by the crownwheel) and the two clutch pack assemblies. The
'stiffness' of the LSD operation is dependent on the ramp angle which may be specified on ordering. A '2 way'
LSD uses the same ramp angles for drive and overrun to provide similar slip control in both conditions. A '1.5
way' LSD uses different ramp angles for drive and overrun to reduce the clutch pack load on braking. There is
no special oil requirement for the plate type LSD, but to maintain design performance, inspection and cleaning
of the plates should be carried out every 15,000 miles (25,000 km) by a competent agent.
2-ELEVEN.G - WHEELS & TYRES
Optional on the 2-Eleven are 240R type lightweight forged alloy 5-spoke roadwheels, which at 7x16 and
8x17, are ½ inch wider, front and rear, than the standard Exige wheels, but retain the standard insets of + 31.3 mm
and + 38.0 mm. The wheels are finished in either Satin Black or High Power Silver, with 'Lotus Sport' moulded
into one of the spokes of each wheel. The Lotus specific, regular Exige Yokohama A048 tyres, identified by
'LTS', are fitted as standard. Each wheel is retained by four standard Elise/Exige spline head 60 degree taper
seat bolts, for which a splined adaptor tool is stowed in the vertical tube of one of the roll-over bar backstays.
No security coded wheel bolts are used.
Note that these forged alloy wheels incorporate a steel centralising sleeve to locate onto the hub spigot,
and is normally retained in the wheel. A smear of copper grease on the spigot will help prevent corrosion be-
tween the hub and sleeve causing the insert to become separated from the wheel.
2-ELEVEN.J - BRAKES
The anti-lock braking system is uprated in the following respects:
- Motorsport brake pads (Pagid RS14) are fitted front and rear together with cross-drilled brake discs;
- Steel braided brake hoses fitted all round;
- Optional Castrol 'SRF' synthetic racing brake fluid. Over 500°F boiling point. Dot 4.
- Brake callipers painted yellow.
2-Eleven
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