Of all the successive evolutions of the Lancer the most significant ones were the Evolution IV and evolution V. Introduced in the Evolution IV was an engine rotated by 180°, compared to the Evo III, so that the gear box was relocated on the left side were the driver sits. This positioning offered a better balanced weight distribution. This engine orientation was maintained on the Evo V and later models. The Evo V's main innovations come from a heavily upgraded engine management system, a relocated and upgraded intercooler, new aerodynamics, upgraded brakes and of course a totally redesigned suspension layout. This last point is, naturally, the most noticeable change in the Lancer. The front and rear tracks where increased by almost 4cm. The Evo V was clearly designed as a tarmac spec car. This fact denotes RalliArt's effort to keep up with the WRC class cars. A funny episode of the Evo V's young career is that the initial prototype which obtained FIA's homologation had wheel arches that were too small to fit the 18 inch rims of the rally spec car. Mitsubishi had to obtain the agreement of all the other WRC teams in order to modify this detail.
The street version of the Lancer Evolution V*
Let's look now, in more detail, to some of the modifications applied in the evo V when compared to the Evolution IV:
As mentioned earlier the new evolution V was designed, mainly, as a tarmac spec car. Mitsubishi and RalliArt have, however, redesigned many mechanical parts in order to allow changing them very rapidly. This fact proved extremely useful during the evolutions V's first rallies. The tracks have been widen by almost 4 cm (3.5 cm at the rear). The suspension attachment points have been relocated in order to allow more suspension travel. Suspension travel is still a problem though with only 163mm front and 160mm rear travel in tarmac spec. Bigger brakes have been fitted. The sophisticated, multi-link, rear suspension of the Evolution IV has been maintained. Additional welding points have been applied to the car's body which provide even more chassis rigidity to an already extremely rigid shell. Note that the new car can very easily be transformed to gravel spec. In this configuration it is, however, a little less agile than the Evolution IV was. Some suspension parts are now made out of aluminum alloy as are the bonnet and front wings!
The Lancer's Evo V rear differential
Not many differences here, mainly detail work. A self-locking front differential has been fitted in the front axle so now all differentials are self locking. The gear box ratios of 3rd, 4th and 5th gear have been shortened. The maximum speed the car reaches now is 180 Km/h. This is clearly a very short final ratio which favors acceleration. Although the Evo V gear box is essentially the same to the one used in the Evo IV all pinions have been reengineered in order to reduce the overall inertia and are now heat treated. The transmission oil circuit holds now a radiator to which is applied a water spray for additional cooling. Finally the mounting points of the rear differential on the chassis have been taken further apart in order to be able to cope with the additional engine torque.
Not that many changes here neither. The mechanical parts are essentially the same except for the pistons which were redesigned. The engine's bore has an additional 0.3mm mainly to improve on piston sealing and blow-by. The compression ratio has been lowered by 0.2 for improved reliability and to allow more turbo boost pressure without causing engine knock. The intake manifold has been shortened, as compared to the one on the Evo IV, in order to improve its gas flow characteristics in high engine speeds. A new, slightly bigger, turbocharger has been fitted (provided by the Japanese manufacturer IHI). The major change in this field is in the engine management system. The new ECU has now double the memory and processing power than the Evolution IV unit had. This allows for far more refined engine management strategies which now take into account many more parameters to calculate the correct fuel quantity and duration of the injection cycle. The new unit proves very useful in the rallying version of the car. A new and huge intercooler has been fitted and relocated just below the front bumper. A water spray projected on the intercooler provides additional cooling.
*:pictures are courtesy of Mitsubishi Motors Corporation in Japan