By: Charles Juckett, Matt Freeman
Photos: Charles Juckett, James Tate, Mitsubishi, Subaru

Day 1, Arrive and Dyno

Evo X Technology Explained

AYC or “Active Yaw Control” is a feature of the Evo X that uses an active rear differential to transfer torque to the wheels that have the best grip. Unlike traditional limited slip differentials, AYC is electronically controlled by measuring inputs from various accelerometers in the vehicle measuring. These include longitudinal and lateral g-forces, steering angle, brake application, and throttle position. The AYC advanced power application system accomplishes its task by controlling two hydraulic clutches that can limit torque on individual axles. Unlike traction control systems, AYC is a performance-oriented system that aims to increase cornering speeds. In the Evo X, it helps equalize the loading of all four tires, providing maximum cornering potential, while reducing understeer by transferring torque to the rear wheels. Super-All Wheel Control is the name given to the advanced full-time all wheel drive system found in the Evo X. S-AWC incorporates continuously updated data from the ACD (Active Center Differential), AYC (Active Yaw Control), Active Stability Control (ASC), and the Sport ABS systems to increase drive power, cornering performance and vehicle stability regardless of driving conditions. By actively determining cornering dynamics on a real-time basis the system operates to control the vehicle in a way that more closely mirrors driver intent.

Despite the early flight and the kid who incessantly bombarded my seat with his feet, I was excited about the weekend ahead. I would soon meet Ali (SPT) and James Tate (Author of “The Inevitable Evolution”) out in California to test 5 very different cars. Well, ok, three were Lancer Evolution X’s and the other two were ’08 WRX STI’s, but it wouldn’t take long to discover how diverse of a group it really was. Ali had arrived earlier and acquired the stock STI from the Subaru facility. Shortly thereafter he picked me up from John Wayne Airport and after the long flight, lunch was the first priority of the day. After we ate it was time to head over to Mitsubishi, where we finally got our hands on the stock GSR and the new MR. We were introduced to the two cars and almost immediately we recognized the GSR was the same media trackwhore used by many magazines in the industry. Glad that we got a car that was finally broken in it was time to set off to XS Engineering to get dynoed.

One by one, we got the cars strapped to the outdoor Dynamic Test Systems Dyno. We dynoed the GSR first and it put down 268 AWHP, near what was expected on this particular dyno. Next up was the Subaru, which pulled 273 AWHP, besting the Evo. Finally, we tied down the MR, which read a mere 246 AWHP. We were surprised at first with the low consistent number from the MR. After consulting with Mitsubishi about the issue, it was concluded that the ‘too-smart for the dyno transmission and half-dozen ECU’s determined that the front and rear rollers (not connected) were spinning at different speeds and interpreted this difference as an absence of traction, subsequently dialing back power. Even with the low numbers, our experiences over the rest of the weekend suggested the MR had the same amount of power as the GSR.

After our long day of travels and dyno pulls, it was time to hit the sack early for the big day tomorrow.

Day 2, On the Street
Eyes still half closed, we met James at a gas station on California Highway 2 just before 6:00am. This location marked the entrance to a twisty and sometimes treacherous stretch of canyon road outside LA better known as Angeles Crest. For us, it was an all too convenient shortcut to our Speed Ventures track-day at the Streets of Willow. As we headed up the hill it seemed as good a time as any to get used to the different cars in a careful, but spirited, manner on the canyon run.



Evo X GSR
Although the Evo VIII and IX were great cars, the new GSR stood apart from its older brothers. It was heavily refined and it felt better all around. It still lacked the interior finish typical of other cars within its price range; however, the recent changes are a marked improvement. The suspension was firm over bumps but not jarring and the noise was reduced from previous renditions. It was noticeably louder than the MR due to a lack of a 6th gear and 16 lbs less sound deadening. The stereo had respectable bass response, which is a compliment for any stock audio system. The 4B11T engine was responsive but lacked some bottom end grunt. When the boost-induced torque came on, it was noticeable, but not earth shattering. When on it, however, the extremely free-revving 2.0L inline 4 had smooth predictable power delivery all the way to its 7k redline.

Aside from being heavily fortified, the new 5-speed manual of the GSR had a good positive feel and position. Shifting was not laborious and the clutch was medium-light. Pedal position was slightly more spread apart as compared to older Evo’s, possibly to accommodate drivers with wider feet. As in the MR, the mechanics of the car were reinforced by traditional and satisfyingly crisp “Evo” steering. The brakes were what one would expect and provided excellent linear stopping power, exceeding the needs of anything you would encounter on a public road. Unless you get yourself in a sticky situation, you will probably not overtly notice the AYC (Active Yaw Control)/S-AWC(Super All Wheel Control) on the street. The car felt incredibly well executed and whether at 20 or 65, the chassis, steering setup and drive train seem to beg you to go just a little faster and turn in a little harder.



Evo X MR
In the MR, the subtle outward differences with the GSR were obvious. The MR was finished off with dark grey accents and chrome trim, while the 18x8.5” BBS wheels were a great fit that few would complain about. The new MR upholstery and trim upgrades brought the interior to a whole new level. The seats were firm and provided fantastic lateral support. The base stereo in the GSR was more than adequate, but the premium stereo/navigation in our MR put out sounds the previous model could only have dreamed (easily the best out of our OEM trio). While it does take a hefty hit on the wallet, the price seemed a tad more justified with the extra refinement. The navigation system was quick and intuitive. It worked flawlessly throughout the entire weekend, however, could be further improved by incorporating the existing phone system’s voice recognition.

When driven docilely, the MR was comfortable and quiet. The upgraded Bilstein/Eibach suspension was taught and proved more comfortable than the GSR and on par with the STI. If anything, I wouldn’t have minded a bit more growl from the exhaust.



Get stuck in traffic and the full automatic mode on the SST transmission will have you thinking that you’re driving a regular slush-box sedan. This was ideal for urban areas and proved useful in traffic. Decide that you want to have a little fun, flick it into manual mode and move into “sport” and you call all the shots. Through the hills of Angeles Crest, manual mode shined strong on the SST. Sure, it was hard to replace the sensation of a good heel-toe shift, but Mitsubishi did their homework and came up with a great alternative. Matching the transmission, steering and suspension were so precise that I got the sense of what the car was going to do before it happened. That level of predictability made the Evo X MR an incredibly easy car to drive. When combined with the adequate power that it shared with the GSR, the Evo X MR handled most situations on the road with drama-free ease. The MR was truly a multi use car that anyone can drive. If it were not for the laughably small trunk (slightly bigger than that of a Miata), this could arguably the best compromise of all worlds.

08 STI
Outfitted with silver BBS wheels and beautiful graphic grey metallic paint the STI’s new exterior had a more muscular look. We all agreed that the new design took the win for best appearance out of all 3. The interior also got the nod for highest quality and most improved color scheme. Grey alcantara and black leather replaced the econo-racer black and blue of the past. Additionally, the dash design and materials made huge leaps possibly exceeding that of the Evo X. While the new STI hatchback didn’t seem particularly large from the outside, the deceptively large boot swallowed up the three large carry-ons at the airport with room to spare, without folding down the 40/60 split rear seats. All weekend, we marveled at the STI’s remarkable daily utility. The backseat had even been enlarged to comfortably fit adults. Like the rears, the front seats were more comfortable, however were severely lacking in lateral support. By far the biggest interior downside was the optional navigation system (ours was a preproduction model). To use one word to sum up our Navigation experience, “grueling” would come to mind. In addition to freezing up completely a few times, it was particularly picky about how a destination address was inputted. Nevertheless, the all new STI was clearly the most suited and comfortable for daily use.

The chassis on the STI was completely revised and strengthen to accommodate the increased performance. Inside the large rear flares resided a completely new double A-arm rear suspension which both improves comfort and the camber curve to maintain the maximum contact patch. More poised and comfortable over uneven surfaces, the STI no longer seemed bothered by mid corner bumps making it extremely stable. While the steering weight felt decent through the canyon switchbacks, the feedback was still a bit lacking. A quicker steering ratio as well as increased feel would provide a more intimate driving experience.

Rolling onto the right pedal, we noticed the power band had been slightly increased due in part to the new dual AVCS (variable cam timing). The potent flat-four’s power is still delivered through the stout 6 speed with a tight precise shift pattern.

Before we knew it our canyon run was over all too soon. Luckily, we were only a few minutes from the track.

Day 2, On the Track
When we arrived at Willow Springs Raceway, it was only 7:45 AM, but we were wide-awake. We made our way over to the two Robispec cars waiting for us in the pits. After setting the car up with transponders and camera gear, Ali and I headed out onto the track for a couple of laps.

For our testing, we were running the Streets of Willow, a challenging and fun 1.8 mile road course in the faster counterclockwise direction. Streets boasts numerous elevation changes and a wide variety of corner types to fully test the cars’ handling.

Evo X GSR (On Track)
The GSR was completely in its element; engine, chassis, brakes, steering, and cockpit layout all complimenting each other. Around the first corner I quickly realized that the AYC was less than discreet. I tested the system by running too fast into a medium-tight lefthander (causing the car to go wide) at which point AYC kicked in by allowing the rear to push out in a controlled fashion. It felt as if someone gently picked up the rear of the car and set it down again once back in line, taking away understeer. Had I tried this same hot entry in an old Evo, or even in the new STI, I would have found myself missing the corner exit entirely. The S-AWC was less dramatic, but helpful none the less, enabling a far faster/better line in Tarmac mode than others

The only flaw in the AYC happened to be its greatest strength. The system was a fantastic and high tech solution towards improved cornering. It accomplished this by swinging the tail out, however in a slalom section or other area with quick transitions, resulted in overcompensation.

The larger brakes on the Evo X seemed to provide similar feel and stopping power to those found on previous models, but with better fade prevention. While the GSR had a solid front rotor to the MR’s 2 piece, it was hard to decipher the difference it made.

08 STI (On Track)
Out of the pits, the STI pulled strong with a flat torque curve and was a nip quicker than the Evo up to about 85mph. Much like the MR, the STI required selecting the Sport # ECU setting and disabling the traction control to get the most out of it. The end of each straight showed another great strength for the STI. Despite a smaller diameter, the brakes were absolutely fantastic both in feel and power. Entering the corners, the chassis was balanced and stable with minimal lean. The new Dunlops on the STI actually seemed to improve a little when they got warm. At the limit, the STI did display textbook understeer without a hint of movement from the planted rear. Attempting to limit the front end push, we set the DCCD to Auto Minus (rear biased power delivery) and applied a liberal amount of trail braking. The increased grip out of the rear with an understeer happy front proved to be the main performance deficit for the STI on the track. In the end, this simply prevented us from being able to carry the speed through corners that the Evos could. In quick transition, slalom-style corners, the STI shined.

Subaru STI Technology Explained

VDCS is short for “Vehicle Dynamics Control System”, the name Subaru gives to its traction control system. Like other Electronic stability control systems, VDC is a technology that improves the safety of a vehicles handling. It monitors wheel spin and steering angle to help prevent skids, helping the driver maintain control of the vehicle. VDC can assist a sliding vehicle by applying the brakes to individual wheels, or by reducing engine power to the wheels. There are 3 setting for the VDC, “VDC normal,” “Traction,” and “Off.” Normal provides the highest level of system engagement, utilizing all traction control function. The traction setting is more performance oriented with less restrictive stability control intervention and the engine torque-reduction system switched off. Off mode disables all VDC traction control functions. DCCD stands for “Driver Controlled Center Differential,” a manually or automatically controlled torque diverting system that Subaru features in the 2008 WRX STI. The system employs planetary-type differential gears with a nominal 41:59 torque split. A mechanical limited-slip type center differential augments the electronically controlled differential to enhance torque transfer performance. Steering sensor input, brake application, wheel slippage, and cornering forces enhance torque transfer response by actively relaying the car’s cornering situation. DCCD has 3 modes in the ’08 STI, “Auto,” “Auto (-),” and “Auto (+).” The Auto setting is the same as in the previous STI, while the new Auto (-) option shifts torque bias to the rear and opens up the center LSD which improves steering feel. Auto (+) tightens the center LSD, which is useful when driving on gravel or snow. The Six manual settings also remain which allow the driver to vary front-rear torque distribution by driving condition. Si Drive – Derived from the Legacy, Si drive allows the driver to select between three different ECU maps to regulate throttle response, efficiency, and power. The standard mode “S” provides a sport map for normal or spirited driving. S# quickens throttle response for high performance driving. “I” or intelligent mode limits power output for low grip conditions.

Evo X MR (On Track)
We had high expectations for the SST on the track as it had performed flawlessly on the street. In ‘super sport’ mode, the throttle response and gear changes were instantaneous. Super Sport was the only option for the track in addition to turning off the traction control. Approaching turn one from the high-speed straight made everyone feel a bit like Schumacher. The stable braking force and lightning fast downshifts gave the MR that F1 car sensation.

When set into full automatic ‘super sport’ mode, the computer took complete control and sometimes even revealed faster lap times. It was reassuring when the car matched my intuition, completing upshifts and perfect downshifts at what seemed to be just the right times. The SST was a technological marvel that allows the driver to refocus their attention elsewhere, but there was no denying that it took out a level of driving involvement. We should also note that the SST took a little getting used to, as there wasn’t the constant tactile reminder of gear selection one gets from a standard H-Gate. The MR’s super transmission was a crowd favorite and it continued to impress throughout the day.

The Bilsteins helped keep up the pace during high speed sweepers that seemed to scrub speed in the other stock cars. The suspension setup felt a little softer than the system found on the GSR, but it was by no means too squishy. Although slightly heavier, the additional weight over the GSR did not seem to have a noticeable affect.

Finally the time had come to test the Robispec Evo X GSR and the Robispec 2008 STI that had been patiently waiting. Each car had been treated to a custom RobiSpec set of coilovers, custom track oriented alignment, and exhaust modifications. Additionally the STI was treated with a different set of anti-sway bars. We didn’t get to drive either on the street, but being track cars, we didn’t miss much.

RobiSpec 08 STI (On Track)
The modified STI boasted a heavily altered alignment and balance that we hoped would rid the annoying understeering tendency that plagued the stock vehicle. I only got to drive it on street tires that didn’t prove useful given that it was specifically setup for ultra sticky R-Compound Nitto NT-01’s. On street tires the car was a little easier to rotate into the corners and was faster around the sweepers than the stock version. The balance however seemed a bit off and took a bit of getting used to. One noticeable improvement was the counterintuitive ability to steer under throttle. A calculated increase in throttle on the Robi STI actually brought the car more in line, which was a complete opposite of the stock car. When Ali got behind the wheel he felt the modifications helped instill greater driver confidence and the Robi/KW suspension was a good fit. The Robispec STI had a lot of potential and with a little further tweaking it could really improve.

RobiSpec Evo X GSR (On Track)
The modified Evo X GSR had a lower center of gravity that provided increased stability and even flatter cornering than the stock version. The tuned Evo displayed the same balance as the stock GSR. AYC still worked its magic, but it seemed far less noticeable. The experience was not subdued, but predictable and encouraging. All who drove it agreed that they wanted more time behind the wheel.



Track Times
Since Ali nor I are pro drivers by any means, we had a far more accomplished driver by the name of Emile Bouret to stand in as our “Stig”. As it faded into mid-afternoon it was time to get the more quantitative data. This is where Emile came into the equation. The track and weather were ideal, making the conditions close to perfect. We were pressed for time, but made our best attempt to control what variables we could so Emile could put down consistently fast lap times that highlighted the true upper limits of each of the 5 cars using GPS data acquisition courtesy of Neil Chirico.



Lighting the brakes on fire (literally in one car), Emile’s lap times in each car plummeted compared to what we produced earlier in the day. With the STI up first screaming off a 1:30, we briefly wondered if it had just shown up both Evos previous 1:31 best. They were shortly redeemed; both dropping into the mid 1:28’s with the MR just barely getting the edge. With the OEM pecking order settled, the RobiSpec cars were both taken out in turn. Up first the Evo put down an impressive 1:27. While a one second improvement may not sound huge, one has to consider how good the starting point was and with mainly just suspension improvements. The tuned STI almost matched the RobiSpec Evo time (1.27), however with the use of the NT-01 race rubber it was setup for. We estimated this to be a 1.5-2 second advantage, which would be inline with the expected level of improvement.

Conclusion
Leaving the track and the Robispec cars behind, we started our trek back to LA. We dropped the cars off at Mitsubishi at around 8pm and caught the next flight back to the east coast.

In the end, each car has its pluses and will appeal to different people. Both Evolution X’s offer a truly “Evo” driving experience, that is both entertaining and fulfilling. The STI however offers unbeatable utility, a good looking polished package, and real world useable performance. For either the aftermarket is right there with solutions to increase the performance of whichever you may choose.



Interview with the Pro (Emile Bouret)

Emile found the Evo X GSR the most fun and most involving driver’s car. The MR was great as well, and the gearbox was phenomenal, but lacked level of direct control that comes with a three pedal setup. He commented on the smoothness of the SST and confidently stated that it was at least as good as the VW DSG. Being a bit old school, Emile would have preferred the small jolt that comes from a true sequential manual transmission such as found in the Ferrari. He feels that the physical feeling of a gearshift adds to the experience and makes the whole car feel more alive. Emile added that the SST transmission of the MR would allow a less experienced driver more time to keep their head up and focus on improving other aspects of driving which could help expedite their learning process. Still all will enjoy the utility, speed and precision of the SST.

He did however find the Evo X to be less focused than its older counterparts feeling a bit “Playstation”, but this kept with the more mature feeling of the new car. While the X’s suspension is softer and provides a more comfortable ride, Mitsubishi did their homework as it performs just as well. This is achieved in part by the new AYC system that Emile lauded time and time again. He found that it instilled a huge level of driver confidence that aids novices and pros alike.

The STI felt slower around the track than both stock Evo’s but its power-band had more surge when getting on it, which was a plus. He noted that the STI also had the better feeling manual transmission and the strongest stopping setup. By the end of his hot-laps Emile had figured out how to use the brakes on the STI to get around the turns faster than we thought possible. Despite the abuse that the car took in stride, Emile ultimately complained of the same difficulty we faced in rotating the STI into corners as well as a lack of steering feel/feedback. He wished that Subaru would have displayed a greater level of confidence in their US buyers and he was disappointed that we were supplied a car that lacked adjustability and was so prone to understeer in stock form. While it is a safer setup, this takes away the fun of being able to drive fast.

Both the Evo’s and the STI’s pedals were slightly farther apart than previous which increased the difficulty of heel-toe shifting. Both cars also had sophisticated differential systems that helped put the power to the asphalt. Subaru’s DCCD system had more automated modes than before. This made a difference, but it would have been nice to have the ability to create an even greater rear-bias for the track. The Evo X manages to seamlessly transfer power, which lacked in the older Evo’s. While he appreciated the lack of turbo lag in all cars, he would like to see more turbo punch which is something that can be taken care of in the aftermarket.