The EVO is a scalpel among butter knives. Hellacious, visceral and ball busting are a few adjectives that come close to describing the Lancer Evolution driving experience. As rewarding as the EVO is out of the box, few cars make more willing boost-up partners. Our mission is to take an '06 EVO IX and make pure, reliable power with a Zen-like balance of hardware and software, and do it in a highly cost-effective manner. Best of all, our endeavor will also show techniques that relate to modding almost every turbo car. Boost junkies, pay attention.
Flash Of Genius
With so much talk on the horsepower Mitsubishi left at the stable regarding the EVO's stock tune, we elected to flash tune our car while in stock form to illustrate what horsepower gains your car can achieve with a $200 flash tune alone [see side bar, next page]. English Racing's Lucas English and Aaron O'Neal served as a soundboard throughout the process, flashing our EVO's stock ECU to new power levels using Tactrix, EcuFlash and EvoScan. Tactrix is the hard-part connection to the ECU, EcuFlash is the software that talks to the ECU, and EvoScan provides in-depth datalogging of critical parameters.
"There has been a paradigm shift; the old way of piggyback fuel computers is obsolete," says English Racing's Aaron O'Neal. "With modern technology, the ECU works more like a flash drive you'd buy at Best Buy. We can download, examine and rewrite the stock chip virtually an unlimited amount of times before any issues arise. We have access to all the fuel, ignition and MIVEC maps, with full programmability and not just a percentage of this or that." A quick reflash and dyno tune netted our EVO with 274.5 hp and 267.8 lb-ft of torque-an increase of 8.5 whp and 3.4 lb-ft of torque over our. Upon completion, we re-flashed the ECU back to stock and broke out the wrenches to begin our budget build.
Cone Filters vs. Intake Kits
Why
There are four basic types of intake upgrades: drop-in panel replacements, add-on cone filter kits, short-ram kits, and cold-air kits. Sporadic idling has been attributed to short-ram and cold-air kits that replace the factory piping with hard pipe-if the hard pipe promotes vibrations that confuse the air meter, it can send a false signal. "Also, the length and shape of the piping affect how the air moves through the MAFS, and can cause a choppy idle, inaccurate fueling, can make the car stall-prone, etc.," says Lucas English. "If the short-ram doesn't have enough curve, or too much curve, it will affect the vortices in the MAFS at slower air speeds. The filter can also contribute to these problems. A closed, flat-top cone filter hinders vortices to the meter, while an open-top filter allows the air better access to the metering element. The Vibrant-type filter used in the Buschur add-on cone filter kit, and those included with AEM and K&N kits work awesome."
Verdict
Going with a cone filter on our EVO IX was one of its best mods. Think about airflow and the harsh effects of restricting it. With a few exceptions, drop-in panel filters can't match the flow capacity of cone-type replacements, and factory airboxes stamp out most audible evidence that you have a turbo under the hood-and who doesn't like to hear turbos spooling and bypass valves venting?
Using an add-on cone filter kit on an EVO has many advantages over a pipe-and-filter system, short-ram, or cold-air system. The bypass valves in EVO IXs are much improved over those in VIIIs and do not hiccup when the boost is increased. Since there is no need to upgrade the BOV, it makes sense to leave the stock piping intact. Most importantly, a cone setup is about a third of the cost of entry-level short-ram kits.
The Buschur Racing cone filter system was a snap to install, and audibly brought the car to life and pushed peak output to 280 hp-a 14-horse jump. A flash update netted an additional two wheel horses and smoothed the graph, offering 282 hp and 268 lb-ft of torque.