Guide: Lotus Elise S1 Sport 135
Background
When Lotus unveiled the Elise at the Frankfurt Motor Show in September 1995, it gave the firm a much-needed shove in the right direction.
Although the long-running Esprit and outgoing front-wheel drive M100 Elan were both very fine cars, neither was truly in the spirit of Colin Chapman’s original ethos.
The back-to-basics Elise was exactly what the company needed. It received universal praise from road testers and customers alike – the only problem was keeping up with demand once production started in June 1996.
Such was the capability of the Elise platform that it was not long before after-market tuning companies began to offer performance upgrades; with a chassis and engine capable of handling considerably more power than the standard 118bhp engine, lots of customers began to upgrade their Elises.
In 1998, Lotus themselves got in on the act.
March of that year saw the hardcore track-focused Sport 190 launched. However, with its radical, uncompromising specification and 40% price premium over a standard Elise, the Sport 190 was never likely to be a big seller.
During the summer of 1998, Lotus announced that existing that Elise owners could order an after-market Stage 2 tuning kit from their local dealer.
The Stage 2 kit comprised a ported and polished cylinder head with a VVC plenum and a sports exhaust with de-cat pipe.
Peak power officially went from 118bhp at 5500rpm to 135bhp at 6200rpm.
The torque rating was now 129lb-ft at 4250rpm compared to 122lb-ft at 3000rpm for the standard car.
In November 1998, Lotus decided to offer a factory-built Sport 135 with an array of additional performance enhancements beyond the hot motor. The suspension, brakes, gearbox, exterior and interior all came in for attention. Unsurprisingly, the limited run of 50 cars initially announced sold out on the first day of availability.
Chassis
Each Sport 135 was built around the standard Elise’s epoxy-bonded aluminium spaceframe with integral steel roll-over hoop. At just 68kg, the finished chassis was extremely light, but also offered phenomenal strength and torsional rigidity.
The wheelbase was a compact 2300mm.
Suspension was via double wishbones with co-axial coil sprung inverted monotube dampers and Lotus-patented extruded aluminium uprights.
The Sport 135 was uprated with re-valved Koni dampers and shorter, stiffer springs that gave a lower ride height. A beefier front anti-roll bar was also installed.
Cast-iron brake discs were now cross-drilled as well as ventilated. They retained the 282mm diameter of the standard Elise in addition to AP Racing calipers up front and Brembo items out back.
Wheels and tyres were unchanged. The Sport 135 ran AWI five twin-spoke alloy wheels of 5.5 × 15-inches at the front and 7 × 16-inches at the rear all shod with Pirelli P Zero tyres.
A standard 40-litre fuel tank was located under the rear of the cockpit floor.
Engine / Gearbox
At the heart of this latest variant was Rover K-series engine with ported and polished Lotus Sport 135-branded cylinder head. Other new equipment included the intake manifold and plenum from Rover’s Variable Valve Control engine (VVC) plus a sports exhaust with de-cat pipe.
The K-series Rover engine was an all-alloy dual overhead camshaft 1.8-litre inline four with wet-sump lubrication and four valves per cylinder. It displaced 1796cc thanks to a bore and stroke of 80mm and 89.3mm respectively.
Lotus mounted the engine transversely on a steel subframe bolted to the back of the spaceframe.
Engine management was courtesy of a MEMS 1.9 system. Electronic ignition was supplied by Motorola.
A 10.5:1 compression ratio was retained.
The Sport 135 was officially quoted with 135bhp at 6200rpm but 145bhp was considered to be a more realistic output.
Its torque rating was 129lb-ft at 4250rpm.
For comparison, the standard Elise produced 118bhp at 5500rpm and 122lb-ft at 3000rpm.
Another special Sport 135 feature was the close-ratio five-speed gearbox.
Bodywork
All 50 cars produced were painted a special colour called Quicksilver (a blue-tinted shade of silver) with a matching rollover bar and dark blue canvas soft top.
Covered headlights and front spot lights were fitted as standard along with Sport 135 graphics ahead of each rear wheel.
As usual, body panels were fashioned exclusively from glassfibre composite; the single-piece front and rear body sections were detachable for easy access to the running gear.
The Julian Thompson-designed Elise had tapped into the mid nineties trend for retro lines; its curvaceous body incorporated fixed headlights mounted high up on the front fenders, a panoramic domed windscreen and a rounded tail with four circular lights and two arced mesh cooling vents either side of the twin-pipe centrally exiting exhaust.
Additional downforce was created by the front winglets, a full-width rear spoiler and an underbody diffuser.
Intake ducts and air vents were scattered all around; down each flank were large scoops while at the front of the car, fresh air was fed through a wide oval intake and then extracted via two huge curved vents further up the nose.
Interior
Inside, Lotus fitted a two-tone red and black alcantara-trimmed steering wheel and matching Corbeau-branded seats.
The rest of the cockpit specification was standard Elise.
This meant an only partially upholstered cabin (sills, door panels and seats) while the metal upper dash and transmission tunnel were given a dark grey textured finish. The rest of the surfaces were left in bare aluminium.
The curved two-gauge instrument binnacle housed analogue read outs for road and engine speed. All other vital statistics were accessed via the Stack digital readout located at the base of the two main dials.
Single-piece bucket seats could be adjusted fore / aft only. To give the driver the clearest possible vision, the driver’s seat was positioned closer to the centre of the car than the passenger’s (which was fixed in the rearmost position).
Wind-down windows and floor mats were standard.
Options
Optional extras included a body-coloured hard top, a radio fitting kit and an alarm / immobiliser.
Weight / Performance
Weight was unchanged at 755kg.
Top speed went from 126mph to 130mph.
However, it was acceleration where the Sport 135 really excelled; thanks to its extra power, torque and that close-ratio gearbox, the new model was punchier throughout the rev range and was half-a-second quicker to 62mph (5.3 seconds as opposed to 5.8).
Production
All 50 examples of the Sport 135 were produced in December 1998.
Chassis numbers ranged from 5401-5450.
Sport 135 99
As demand for the Sport 135 had far-exceeded supply, Lotus decided to create a second batch of 35 cars during January and February of 1999.
This final run came with several new pieces of equipment to include the six-spoke OZ Racing wheels from the recently launched Elise 111S, a stone guard protector for the rear fenders, a black fuel-filler cap, a matt finish alloy gear knob, Elise-branded window winders and Sport 135 99 decals down each flank.
Additionally, customers could now specify whatever colour they wanted from the Elise range.
Chassis numbers ranged from 6001 to 6035.
Text copyright: Supercar Nostalgia
Photo copyright: Lotus - https://www.lotuscars.com
