Known by most as the Stealth bomber represents a truly revolutionary piece of military aircraft design. Its stealth technology is intended to help it penetrate defenses previously impenetrable by combat aircraft, with its low-observability coming from a combination of reduced infrared, acoustic, electromagnetic, visual and radar signatures, making it difficult for defenses to detect, track and engage. Much of the technology it uses to go unnoticed remains classified, but what we do know is that the B-2’s composite materials, special coatings and ‘flying wing’ design (which makes it appear to be an insect on radar) contribute to its stealth abilities.
Kenneth ‘Turtle’ Lau is definitely someone who appreciates the value of flying under the radar. Having placed an order for this 2002 Nighthawk Black Pearl Acura RSX Type S before they were even scheduled to arrive on this side of the Pacific, clearly he was intrigued by this sports coupe’s clean and subtle styling. But not even Turtle himself could have realized that his relentless pursuit of race car performance in a street-legal package would result in a DC5 that is among the quickest and most stealth all-motor Hondas we’ve ever come across.
As a race mechanic, ECU tuner and test driver for Kensai Racing’s Grand Am Cup RSX Type S’s, it’s hardly surprising that Turtle tore his brand new K20A2 engine apart just weeks after taking delivery of his new ride, back in the fall of ‘02. Among the initial list of go-fast goodies he installed was a set of DC5 Type R camshafts and pistons as well as Mugen valve springs, N1 ECU and carbon fiber rear spoiler. In fact, the list of initial modifications made to his Type S engine before it even had a thousand miles on it was extensive, particularly in light of the fact that the aftermarket had only just begun to offer much in the way of go-fast goodies for the K20. Squeezing over 220whp out of this cleverly modified 2-liter, Turtle was clearly ahead of the crowd given that everyone else was just beginning to bolt up cat-back exhausts and cold-air intakes at this early stage in the K-series game.
A lot of people would have been satisfied with accomplishing so much so quickly, but not Turtle. He’s the kind of speed freak who never rests, always looking for new ways to wring extra juice out of his K-series and grip out of his DC5’s chassis. Having run a variety of different cams, programmable ECUs and bolt-on mods during his continuous pursuit of serious K-series power, in early ’06 he decided it was time to step up to Honda’s 4-cylinder ‘big block’. Acquiring a complete K24A2 longblock out of a scrapped ’04 TSX, his RSX now has an extra half-liter of displacement via the 1mm larger bore and 13mm longer stroke.
To take full advantage of the extra cubic inches provided by the K24, Lau had sponsor Web Cams make him a custom set of camshafts, while the valvetrain has been reinforced with Skunk2 valve springs and titanium retainers. The exhaust cam has been fine-tuned using a Skunk2 adjustable cam gear, while intake cam timing continues to be under the supervision of the iVTEC system and a Hondata K-Pro ECU. A set of .25mm oversized TSX pistons were also installed, after having the cylinders bored and honed for the slightly larger diameter pistons and rings. Completing the longblock upgrades is a knife-edged K24 crankshaft, K20 oil pump, and Hytech baffled oil pan. To protect his freshly assembled big block and optimize racetrack performance, Turtle also added an Earl’s 26-row oil cooler, since he’s found that the engine temperature creeps too high after about 20-30 minutes of track use with K-series engines. The Earl’s cooler has helped reduce oil temperature by 25 degrees, allowing for prolonged lapping sessions where Porsche owners are regularly left eating this stealth coupe’s dust.
Bolted to either side of this potent 2.4L mill is a Euro Accord RBC intake manifold and 64mm Accord throttle body and a Hytech Exhaust 4-2-1 stainless exhaust manifold. Further aiding the smooth and rapid expulsion of exhaust gases is a Hytech 3-inch cat-back exhaust system and muffler, giving Turtle’s RSX a deep metallic snarl for those unsuspecting Porsche owners to enjoy as he blows past them up the back straight at Mosport International Raceway.
Having become highly sought-after for his ECU tuning abilities, Turtle did a quick but effective tune on his RSX big block street beast that resulted in over 250whp and 200 ft-lbs of at-the-wheel twist. Transferring all this pump gas tuned grunt to a sticky set of Toyo tires – mounted on gorgeous bronze 17x8-inch Mugen MF10’s – is a JDM K20A Type R transmission equipped with a JDM CR-V 5.0 final drive, along with an Exedy chromoly flywheel and Stage 2 clutch kit. The stock Type R limited slip differential was also pulled in favor of a 1.5 way clutch-type LSD from KAAZ, an aggressive unit that transfers power more aggressively than the OE torsen-style diff.
Having won races and championships in a wide variety of motorsports from Time Attack to Touring GT, Turtle has plenty of experience making cars stop and turn as well as make big power. In the case of his street-legal DC5, a car that sees as much track action as it does city use, its suspension has received every bit as much attention as the powertrain. Starting with a set of Tein N1 double-adjustable dampers, spring rate choice was dialled in with the help of friend and Real Time Racing driver Pierre Kleinubing, who tested this RSX on highway on-ramps and any other twisty bits available, resulting in a 16 kg/mm front and 38 kg/mm rear spring rate choice. The astronomically high rear spring rates, which may surprise some, is a necessity to eliminate the understeer caused by the rear trailing arm design of the RSX, particularly how far inboard the location of the rear shocks and springs are. Rear roll stiffness has been further adjusted by a 27mm Hotchkis anti-sway bar, while front Mugen and Cusco strut tower braces and rear Cusco strut tower brace prevent suspension deflection during hard cornering. Further reducing unwanted changes to suspension geometry are custom heim-jointed front and rear lower control arms and trailing arm bushings. The front control arm heim-joints are offset, adding some much needed caster and associated cornering stability.
When you’ve built a RSX with a seriously powerful K24 and a full-out race suspension, brakes that are equally up to the task of heavy and repeated track use are a must. Turtle has addressed this area of his super clean speed machine by replacing the stock front brakes with 330mm two-piece rotors and 4-pot AP Racing calipers. The rotor hubs are custom billet pieces that widen the front track by 25mm on each side, just one of many small tuner tricks Turtle has used to overcome the handling deficiencies inherent to a McPherson front strut design. JDM DC5 Type R calipers are used on the rear of the car along with 310mm Project ? rotors that also have a wider offset, increasing the rear track by approximately 20mm on each side. Earl’s stainless steel brake lines, Motul RBF600 brake fluid and Hawk Performance DTC-70 brake pads combined with the upgraded rotor and caliper combination ensure that Turtle has race car quality stopping power with fade-free performance lap after Porsche embarrassing lap.
The interior of Turtle’s RSX has seen subtle and performance-oriented upgrades. Extremely rare black JDM DC5 Type R Recaro front seats – featuring large side bolsters and racing harness pass-throughs – replace the black leather Type S units. A Mugen suede-covered 360mm steering wheel and hub spacer provide improved feel and a superior driving position by moving the wheel 30mm closer to the driver. In place of the factory pedal covers are non-slip Mugen offerings that provide tighter pedal spacing for easier ‘heel and toe’ downshifts. A well-trained eye will also notice the Defi oil pressure and oil temperature gauges installed on either side of the main gauge cluster, but anyone unfamiliar with RSX’s stock dash would almost certainly assume these gauges are factory original given how seamlessly they’ve been integrated.
The sleeper theme continues on the exterior of this purpose-built RSX, where understated JDM upgrades are likely to be spotted by only the most educated of Hondaphiles. Black housing HiD headlights, amber corner lights and front lip and rear lips are all JDM DC5 Type R upgrades that subtly distinguish the car from a stock Type S. The lightweight carbon fiber hood has been paint-matched to keep the exterior looking stock, while Vision carbon fiber side view mirrors and a genuine Mugen carbon fiber spoiler give the all-black appearance package some texture as well as real aerodynamic benefits.
The end result of Turtle’s ever-evolving vision for his ’02 RSX Type S is a big block stealth bomber equally capable of cutting through traffic with four adults onboard, evading unwanted attention on the street with its blacked out exterior, and laying down lap times at his favorite racing circuit that rival full-blown race cars. Somehow, we think the engineers behind the B-2 Spirit stealth bomber would approve.