1997 marked the debut of the new FIA-approved World Rally Car class, it's use restricted to WRC events. But Mitsubishi Motors decided to continue with the Lancer Evolution in Group A, this class being much closer structurally to the production model. Launched in January 1998, Evolution 5was given a wider track to stay competitive against the World Rally Car class.
Although still producing 276bhp, the use of turbocharger (TD05HR-16G6-10.5T) nozzles with larger surface areas increased maximum torque to 274lbs/ft at 3,000rpm.
Evolution 5 measured in with a front track of 1510mm and rear track of 1505mm, while overall width was extended to the 1770mm limit permitted by the regulations using aluminium front fenders and macho rear over-fenders. Evolution 5 ran on new17-inch wheels shod with wide 225/45R17 rubber as standard. At the front, aerodynamic and cooling performance was enhanced with a canard-spoiler under the front bumper and larger grille openings to match the uprated radiator. The outlets in the aluminium engine hood were enlarged and reshaped for better heat extraction. While retaining the delta-shaped wicker, the rear deck spoiler was optimised for position and used an aluminium wing with adjustable attack angle.
Evolution 5 Extras
The suspension was optimised for the wider track. The front gained a camber adjuster and inverted struts. While overall stiffness was beefed up, wheel stroke lengthened and steering gearbox relocated, weight was reduced and geometry optimised. At the rear, improvements were made to all inner and outer pivot points, geometry was optimised, weight reduced and stiffness substantially increased. The rear roll centre was also optimised to realise more responsive behaviour and better tire-road contact. With the larger wheels and tires, braking was upgraded with Brembo 17-inch ventilated disc with 4-pot calipers at the front and 16- inch ventilated disc with 2-pot calipers at the rear.
Options included mud flaps, boost gauge, front and rear strut bars and an uprated suspension kit.
Evolution 6 arrived in January 1999 with some fine tuning to its aerodynamics after changes in the 1999 WRC regulations restricted the size of aero attachments and a dramatic improvement in cooling performance.
Cooling was improved by off setting the license plate and using smaller fog lamps to enable the effective area of the bumper openings to be enlarged, while new ventilator and airflow ducts in the bumper enhanced the performance of the oil cooler. Drag was reduced with the use of hemi-spherical fog lamp covers, while the introduction of a twin-wing rear deck spoiler design made up for the reduction in downforce resulting from its smaller size. Evolution 6’s engine generated the same maxima as its predecessor, but detail modifications improved reliability and response.
A titanium-alloy turbocharger turbine - a world first - on the RS model improved throttle response, while the addition of a cooling channel in the pistons improved reliability. Increasing coolant circulation by changing the layout of the coolant passages reduced cavitation. Improvements to the oil pan baffles and the use of an uprated oil cooler stabilised oil temperature at high engine loads.
Evolution 6 Extras
Detail changes to the suspension included: greater stiffness resulting from the use of forged front knuckles, and a lowering of the roll centre by transferring the ball joint from the forged aluminium lower control arm to the knuckle, both resulting in better tire-road contact. At the rear, the use of forged aluminium for the lower control arms, trailing arms and toe control arms reduced the un sprung weight of the vehicle. A longer rebound stroke also improved tire-road contact. Body stiffness was increased with an additional 130 spot welds, the use of structural adhesive and the use of thicker gauge sheet metal in some panels.
These detail changes enabled Evolution 6 to achieve new peaks interms of response, grip and handling stability. Another trim level was introduced, RS2, combining the RS-only hardware specification with a modicum of the GSR's niceties. Dealer options included PIAA fog lights, mud flaps and uprated suspension kit.