[TRD-Power]

More Metal-More Welds
Engineers relied on additional strategically placed welds, thicker metal materials and several carefully placed steel reinforcing members to improve the torsional strength and rigidity of the Lancer Evolution sedan. The design and positioning of these steel reinforcing supports are the result of lessons learned from extensive computer modeling, and the real-world application of such chassis strengthening measures during the competition careers of previous generation Lancer Evolution sedans. These structural measures help the Lancer Evolution’s unibody double the torsional rigidity of the base Lancer sedan as well as improve on the platform’s flexural rigidity by 1.6 times. The Lancer Evolution’s competition-proven unibody structure is up to the challenge presented by the repeated punishment the vehicle is expected to encounter on the rally circuit, but the unibody’s enhanced structural soundness helps the vehicle’s performance and response under a variety of conditions.


Steel Strength Reinforcement

No.
Component Detail

Description1, 2
Front suspension mount
Four additional spot welds on each side of the panel increases the rigidity of the body panel connections that comprise the suspension mount. Ring-shaped reinforcement metal was added to the top of the strut mount surface to help strengthen and stabilize the suspension mounting. The strut tower panel itself is constructed entirely from thicker gauge metal for improved strength.
3
Strut brace mount
A reinforcing member added within the top of the vehicle’s cowl, located at the center of the strut tower bar connection helps increase the strength and stability of the strut tower bar’s cowl connection.
4
Front deck crossmember mount
The front deck crossmember, which had previously been added to the driver’s side, is extended through to the passenger side of the dash panel bulkhead, and helps reduce the effects of flexural or twisting forces acting on the unibody.
5, 6
Rear suspension mounting point
Five additional welds are added to the reinforcement in addition to thicker ring-shaped sheetmetal that contacts the top of the rear strut’s spring perch, and help further stabilize rear suspension movement.
7
Additional rear suspension support
A reinforcing member added to the top of the rear wheel housing helps increase the Lancer Evolution’s body rigidity and helps add support to an area that offers secondary reinforcement to the suspension mounting area.
8
Wheel housing support
Additional material added to the side of the rear wheel housing helps increase the rigidity of this area of the body, and provides additional support to the panels that support the suspension.
9
Bottom of center pillar
A large reinforcing member welded to the outer panel side of the bottom of the center pillar helps strengthens the connections between the upper and lower body assemblies.
10
Lower center pillar
A large reinforcing member has been added to the inside of the center pillar at the bottom of the structure where the pillar connects with the lower portion of the vehicle.
11
Rear floor panel
The rear floor panel was completely redesigned to accommodate the increased size of the fuel tank, and its construction includes the use of thicker metal panel material to help reduce flex.

Several areas of the unibody that are critical to the Lancer Evolution chassis’ performance in competition have also been reinforced or modified to help improve the vehicle’s competitiveness in rally competition while enhancing the function and performance of the vehicle’s suspension. For instance, both the Lancer sedan and the Lancer Evolution variants utilize MASH seam welded construction, a process that relies on multiple thin sheets of welded steel instead of one larger, heavier gauge piece, for the front subframe rails, and the B-pillars to help these vital stress-bearing unibody structures achieve optimal strength without a major weight penalty.
Front-end Vehicle Detail
With engineers focused on designing a vehicle that maintains the most stable and consistent suspension geometry under all conditions, the Lancer sedan utilizes a pipe and thru-hole construction for its suspension mount design to help increase the rigidity of the front suspension mount. This same effective design is carried over to the Lancer Evolution, which can rely on this suspension mounting design to withstand the demands of competition.

The Lancer Evolution sedan includes the placement of an additional welded steel member that acts as a stress-dispersing gusset connecting the top of the inner fenderwell panel member of the front subframe to the bottom of the A-pillar. This thoughtfully positioned, welded piece of metal helps control both lateral and vertical forces acting against the subframe and the dash bulkhead as the vehicle travels over the most unforgiving terrain.

Mitsubishi engineers sought to offset the weight of the numerous steel reinforcing supports by employing weight-conscious construction for some non-load bearing structures such as the aluminum front fenders and the vented aluminum hood. The placement of these lightweight panels at the vehicle’s front half, help relieve front end weight bias, and reduce the vehicle’s center of gravity to help improve the vehicle handling balance and response.

Weight reducing construction as well as use of lightweight aluminum for other non-load bearing members, including the fender and hood help offset the additional weight of many of the vehicle’s steel structural reinforcements.

Rear Vehicle Reinforcement
In the interest of improving rear suspension performance, structural details at the rear of the unibody are addressed to improve rigidity, reduce flex, and allow the modified suspension to perform under the stress of competition. Just as with the front half of the vehicle, the placement of additional welds, reinforcing members, and suspension mounting design is the result of the lessons learned by campaigning previous models of the vehicle in high-level competition.

No.
Component Detail

Description

1
C-pillar
A reinforcing support under the outer skin of the C-pillar attaches the pillar to the reinforced structure above the rear wheel well opening.
2
Rear trunk floor member
A welded member spans the center of the trunk floor and helps form a strong rear support along with the v-shaped support pillar.
3
Trailing arm mount
A reinforced trailing arm mount helps ensure the durability of this crucial, stabilizing suspension mount in all conditions.
4
Upper control arm mount
The upper control arm mount is attached to a stronger structure that has been constructed using thicker, more durable, bend resistant, heavier gauge steel.