Enclosed within the cockpit of this EP3 Civic that was bestowed upon us by the mechanical masterminds at Signal Auto, we refrain from our jubilant reactions and giddiness brought forth by the combination of big boost and light cars. Instead, we scratch our heads and try and surmise as to why, after approaching three years of completion, this hatchback has no more miles racked on its odo than we could muster from a quick jaunt to Vegas and back.
Signal's '03 Si was built to answer the call of Honda and Valvoline's 2003 Civic Si Challenge, a magazine event in which readers called it the Si around (and best of the other entrants). Although the rules of the challenge were left open to some interpretation, the folks at Signal Auto deciphered them in the narrowest of ways: to build the meanest, baddest Japanese style street Civic ever to grace a U.S. interstate.
Approach the Civic from any angle and this is most apparent. From the cornea-damaging orange paint and wide, yet subtle body kit, to the colossal GReddy front-mount intercooler, this Si screams "race me and you'll lose."
To accomplish the task, the hatchback was shipped from the company's Torrance, Calif., facilities to their headquarters in Osaka, Japan, where the transformation took place.
Proof of the hatchback's street-dominating abilities lie underneath the multicowled Signal carbon-fiber hood. Per the rules, the factory K20 remains intact, at least internally. Power is stepped up to a healthy 374.6 hp to the ground, thanks to a GReddy TD06-L2 turbocharger mated to a custom-fabbed manifold constructed by Signal's own.
The inside is a different story. Despite the Civic's capabilities, the interior remains surprisingly stock. The headliner, dash, stereo, air conditioning, rear seats and carpet; it's all there. Aside from a pair of Bride racing seats and an assortment of GReddy gauges, little else indicates the true nature of this Si.
The best part is the Signal Auto Civic Si is a true, all-around street performer in every sense of the phrase. Unlike the 500-hp Civics we've encountered that commit themselves to blown-out shocks and brake pads long past their service limits, this Si leaves little to be addressed. It's a viable and well-rounded contender at any track, on most any terrain.
Just as attention was given to power production, so was it to harnessing that power in the form of traction and braking. Signal called upon Tanabe to fill the order. A set of the company's Sustec Pro SS coil-overs are bolted in place and ensure that weight is transferred in the right places at the right times.
An assortment of Tanabe chassis braces and anti-roll bars further ensure this Civic's handling prowess around any bend. According to the folks at Signal, adjustability is key. The Civic is able to go from highway to dragstrip to road course without any disassembly or parts swapping.
Still nestled within the confines of the Bride Zeta III seats, still scratching our heads and marveling at the apparent lack of mileage/enthusiasm over this Si, we're informed the powers that be at Signal are contemplating reverting the EP3 back to its stock state-or at least toning it down a bit.
It seems that between cracked exhaust manifolds, tire-annihilating boost runs, excessive torque steer, and a wide bulls-eye for the local police, this ultimate "street car" has failed in one small area: it's streetability.
But we'd gladly sacrifice a bit of that streetability for some of those tire-annihilating boost runs.
Bolts &WashersSignal auto's 2003 Civic si
Propulsion The factory K20 remains untouched internally. Responsible for the 374.6 hp to the wheels is a custom designed turbo kit. The star is a GReddy TD06-L2 turbocharger bolted up to a one-off manifold designed and built by Signal Auto. An Airinx filter directs incoming air into a custom-made intake tube meeting up to the compressor housing. A GReddy front-mount intercooler cools off the incoming charge and routes to the turbo through 2.5-inch aluminum tubing. Air exits the exhaust side of the turbo just before entering a Tanabe Ultra Medalion exhaust system and center-mounted muffler, also custom.
Ensuring that the stock K20 avoids a lean condition, Nismo 550cc/min fuel injectors reside in the stock location along with a SARD fuel pressure regulator and Bosch fuel pump. A plethora of Earl's steel braided hose and fittings keep the fuel inside the system despite high temperatures and pressures.
A Cusco limited slip differential housed inside a JDM Civic Type-R six-speed gearbox encourage traction. The duties of transferring power from the crankshaft to the wheels are answered with an Exedy single-diaphragm clutch and chrome-moly flywheel.
Rims & Rubber Up front, 18x9 Volk Racing Challenge wheels fill the fenders while out back a slimmer set of 18x8s get the job done. BF Goodrich g-Force T/A KD tires of the 225/40-18 variety serve as meats.
StanceTanabe handles suspension duties for front and rear strut tower bars, front and rear anti-roll bars and a chassis under brace. Tanabe Sustec Pro SS coil-overs fitted with the company's PRO210 springs handle damping.
ResistanceEndless slotted rotors bring the Civic to a halt with the help of six-pot calipers and pads. Endless brake lines at all four corners increase brake pedal firmness.
BodyBodywork was completed at Show Up, Signal Auto's chain of body shop in Japan. The Si was sprayed Show Candy orange and features custom graphics courtesy of Signal. All body add-ons are exclusively Signal, including the carbon-fiber hood, widebody fenders, front bumper spoiler, side skirts and carbon-fiber rear bumper.
InsideSave for the Bride seats and Simpson harnesses, the interior remains relatively stock. A few GReddy gauges monitoring vitals such as EGT, oil pressure and water temperature are dispersed throughout the dash. Tuning demands are met with an HKS F-CON V Pro engine management system. Boost is regulated with the help of a GReddy Profec B electronic boost controller mounted atop the steering column.