Back in Volume 92, we featured an Evo X which had a HKS Legamax Premium muffler, HKS stainless steel intercooler piping, an HKS de-cat pipe or test pipe and an EcuTek reflash. That black Evo gained a total of about 27PS at the wheels, which is a pretty decent gain for a few bolt on parts and an ECU reflash.
This time round, we have yet another Evo X on the dyno with roughly the same mods. This red Evo X also has an HKS Legamax Premium muffler, HKS intercooler piping and an EcuTek reflash. Instead of an HKS de-cat pipe, the owner of this Evo opted to go the custom made route with a full catback exhaust system from Torque Gear. The restrictive intake was also removed and replaced with a free flowing BMC CDA air filter.
This combo should serve as a rule of thumb for all car owners, which is to say, that when one starts getting mods to increase engine power, one should start with the basics first before moving on to more complicated stuff like cams, pistons and turbos. An engine is a big air pump after all, and by freeing up the intake and exhaust, more air and fuel is able to pass through the engine, which in turn helps it make more power. Sorting out the intake and the exhaust first also lays the groundwork for future mods.
For the intake, the owner chose BMC’s popular CDA air intake. Each BMC CDA air intake comes with its own cold-air-intake hose and all necessary clamps and mountings. BMC’s CDA is a true universal application and can be fitted to almost any car. BMC’s CDA air filter has proven its worth in the past when we tested a BMC CDA air filter on a Mark 5 Volkswagen Golf GTi. The Golf made an extra 5bhp at the wheels with a simple air filter swap!
HKS’ intercooler piping kit is made of aluminium and is 10mm larger than the stock rubber hoses. Unlike the stock 60mm rubber hoses, HKS’ 70mm aluminium piping kit is not prone to cracking or expansion under high boost. This kit improves and stabilizes boost pressure, as well as turbo response. Each kit comes with three polished inlet pipes, one polished outlet pipe and purple HKS silicone joints.
HKS’ Premium Legamax muffler is made of SUS304 stainless steel and features twin 110mm rolled titanium exhaust tips. The Premium Legamax muffler bolts on directly to the factory exhaust and is silent, with a nice, fruity exhaust note endowing the Evo with a more aggressive nature. The HKS mid pipe is also made of SUS304 stainless steel and improves exhaust gas flow by eliminating the catalytic converter.
ECUTEK’s reflash remaps the standard ECU’s fueling and ignition parameters without having to hack into the car’s wiring loom. The ECU can be easily accessed with a laptop via the car’s OBD socket, allowing the tuner (as long as he is equipped with the appropriate software), to access all of the ECU’s functions and alter them to his liking.
Last but not least, is the full catback exhaust system which was custom made by renowned exhaust system and metal fabrication specialists, Torque Gear.
This Evo X pushed out 261.03PS and 36.02kg/m of torque at the wheels in stock form, which is about right for a completely stock Evo X with the TC-SST transmission. With all the parts fitted and the ECU reflashed with EcuTek, this CZ4A managed 280.92PS and 42.08kg/m of torque. That’s an increase of 19.89PS and 6.06kg/m of torque.
Logically, you’d think that this Evo X would make a little more power than the black one from Volume 92. There are two reason why this isn’t so. First of all, this Evo X is a refurbished model which was brought in from Japan by a grey import dealer, while the Evo in Volume 92 was an official Mitsubishi import. Since the grey import car has higher mileage, it’s probably safe to assume that age has decreased the engine’s power output slightly.
Secondly, we suspect that the placement of the BMC air filter has a lot to do with the smaller power gains. The air filter is less restrictive than the factory item, but the filter’s intake hole is positioned right in front of the radiator, which means that the engine is sucking very hot air. And everyone knows that hot air is bad for power production.
This month’s Power Pages also goes to show that cars can be unpredictable creatures and that one mod on one car may not work all that well for another, even if they are the same make and model.
BMC CDA air filter
HKS Intercooler Piping Kit
HKS Premium Legamax muffler
Torque Gear custom catback exhaust system
Call for price
N1 Racing (HKS) – 03-5636 5557
UHP Racing (BMC) – 016-380 2801
Torque Gear – 012-376 1333