[TRD-Power]

Front and Rear Differentials
In the interest of delivering the ultimate traction and road holding, the Lancer Evolution performance sedan is equipped with a pair of rugged bevel gear mechanical differentials that directing driveline power to each of the wheels, and help the vehicle maintain traction on all surfaces. The front differential is an open-type bevel gear unit, while the Lancer Evolution’s rear differential is a reliable, #4.2-sized mechanical, plate-style, limited slip differential unit. The driveline and differential arrangement has proven itself successful in competition beneath the race-oriented Lancer Evolution RS model that had served as the basis for Lancer Evolution race car preparation in the past.

Illustration of mechanical limited slip rear differential that uses metal friction discs and pressure rings load the center bevel gear arrangement and control traction and limit wheel slippage.

Exploded view of a mechanical, plate-style limited slip differential. The design of friction plates allow little in the way of wheel slippage and help the center bevel gearset provide optimal torque transfer for acceleration and high speed cornering. Such LSD units have proven extremely reliable in competition.

Propeller Shaft and Drive Shafts
The Lancer Evolution sedan is equipped with a rugged three-piece, four-joint propeller shaft that transfers engine power from the front to the rear differentials. This propeller shaft uses hardened shaft sleeves, reinforced yokes and upgraded joints to make the assembly more reliable in competition, and performance driving. The transmission of power from the differentials to the wheels hubs are handled by driveshafts constructing using larger diameter lengths of high-strength, heat treated steel. The front shafts employ heavier duty constant velocity joints, and surface treated spline ends that are supported using large diameter bearings designed to handle the additional output of the Lancer Evolution motors in competition.

Lancer Evolution driveshaft transmits power to the wheels from the differential and are constructed using larger diameter, surface treated shafts and heavier duty constant velocity joints. Larger diameter bearings help support all four of these driveshafts.

Suspension

A high-performance vehicle’s increased power levels necessitate a more capable suspension and braking system that has been suitably reinforced to fully exploit and maximize the engine’s capability. The 2003 Mitsubishi Lancer Evolution’s high-performance compact sedan relies on a highly modified evolutionary design of the Lancer sedan‘s competent suspension arrangement to satisfy the demands of world rally competition and high-performance driving. The vehicle’s widened track (1,515 mm) and use of low-profile, soft compound tires improve handling stability, initial response and help raise the Lancer Evolution’s cornering limits. The basic Lancer suspension design is reinforced in several locations to improve the performance of this competition-oriented vehicle’s undercarriage. For instance, a stiff, reinforcing bar spans the distance across the front suspension crossmember and helps increase the front suspension mounting point stiffness, as well as reduces the vehicle roll in high-G turns, and improves steering feel and response. The competition-proven combination of front Macpherson struts and rear multi-link suspension design, is modified for increased rigidity, reduced mass and an optimized roll center that endows the Lancer Evolution with excellent straight line stability as well as superior turning capability, road holding, and responsiveness.

The Lancer Evolution replaces the Lancer sedan’s stamped-steel suspension components with lightweight aluminum forgings to improve suspension performance and durability.

Front Suspension
The function and capability of Lancer’s basic front Macpherson strut suspension design has been enhanced with unique-for-Lancer Evolution lightweight components and reinforcing measures that are the result of careful study of the suspension movement, their mounting points, and flexural tendencies of components during competition. The Lancer Evolution sedan relies on durable, large diameter, gas-charged, inverted struts, extensive reinforcement of the unibody hard points related to the suspension component mounting, and the use of forged aluminum construction for critically stressed suspension components. The oversized, off-road capable, inverted struts help ensure smoother shock absorber action during high speed corners as well as allowing for the specification of a larger capacity strut insert that can better withstand the punishment of spirited driving.
A lightweight forged aluminum lower control arm helps reduce the load on the coil springs and strut; the reduced mass of this large aluminum component allows the suspension to react much quicker to surface changes. The Lancer Evolution front suspension uses a rugged 24 mm stabilizer bar equipped with pillow-ball bushing end-links that offer better movement and improve the stabilizer’s efficiency, function and stability. A robust, supportive, steel, unibody crossmember connects the left and right lower control arm mounts and helps increase lateral rigidity with additional stiffness to improve steering feel and response. This component is reinforced by a strong, inflexible bar that interconnects the lower control arm mounting points to provide additional support, strength, and help better maintain suspension mounting point geometry in the face of high torsional and flexural loads experienced during high speed cornering.

Forged aluminum used in the construction of the lower control arm and the front knuckle arm add strength and unsprung reduced weight. The function of these lightweight pieces is enhanced by using pillow-ball mounts and ball joints to reduce the friction of their movement. In addition, larger bearings are integrated into the hub to help improve reliability and durability under rigorous conditions. The redesigned strut insulator helps reduce vibrations transmitted to the unibody that could interfere with steering feel, and the top of the strut mount relies on a more stable metal bearing to help control movement.
The Lancer Evolution utilizes a quick-ratio (13:1) power assisted rack-and-pinion steering system to produce faster steering response and improved maneuverability. The steering gearbox mounting position has been lowered to achieve greater linearity in suspension toe changes, and offer greater turning stability. The Lancer Evolution’s alignment settings are specified to provide superior control, stability and deliver excellent response from the chassis, fully exploiting the vehicle’s wider track and optimized roll center to improve cornering.

Suspension design and materials changes from Lancer sedan to Lancer Evolution specification.