Ten years ago, if you had $1000 burning a hole in your pocket, the parts equation for power was simple: buy a cat-back exhaust, a new intake and if you had some extra scratch to spare (highly unlikely), you might be able to scam a used header off a friend. If you had a second job and sold an extraneous organ or three, you could cough up the cash for a hot set of cams and maybe an off-the-shelf turbo kit.
While that formula remains largely unchanged today, a fresh crop of factory turbocharged vehicles has taken that tried-and-true tuning approach and stood it on its head. As we've documented before, most manufacturers sacrifice outright performance at the altar of durability and fuel efficiency. With a few intelligent tweaks to the factory ECU, serious gains are lying in wait, ready to be exploited.
Shiv Pathak, Vishnu's founder and geek-in-charge, has turned his attention to the new Evo X and in the process has proven that the all-aluminum 4B11T/C has the potential to be just as potent as the workhorse that powered Evos of yore. Vishnu did a scope reading of the crank trigger sensor and found it provided a significantly higher resolution (32 -3) than the outgoing 4G63 engine. It's a similar situation with new Mazdas, Volkswagens and Audis, and makes replicating the signal far easier and more accurate.
Vishnu was able to adapt the PROcede system to the Evo X, which piggybacks off the factory ECU to manipulate the boost control solenoid, ignition timing and fuel duties. From there, the company headed to the dyno at Full Function in Union City, California, to spin the rollers and get some baseline performance figures before tuning got under way.
Strapped to a Mustang dyno, the stock Evo X put down a relatively low (but entirely predictable) 215 wheel-hp and 240lb-ft of torque while running California's 91-octane gruel. Under boost, Pathak found that the stock Evo runs incredibly rich, which is likely a move on Mitsubishi's part to make sure its engines don't go pop. After fitting the PROcede and doing some mild tuning, Vishnu was able to achieve a consistent 290 wheel-hp and 295lb-ft of torque to the wheels.
A three-inch high-flow catalytic converter and 'muffler shop special' cat-back exhaust (a production version is on the way) were then installed, coaxing out a few extra horses. But more importantly, torque output went through the roof, leveling off at 315lb-ft. While Vishnu leaned out the fuel mixture and retarded ignition timing, peak boost pressure hasn't changed. Boost still maxes out at the stock 23psi, but instead of dropping to 14psi when the engine reaches redline, the PROcede tapers boost to 17psi.
Cruising around town, the car feels virtually unchanged from its stock counterpart, except for a gruffer exhaust note and an occasional pop coming from the dual-tip exhaust. But flex the throttle above 2500rpm and the evolved X is a complete revelation.
Acceleration is beyond brisk-verging on violent-and never runs out of steam before bouncing off the rev limiter. Mid-corner, the throttle is less a method of propulsion and more an integral part of the suspension. Dip in halfway through a bend and the rear end loads up with confidence while the front tucks in and heaves the welterweight onto the next straight. This is the Evo that should have rolled off Mitsubishi's assembly line. Vishnu's PROcede system and plug-in harness costs around a grand, while a number of aftermarket three-inch exhaust systems already exist.
Pathak maintains that more gains can be had, but the Evo X benefits from a sizable stock catalytic converter and a factory downpipe that isn't nearly as restrictive as the units fitted to the Evo X's predecessors, so those extra ponies won't be nearly as easy to extract.