Say You Want An Evolution
Few cars have the cult-like following of the Mitsubishi Lancer Evolution. One interesting aspect of the vehicle is that it is not only a tuner's dream, but a tech tour de force.
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The Mitsubishi Lancer Evolution began life in 1992, explains Mike Evanoff, manager, Product Strategy, Mitsubishi Motors North America, as a vehicle that underwent the required homologation to participate in the World Rally Championship series of races. Or said more simply: It was not a car setup to be a daily driver unless, of course, your commute had something to do with points between Paris and Dakar. Up until now there have been three generations, or platforms, and three models each: 10/92 to 2/95; 8/96 to 1/00; 1/03 to 8/06. Of the previous nine models it wasn't until model year '03, or Evo 8, that the car was available (dealership-wise, anyway, as this is the kind of car that people really do plenty to get) in the U.S.
Now there is the fourth generation, Evo X. "It was a clean-sheet approach," Evanoff says, explaining that they took advantage of the new global Mitsubishi GS platform that is also used as the basis for the more quotidian Lancer sedan and the Outlander SUV.
There are two Evo X models: GSR and MR. This is based on a strategy to move the vehicle beyond the historic rivalry with the Subaru WRX. The BMW M3 and the Lexus IS-F are two of the vehicles that Evanoff mentions as those which could lose some sales to the MR mode. But that might miff some of the stalwart zealots that have long supported the car. So of the two, the GSR is, Evanoff says, "louder," as it has less sound-deadening material; "has a harsher ride," through the tuning of the suspension and Bilstein shocks and Eibach springs; has the dynamic handling system (S-AWC) switch on the steering wheel rather than the IP to facilitate deactivation; has a manual five-speed transmission. Which means, by contrast, that the MR is quieter (it uses 11 pounds more sound insulation material), has a less-harsh ride (the Evo may be going somewhat mainstream, but in its context, it is mainstream like the canals on Mars), has the button slightly farther out of reach, and is equipped with a six-speed transmission that Evanoff describes as being the most significant development for this new model.
It's called the TC-SST, or Twin Clutch Sportronic Shift Transmission. It is an automated manual, which means that it can be put in "D" and left there or the driver can use either the console shifter or magnesium steering wheel shifter paddles. The transmission, which is said to be less complex than a conventional torque converter automatic transmission, has two electro-hydraulically operated wet multi-plate clutches. Evanoff describes the setup as essentially two three-speed manual transmissions. The odd- and even-number gears are on individual input shafts and linked with a transfer gear; one clutch handles a set of gears. When one gear is engaged, the next gear is preselected, ready to be engaged by the other clutch. The torque handover from one clutch to the other is done in a seamless manner. In addition, there are three selectable drive modes—Normal, Sport, and S-Sport (smooth, quicker, take-it-to-the-track-shift-shock)—each of which has a shift map. Inputs from the engine, steering, wheel speed sensors, and S-AWC (Super-All Wheel Control) are used by the transmission controller to determine the shifts. As the engine and transmission controllers and other sensors are networked via a CAN bus, the TC-SST performs with no noticeable lag.
The five-speed manual transmission is new, too. Compared with the previous five-speed, it has higher torque capacity. This means that the gear face widths are bigger than the previous. While this would ordinarily require a longer transmission case, to keep it compact (actually 6 mm shorter than the previous five-speed), they've eliminated a dedicated reverse gear. To get a reverse "gear" 1st and 3rd are meshed via using synchromesh to synchronize the idler gears between them.
Another significant change for Evo X is the first all-new engine since the car was introduced in Japan 16 years ago. The original engine, the iron-block 4G63 T/C, had been available in the U.S. prior to the Evo's availability here in the first two generations of the turbo Eclipse and the Galant VR-4. The new turbocharged and intercooled engine, designated the 4B11 T/C, has a cast-aluminum block that is specifically reinforced for turbocharging. It features a semi-closed deck structure, integrated ladder frame, and four-bolt main bearing caps. There was focus on making the engine compact and light. So, for example, the cylinder head is aluminum, and there is a direct-acting valve train, which means the elimination of the rocker arm assemblies. The cam shafts are hollow. The pistons are high-strength aluminum gravity castings (the con rods are reinforced forged steel). The forged steel crankshaft is cross-drilled. The stainless steel exhaust manifold is located at the rear of the traverse-oriented engine in order to help optimize weight distribution (and it also helps (1) speed the light off of the catalysts and (2) permits the use of a flat suspension cross member rather than the saddle shape that was previously required for exhaust routing). Oh, yes, and the 4B11 T/C produces 291 hp @ 6,500 rpm and 300 lb-ft of torque @ 4,400 rpm, both of which are improvements versus the previous powertrain.
Evanoff says that there was particular attention paid to not only weight reduction but weight distribution. The roof, hood, front fenders, and the front and rear bumper beams are aluminum. This, he explains, helps provide a lower center of gravity for the Evo. The battery and the windshield washer fluid tank are located in the trunk, thereby contributing to better fore-and-aft weight distribution.
Structurally, the Evo X is much torsionally stiffer than its predecessor. It is 39% better in twist (4.1 MNm2/rad) and 64% better in bending (5.4 MNm2/rad). High strength steels are used in both the B-pillar structure (980 MPa) and side sills (590 MPa). Additionally, there are other stiffening details, such as a V-shaped brace behind the rear seat.
The car features four-wheel independent suspension. The front has heavy-duty inverted MacPherson struts. The car borrows the flat cross members used for the Outlander SUV and then reinforces them so that the cross-member rigidity at the lower-arm attachment is 40% stiffer than the Evo IX. There are forged suspension knuckles. The rear suspension is a multi-link design.
The Evo is not a big seller. Evanoff suggests that sales will be on the order of 5,000 per year. But if one was able to factor in the level of enthusiasm of Evo owners and use that as a multiplication factor, the number of units is much, much larger than the 5,000 would indicate.