Test & Tune: 2011 Mitsubishi EVO X GSR | Big Power Gains for the 4B11

THE DYNO

Royal Purple used on this EVO X

Prior to taking the car to the dyno, we performed the vehicle’s first oil and filter change. As the EVO X requires synthetic engine oil, we chose to fill our 4B11T with Royal Purple’s XPR 5W30. A Royal Purple oil filter was also chosen for the service. We selected COBB Tuning SoCal and its Mustang Dyno all-wheel drive dynamometer for our test and tune session. Having the tuner and the dyno facility under the same roof ensures consistent dyno numbers across the entire Test & Tune procedure from beginning to end. With the car strapped on the dyno, the EVO turned the rollers to the tune of 264 whp and 292 lb-ft of torque with maximum boost peaking at 22 psi.

In order to maximize the power output potential of the forthcoming parts, we installed the COBB Boost Pill and fine- tuned the result with the COBB AP first. The Boost Pill raised the maximum boost output of the factory turbo to spike at 27 psi. With COBB Head Tuner Jon Drenas modifying the fuel and ignition maps via the AP to better handle the increased boost pressure, the EVO X put down 300 whp and witnessed an increase of 23 lb-ft of torque.

With the tuning solution and boost control in place, we next installed the Cosworth Cold Air Intake. The Cosworth unit had an excellent fit and finish and installed without incident. We strapped the car back on the dyno and Drenas again used the COBB AP to optimize the map tables for the increased boost pressure and intake air flow. This time, peak horsepower checked in at 309 whp with peak torque increasing to 321 lb-ft, with the maximum boost pressure holding steady at 27 psi.

The next part up for installation was the TOMEI POWERED Expreme Ti exhaust. For maximum potential power measurement, we also chose to remove the included silencer before testing. Back on the rollers, Drenas ensured proper air/fuel ratios and optimized the output potential of the exhaust with the COBB AccessPORT Race Pro tuning software. Peak torque checked in at 328 lb-ft, a 7 lb-ft increase that manifested in the upper regions of the powerband. Maximum boost pressure remained at 27 psi but horsepower output increased 19 whp to the tune of 328 whp peak.

The final installation on this part of the Test & Tune was the TOMEI POWERED titanium straight-pipe. In addition to removing the restrictive catalytic converter, the titanium pipe also contributes to the overall weight savings over factory parts. With the TOMEI POWERED pipe in place and the EVO back on the rollers, peak boost pressure increased by 0.5 psi to 27.5 psi. Consequently, peak horsepower increased 7 whp to a peak output of 335 whp while peak torque also increased, checking in at 337 lb-ft.Engine bay of an EVO X