Learning curves affect horsepower curves, so as Javier Loarca can attest, with greater knowledge comes greater horsepower. Loarca had raced an all-motor pro class car for a number of years. There he learned about making power without boost or nitrous oxide. When his all-motor racecar was sold, he purchased this Civic EG hatch as a commuter in 2007. But a short matter of time brought him back to racing as he sought to do something a bit different. Not only would he embark on a forced-induction journey, he would do so with Honda’s newer K-series powerplant instead of the B-series he was accustomed to.
Text by Richard Fong // Photos by Michael Ferrara
The quest for big power and quicker times started under the hood. Despite the aftermarket being slow to embrace Honda’s K-series engine, Loarca was determined to power his EG with the new mill. He states, “I wanted to do something different. Honda’s B-series has had over 15 years of development and highhorsepower examples are not uncommon. But not many have gone very far with the K-series since it first appeared in the EP3 Civic in 2001. Building a turbocharged Kseries was a challenge that I looked forward to.” A 2.4-liter K24A2 block sourced from an Acura TSX formed the foundation of the build. RS Machine reinforced the block with ductile iron sleeves before boring the cylinders to the factory spec 87mm. A set of 9.5:1 compression JE Pistons filled the cylinders, making the connection to a Honda S2000 AP2 crankshaft by way of GRP aluminum connecting rods. The direct fitment of the S2000 crankshaft made the build straightforward and destroked the engine from 99mm to 90.6mm. The new displacement now calculates to 2,155cc.
HELP FROM LITTLE BROTHER
While Acura equipped the TSX with the larger K24 engine, the higher-flowing i-VTEC head from the 2.0-liter RSX reigns supreme in the world of K-series engines. Not only are the K20A2 ports larger, the i-VTEC functions on both the intake and the exhaust cams for maximum tuning flexibility. Loarca sourced a K20A2 head and reinforced the valvetrain with Supertech springs and titanium retainers. These improvements keep the valves from floating when engine speeds exceed 10,000 RPM. ARP head studs crush a Cometic MLS head gasket to ensure a good seal.