Honda NSX

The Honda NSX, marketed in North America as the Acura NSX, is a two-seat, mid-engine sports car manufactured by Honda.

The origins of the NSX trace back to 1984, with the HP-X (Honda Pininfarina eXperimental) concept, which was a mid-engined 3.0 L V6 engined rear-wheel-drive sports car. Honda committed to the project, with the intention of meeting or exceeding the performance of the then V8 engined Ferrari range while offering reliability and a lower price point. The concept thus evolved and had its name changed to NS-X, which stood for "New", "Sportscar" "Unknown world" (the X was a reference to the mathematical symbol X, which stands for an unknown variable), although the production model was launched as the NSX.

Gordon Murray, the designer of the McLaren F1 supercar, stated that he used the NSX as the inspiration for the F1 after test driving many high performance cars and finding the NSX chassis performed the best. Murray stated that the design was “monumental” to sportscar design. He found that the car could easily have handled more power and attempted to convince Honda to develop a more powerful engine, but they declined. This resulted in Murray developing the F1 with a BMW engine, but he was so fond of the NSX that he bought one for personal use and drove it for 75,000km. Murray stated that the NSX was “dear to his heart”.

Development[]

Around 1984, Honda engineers began experimenting with different engine and chassis layouts to test viability for future products. One of the test mules was a Honda City that had been cut in half, with the engine installed behind the driver's seat and powering the rear wheels. Although the project was not developed any further, many of the engineers were inspired by the exciting laps around the company parking lot in the mid-engined City. This experience, in part, convinced Honda leadership that the company should consider developing a pure sports car. As a result, in 1984, Honda commissioned the Italian car styling house Pininfarina to design the concept car HP-X (Honda Pininfarina eXperimental), which had a C20A 2.0 L V6 engine in a mid-mounted configuration. After Honda committed to a sports car project, the company management informed the engineers working on the project that the new car would have to be as fast as anything coming from Italy and Germany. The HP-X concept car evolved into a prototype known as NS-X, which stood for "New", "Sportscar" "eXperimental". The prototype and eventual production model—which was marketed as the NSX— were designed by a team led by Honda Chief Designer, Masahito Nakano, and Executive Chief Engineer, Shigeru Uehara (who were subsequently placed in charge of the S2000 project).

The original performance target for Honda's new sports car was the Ferrari 328 (and later, the 348) as the design neared completion. Honda intended its sports car to meet or exceed the performance of the Ferrari, while offering superior reliability and a lower price. For this reason, the 2.0 L V6 engine utilised in the HP-X was shelved and ultimately replaced with a significantly more powerful 3.0 L VTEC V6 engine. Over the course of development of the NSX, many engines were used, ranging from the 2.7-litre single overhead camshaft V6 engine from the Honda Legend/Honda Coupé to the 3.0-litre single overhead camshaft V6 engine, used subsequently in 15 test mules. Honda eventually settled on a non-VTEC, 3.0-liter double overhead camshaft 24-valve V6 engine selected for the production model. This engine generated a maximum power output of about 250 hp (186 kW; 253 PS) and 282 N⋅m (208 lb⋅ft) of torque, with a redline of 7,300 rpm. However, at the same time, Honda was working on its revolutionary VTEC variable valve timing system, with plans to release it on the company's home-market 4-cylinder Integra. Honda's then-president Tadashi Kume, himself a highly-skilled and respected engine designer, questioned the NS-X designers' logic in foregoing the VTEC system for Honda's new flagship sports car, while it was being used on the lower-market Integra. As a result, the engine was redesigned very late in the development process "to achieve the desired levels of performance and durability"; Honda designed a new cylinder block with 6-bolt main caps and larger cylinder heads to contain the complex VTEC mechanism. Innovative connecting rods made from a titanium alloy were used to lower reciprocating weight, while increasing overall rod-strength—something which increased the engine's maximum rpm by 700, resulting in a final redline of 8,000 rpm. A consequence of this last-minute engine change was that the new C30A engine was too large to fit in the NS-X's engine bay, which had been carefully sized for the smaller heads of the non-VTEC DOHC 3.0 liter engine. As a result, the engineers were forced to tilt the entire engine backward approximately 5 degrees- a characteristic that continued all the way to the NSX's final production in 2005.

The exterior design had been specifically researched by Uehara after studying the 360-degree visibility inside an F-16 fighter jet's cockpit. Thematically, the F-16 came into play in the exterior design as well as establishing the conceptual goals of the NSX. In the F-16 and other high performance air-crafts such as unlimited hydroplanes along with open-wheel race cars, the cockpit is located far forward and in front of the power plant. This "cab-forward" layout was chosen to optimize visibility while the long tail design enhanced high speed directional stability. The NSX was designed to showcase several automotive technologies, many derived from Honda's F1 motor-sports program.

The NSX was the first production car to feature an all-aluminium semi-monocoque, incorporating a revolutionary extruded aluminium alloy frame and suspension components. The use of aluminium saved nearly 200 kg (441 lb) of weight over the use of steel in the body alone, while the aluminium suspension arms saved an additional 20 kg (44 lb); a suspension compliance pivot helped maintain wheel alignment changes at a near zero value throughout the suspension cycle. Other notable features included an independent, 4-channel anti-lock brake system; an electric power steering system; Honda's proprietary VTEC variable valve timing system and in 1995, the first electronic throttle control fitted in Honda production car.

With a robust motorsports division, Honda had significant development resources at its disposal and made extensive use of them. Respected Japanese Formula One driver Satoru Nakajima, for example, was involved with Honda in the NSX's early on-track development at Suzuka race circuit, where he performed many endurance distance duties related to chassis tuning. Brazilian Formula One World Champion Ayrton Senna, who won many races in Formula One with Honda before his death in 1994, was considered Honda's main innovator in convincing the company to stiffen the NSX's chassis further after initially testing the car at Honda's Suzuka GP circuit in Japan. Senna further helped refine the original NSX's suspension tuning and handling by spending a whole day test driving prototypes and reporting his findings to Honda engineers after each of the day's five testing sessions. Senna also tested the NSX at the Nürburgring and other race tracks. As a result of Senna's input, Honda took the NS-X prototype to the Nurburgring to tune the chassis stiffness. Over the course of several months, the chassis was refined in a painstaking process: Nakajima would drive a lap on the circuit and then discuss with the Honda engineers where he felt flex in the chassis. The engineers would hand-weld aluminum braces in the area they believed would fix the issue and send the driver back out to confirm. This process was repeated over and over, with the data results sent directly to Honda headquarters in Japan, where it was fed into a Cray supercomputer and translated into reinforcements in the production aluminum monocoque. As a result of this process, the NS-X chassis stiffness increased by over 50% with only a small increase in weight. The suspension development program was similarly far-ranging and took place at the Tochigi Proving Grounds, the Suzuka circuit, the 179-turn Nürburgring Course in Germany, HPCC, and Honda's newest test track in Takasu, Hokkaido. Honda automobile dealer Bobby Rahal (two-time CART PPG Cup and 1986 Indianapolis 500 champion) also participated in the car's development.

Official launch and production[]

The NSX made its first public appearances in 1989, at the Chicago Auto Show in February and at the Tokyo Motor Show in October of that year, receiving positive reviews. Honda revised the car's name from NS-X to NSX before commencement of production and sales. The NSX went on sale in Japan in 1990 at Honda Verno dealership sales channels, supplanting the Prelude as the flagship model. The NSX was sold under Honda's Acura luxury brand starting in November 1990 in North America and Hong Kong.

Upon its official debut, the NSX design concept showcased Honda's technology, measuring only 1,170 mm (46 in) in height, making it only 141.3 mm (5.56 in) taller than the Ford GT40, a GT racing car designed and funded solely to win at LeMans. The Japanese car maker's race track innovations and competitive history were further exemplified on the road by the NSX's ultra-rigid and ultra-light all aluminium monocoque chassis along with front and rear double wishbone suspension, with forged control arms connected to forged alloy wheels. The car additionally boasted the world's first production car engine with titanium connecting rods, forged pistons, and ultra high-revving capabilities – the redline was at 8,300 rpm – all traits usually associated with track and race engineered cars. The NSX's exterior had a dedicated 23-step paint process, including an aircraft type chromate coating designed for chemically protecting the aluminium bodywork and a waterborne paint for the base coat to achieve a clearer, more vivid top color and a smoother surface finish.

The car's chassis rigidity and cornering/handling capabilities were the results of Formula One driver Ayrton Senna's consultation with NSX's chief engineers while testing the NSX prototype at Honda's Suzuka Circuit during its final development. The NSX was initially assembled at the purpose-built Takanezawa R&D Plant in Tochigi from 1989 to early 2004, when it was moved to Suzuka Plant for the remainder of its production life. The cars were assembled by approximately 200 of Honda's highest-skilled and most experienced personnel, a team of hand-picked staff with a minimum of ten years assembly experience employed from various other Honda facilities to run the NSX operation.

Production of the first generation of the NSX ended on November 30, 2005. Sales in the United States and Canada ended in 2005 and 2000, respectively.

As of the end of June 2005, the NSX achieved total worldwide sales of more than 18,000 units in over 15 years.

Variants[]

NSX-R (1992)[]

While the NSX always was intended to be a world-class sports car, engineers had made some compromises in order to strike a suitable balance between raw performance and daily driveability. For those NSX customers seeking a no-compromise racing experience, Honda decided in 1992 to produce a version of the NSX specifically modified for superior track performance at the expense of customary creature comforts. Thus, the NSX Type R (or NSX-R) was born. Honda chose to use its moniker of Type R to designate the NSX-R's race-oriented capabilities.

Honda engineers started with a base NSX coupé and embarked on an aggressive program of weight reduction. Sound deadening, the audio system, spare tyre, air conditioning system and traction control along with some of the electrical equipment were removed. The power leather seats were replaced with lightweight carbon-kevlar racing seats made by Recaro for Honda. However, electric windows and fore/aft electric seat adjusters were retained. The stock forged alloy wheels were replaced with lighter forged aluminium wheels produced by Enkei, which reduced the car's unsprung weight. The standard leather shift knob was replaced with a sculpted titanium piece. Overall, Honda managed to reduce approximately 120 kg (265 lb) of weight as compared to the standard NSX, resulting in the NSX-R's final weight of 1,230 kg (2,712 lb).

As found by the automotive press such as Car and Driver in their September 1997 issue's comparison of "Best Handling Car for more than $30K", the NSX, due to its mid-engine layout and rear-end link travel, was susceptible to a sudden oversteer condition during certain cornering maneuvers. While this condition rarely occurred during normal driving conditions, it was much more prevalent on race tracks where speeds were much higher. To address the problem and improve the NSX-R's cornering stability at the limit, Honda added one aluminium bracket under the front battery tray and added one bracket in front of the front radiator to add more chassis rigidity replacing the entire suspension system with a more track oriented unit, featuring a stiffer front sway bar, stiffer suspension bushings, stiffer coil springs and stiffer dampers.

The standard NSX has a somewhat rearward bias in its spring and bar rates, where the rear was relatively quite stiff versus the front. This means that the lateral load transfer distribution, or the amount of load that is transferred across the front axle versus the rear while cornering, is rather rear biased. This can make the car quite lively and easy to rotate at low speed, but during high speed cornering, this effect becomes more pronounced and could be a handful to manage. To reduce the tendency to oversteer, Honda fitted softer rear tyres on the NSX. For the NSX-R, Honda reversed the spring bias, placing stiffer springs on the front suspension along with stiffer front sway bar. This shifted the load transfer stiffness balance farther forward, resulting in more rear grip at the expense of front grip; this had the effect of decreasing the oversteer tendency of the car, making it much more stable while cornering at high speeds. Overall, the NSX-R utilises a much stiffer front sway bar along with stiffer springs than the standard NSX (21.0 mm x 2.6 mm front sway bar: front 3.0 kg/mm, rear 4.0 kg/mm for the NSX versus front 8.0 kg/mm, rear 5.7 kg/mm for the NSX-R).

Honda also increased the final drive ratio to a 4.235:1 in place of the 4.06:1, which resulted in faster gear changes. This change improved acceleration at the expense of top speed, and a higher locking limited-slip differential was installed. Also, the NSX-R's 3.0-litre engine had a blueprinted and balanced crankshaft assembly which is exactly the same labour-intensive high precision process done for Honda racing car engines built by highly qualified engine technicians.

Beginning in late November 1992, Honda produced a limited number of 483 NSX-R variants exclusively for the Japanese domestic market (JDM). Factory optional equipment such as air conditioning, Bose stereo system, carbon fibre interior trim on the centre console as well as the doors and larger wheels painted in Championship White (16-inches at the front and 17-inches at the rear) were available for a hefty premium. Production of the NSX-R ended in September, 1995.

NSX-T (1995)[]

Beginning in 1995, the NSX-T with a removable targa top in black colour was introduced in Japan as a special order option and in North America in March 1995. The NSX-T largely replaced the standard coupé entirely in North America as the only version available post 1994 and all NSXs thereafter were available in targa bodystyle, with two notable exceptions: the Zanardi Special Edition NSX in 1999; and a handful of special order post-1997/pre-2002 3.2-litre base model cars- both of which retained the original hardtop configuration. The European market continued to offer both body styles. The removable roof resulted in decreased chassis rigidity and Honda added about 100 pounds (45 kg) of structural reinforcements to compensate, including significantly thicker frame sidesill rocker panels (the body component which contributes most to the chassis's rigidity), bulkheads, roof pillars and the addition of new front/rear bulkhead and floorpan crossmembers. The targa models, manufactured for the rest of the NSX's production run through 2005, sacrificed weight and some of the original coupé's chassis rigidity in return for an open cockpit driving experience. In addition to this major change, all subsequent NSX-Ts (1995–2001) had smaller-diameter front sway bars, slightly stiffer front springs, softer rear springs and firmer shock-dampers to improve ride comfort and tyre wear while reducing the tendency towards oversteer common in mid-engined vehicles. The small handful of special ordered, base model "hardtop" NSX's from 1997–2001, still retained the original black roof. All other roofs post 1995 were now body-coloured instead of black, although in Japan, the two-tone black roof/body colour was still available as an optional feature. A lighter version of the variable ratio electric assisted power steering rack, previously found exclusively in the cars equipped with the automatic transmission, became standard on all models. Starting in 1995, the 5-speed transmission's second gear ratio was lowered by 4.2% to improve driveability and provide better response and automatic transmissions received an optional Formula One-inspired Sport Shift with a unique steering column mounted electronic shifter. Manual transmission cars received an improved Torque Reactive limited-slip differential – when combined with a new Throttle-By-Wire system, increased corner exit speeds by 10%. Other innovations beginning in 1995 included a new and lighter exhaust system and muffler configuration for greater efficiency and lower emissions, an OBD-II onboard diagnostic system, improvements in the Traction Control System (TCS) and newly developed fuel injectors.