Guide: a 20 Year Celebration in Tokyo - a Historical & Technical Appraisal of the Honda NSX Mugen RR Concept
Background
To celebrate 20 years since the first generation NSX arrived in 1989, a sensational Super GT-inspired concept was created by Honda’s de facto performance subsidiary: Mugen.
Unveiled at the Tokyo Motor Show in October 2009, the Mugen NSX RR Concept was displayed four years after production of the standard model had been discontinued.
However, despite its ageing underpinnings, the wide-bodied Mugen RR stole the show and there was hope that a short production run would follow.
This latest machine was not the first NSX road car that Mugen had worked their magic on. Back in early 1992, the company had produced a mechanically and cosmetically enhanced NSX that, although destined to remain a one-off, yielded an array of hop-up parts that were subsequently offered to customers.
Unlike other tuners, Mugen’s special status with Honda comes down to family ties; Mugen founder Hirotoshi Honda is the son of Honda founder Soichiro Honda. Since his father’s death in 1991, the Mugen boss remains the Honda Motor Company’s biggest shareholder.
Having been created to offer tuning parts for Honda cars and motorcycles, Mugen went on to play a key role with the NSX competition programme. This most notably took the form of participation in the Japanese GT Championship which yielded three Team’s titles (2000, 2002 and 2004) plus a brace in the Driver’s category (2000 and 2004).
For 2005, the Japanese GT Championship was re-branded as Super GT to better reflect the Prototype-grade cars the series catered for; since 2003 the domestic Japanese series had essentially become a Silhouette formula where partial spaceframe construction, radical suspension and free engine / transmission positioning was permitted along with elaborate aero kits.
As hoped for, the new regulations had given a fresh lease of life to older models like the NSX and A80 Toyota Supra which could be heavily modified to stay competitive. To homologate a variety of new parts for the ‘05 season, Honda had produced the NSX-R GT, five of which were manufactured in February of that year.
When the Mugen RR was presented at Tokyo in 2009, the NSX was just about complete its final season in Super GT. Driving for Team Aguri, Ralph Firman and Takuya Izawa went on to claim second in that year’s Driver’s standings and fittingly won the car’s final race at Motegi on November 8th.
Chassis
Unlike every other NSX road car, the Mugen RR was based on a leftover Super GT platform which used an extruded aluminium central section to which lightweight aluminium spaceframes were added at either end. This meant the RR incorporated a longitudinally instead of transversely-mounted engine which improved weight distribution and lowered the centre of gravity.
Fully adjustable suspension was via double wishbones with coil sprung dampers and anti-roll bars at either end.
Enormous two-piece floating brake discs were fitted along with six-piston monobloc calipers up front and two-piece four-piston calipers at the rear.
The wheels were Mugen’s own 18-inch seven-spoke forged alloy items shod with Michelin Pilot Sport tyres. They were fixed in place with five lug nuts instead of the centre-lock type used in Super GT.
Engine / Gearbox
The engine was a Mugen-enhanced iteration of Honda’s all-alloy DOHC C32B V6. In standard trim, these high-revving 24-valve VTEC motors ran a 10.2:1 compression ratio and Honda’s own PGM-F1 electronic fuel-injection.
Precise details of the RR’s engine were never published, however, we do know it was equipped with uprated Mugen heads, individual throttle bodies and a carbon airbox with snorkel-type intake. Displacement was kept at 3179cc thanks to a bore and stroke of 92mm and 78mm respectively.
At the time, output figures of circa 380bhp were rumoured compared to 290bhp for the standard C32B engine.
No headers were fitted to the RR and nor was any gearbox; the Super GT racers used a six-speed sequential transaxle whereas the regular NSX ran a close-ratio six-speed manual. It was the latter type lever that appeared in the RR’s cockpit.
Bodywork
Cosmetically, the Mugen RR took most of its design cues from the 2008 NSX Super GT car.
The front end was an almost direct copy although it lack the tacked on corner sections adorned with their massive canards. The bank of louvres behind each light cluster were also absent and the car was actually a few inches narrower too.
The contoured front intake aperture was filled with a quartet of guides that fed cool air towards the brakes and radiators. Hot air was then dispelled through vents on the front-lid and gaping cavities where the front fenders met the leading edge of doors (which were sourced from the standard NSX).
Like those at the front, the rear fenders were dramatically extended compared to the standard NSX but not quite as wide as the Super GT racer. To smooth airflow around the car, the engine cooling scoops were deleted in favour of the aforementioned snorkel mounted through the rear window.
Located on the left-hand rear fender was an exposed aluminium fuel filler cap.
The huge spoiler mounted on twin pylons was unique to the RR and incorporated a high level third brake light. Further down, the RR featured a custom vented apron, the centre section of which was integrated with the rear diffuser and dual pipe exhaust.
Mugen opted to paint the RR Grand Prix White with the front splitter, side skirts, spoiler pylons and parts of the rear apron High Gloss Black to match the wheels.
Body panels were a mixture of carbonfibre and aluminium.
Interior
Inside, although most of the original NSX architecture was retained, Mugen gave the RR Concept a dramatic makeover thanks to an abundant use of bright red upholstery.
Red alcantara was used to cover the dash, the sidewalls of the centre console, the outer sections of the door panels and the rear bulkhead. New racing-style bucket seats had red alcantara bolsters and dark grey alcantara centres. Dark grey alcantara could also be found on the A and C-pillars, the door centres, the sills, headliner and the steering wheel rim.
The steering wheel itself was sourced from the latest Civic Type R albeit further customised with exposed carbonfibre spokes.
Instead of the usual six gauges, the RR’s instrument binnacle was home to just a pair of Mugen-branded analogue read outs set within natural aluminium bezels. On the left was a 9000rpm rev counter and on the right a 360kmh speedometer.
The rest of the car’s vital statistics were notionally accessible via a new LCD infotainment screen located on the forward section of centre console where the digital clock and air vents normally resided. Smaller fresh air vents were now located underneath the screen, below which was an entirely new bank of modern switchgear to control the AC and infotainment.
The rear section of the centre console was unchanged from the standard car. It featured a gear gaiter and handbrake handle trimmed in red-stitched dark grey alcantara.
Weight / Performance
Although no weight figures were ever published for the RR Concept, thanks to Mugen’s extensive use of lightweight components it likely tipped the scales somewhere between 1100kg and 1200kg (compared to 1230kg for a standard NSX Type R).
Supposing a 380bhp engine had been installed, top speed would likely have been in the region of 180mph with a 0-62mph time of around 4.5 seconds.
Summary
Unfortunately, no copies of the RR Concept were ever made and it merely served as a tantalising last hurrah for arguably Japan’s most iconic supercar.
Text copyright: Supercar Nostalgia
Photo copyright: Honda - https://global.honda/
