Overview of the 1995 Acura NSX/NSX-T
When Acura envisioned the NSX, the goal was ambitious: to craft a hand-built, mid-engine exotic sports car that would redefine benchmarks for prestige, performance, refinement, driveability, and reliability. The Acura NSX was not just intended to join the exotic sports car category; it aimed to establish a new paradigm altogether.
For the 1995 model year, Acura broadened the NSX’s appeal with the introduction of the NSX-T. This iteration offered an exhilarating open-top driving experience thanks to its removable roof panel. The NSX-T was designed to amplify the excitement associated with the NSX while upholding the coupe’s exceptional performance and sophisticated engineering.
Developing the NSX-T was a complex undertaking that went beyond simply removing the roof. Acura engineers meticulously reinforced critical body areas to ensure the open-top model retained the handling precision and structural rigidity synonymous with the NSX coupe. Reinforcements were strategically implemented in the rocker panels, front and rear bulkheads, floorpan, and other key structural points.
The 1995 NSX lineup also benefited from several technical enhancements and refinements applicable to both the coupe and NSX-T. Notably, the optional Formula One-inspired Sport Shift automatic transmission debuted, featuring an innovative column-mounted electronic shifter. This system allowed drivers to manually change gears without taking their hands off the steering wheel, enhancing both driving engagement and safety by maintaining focus on the road.
Further innovations for 1995 included a drive-by-wire throttle system, a redesigned exhaust and muffler configuration for improved efficiency and reduced emissions, an OBD-II onboard diagnostic system, enhanced Traction Control System (TCS), and newly engineered fuel injectors. The drive-by-wire system also enabled a lower activation threshold for the Traction Control System, further improving stability and driver control. Additionally, all 1995 NSX models came standard with variable electric power-assisted steering, a system initially introduced on automatic transmission-equipped NSXs.
Importantly, all 1995 NSX models were engineered to meet the stringent 1997 federal side impact safety standards, underscoring Acura’s commitment to safety alongside performance.
Concepts and Goals Behind the NSX Sports Car
The original NSX design was guided by a clear set of objectives:
- Benchmark Performance: Achieve performance metrics that equaled or surpassed existing exotic sports cars.
- Everyday Liveability: Ensure the NSX was as user-friendly and practical as any other Acura vehicle.
- Exceptional Handling: Deliver class-leading handling and responsiveness.
- Comfort and Ergonomics: Offer a high degree of comfort, ergonomic interior design, and minimize cabin noise.
- Unwavering Reliability and Durability: Match the reliability and durability standards of mass-produced automobiles.
- Lightweight Construction: Utilize lightweight materials throughout the vehicle’s construction.
- Premium Fit, Finish, and Materials: Achieve an exceptionally high level of fit, finish, and material quality.
- Exclusive Production: Maintain limited production volumes to enhance exclusivity.
- Superior Climate Control: Equip with a climate control system capable of maintaining comfort in all weather conditions.
The Acura NSX successfully met these initial goals, establishing itself as a formidable competitor in the exotic sports car market. For the NSX-T, the objectives expanded to include the thrill of open-air driving while maintaining the original NSX’s core attributes. Key priorities for the NSX-T were:
- Preserving Body Rigidity: Maintain exceptional body rigidity to ensure excellent handling and driving precision.
- Maintaining Noise Insulation: Uphold the original NSX’s levels of noise insulation even with the removable top.
- Convenient Roof Panel Storage: Provide a practical and secure storage solution for the removable roof panel.
- Minimizing Wind Buffeting: Reduce wind buffeting at high speeds when driving with the top removed.
- Comprehensive Security System: Ensure the vehicle security system remained fully functional even with the roof panel removed.
General Overview of the NSX Platform
The mid-engine, two-seater Acura Nsx Sports car is propelled by an all-aluminum 3.0-liter V-6 engine, producing 270 horsepower and 210 lb-ft of torque. This naturally aspirated engine features dual overhead camshafts, four valves per cylinder, Acura’s revolutionary Variable Valve Timing and Lift Electronic Control (VTEC) system, and a Variable Volume Induction System. It also incorporates Programmed Fuel Injection (PGM-FI) and a direct ignition system, utilizing individual coils for each spark plug. A five-speed manual transaxle is standard, with the option of an electronically controlled four-speed automatic transmission featuring the Formula One-inspired SportShift mode.
The NSX chassis is constructed entirely from aluminum, contributing to its lightweight nature. The four-wheel independent double-wishbone suspension system also uses aluminum-alloy control arms and hub carriers at both the front and rear, along with aluminum subframes for mounting. The braking system consists of ventilated four-wheel disc brakes and an advanced four-channel Anti-Lock Braking System (ABS). A sophisticated Traction Control System (TCS) is designed to minimize wheelspin, enhancing control on slippery surfaces.
With the 1995 models, the Acura NSX was available in both hardtop coupe and removable top NSX-T configurations. Both versions were engineered to comply with the 1997 federal side impact standards, reinforcing Acura’s commitment to safety and performance.
1995 Acura NSX/NSX-T Powertrain: Engineering Excellence
Powertrain Overview
The heart of the Acura NSX sports is its all-aluminum, 90-degree, 3.0-liter (2977cc), DOHC, 24-valve V-6 engine. This engine delivers 270 hp at 7100 rpm when paired with the manual transmission and 252 hp at 6600 rpm with the automatic transmission. Both configurations produce 210 lb-ft of torque at 5300 rpm. The manual transmission variant boasts an 8000 rpm redline, while the automatic version has a 7500 rpm redline.
A key technological highlight is the electronically controlled Variable Valve Timing and Lift Electronic Control (VTEC) system. VTEC optimizes engine performance across the rev range by adjusting valve timing and lift, overcoming the traditional trade-off between low-end torque and high-end power. Complementing VTEC, the Variable Volume Induction System dynamically alters the intake system configuration based on engine speed. This system works in conjunction with VTEC to broaden the torque curve and boost peak power.
Advanced Engine Components
The NSX engine block is constructed from aluminum alloy with cast-in iron cylinder liners, balancing lightweight design with durability. The crankshaft is a robust, fully counterweighted forged steel unit. The cylinder heads are made from low-pressure cast aluminum, featuring a pent-roof combustion chamber design with a generous squish area to promote efficient combustion. Centrally located platinum-tipped spark plugs ensure optimal flame propagation and extended service life.
A standout feature of the NSX engine is the use of titanium connecting rods. Acura was the first to incorporate titanium connecting rods in a production car, a technology typically reserved for Formula One and racing engines. These titanium rods are significantly lighter and stronger than steel counterparts, reducing weight by 190 grams per rod.
VTEC and Variable Volume Induction System in Detail
The Variable Valve Timing and Lift Electronic Control (VTEC) system is central to the NSX’s engine performance. It ingeniously resolves the compromise between low-speed torque and high-speed horsepower through a unique camshaft and rocker arm design. Each cylinder’s pair of intake or exhaust valves has three rocker arms and corresponding camshaft lobes. The outer lobes are designed for low- to mid-rpm operation, while the center lobe features a more aggressive profile optimized for high-rpm power.
Below 5800 rpm, the valves are actuated by the outer lobes. Above this threshold, the VTEC computer activates a spool valve, directing engine oil to pistons in the rocker arms. This oil pressure locks the three rocker arms together, forcing them to follow the high-lift center cam lobe, thus enhancing high-end performance. The transition between low- and high-lift modes occurs in a mere 0.1 seconds, imperceptible to the driver.
Complementing VTEC, the Variable Volume Induction System further optimizes engine performance. It utilizes a secondary intake air plenum located beneath the main intake manifold, separated by six butterfly valves. These valves open between 4600 and 4900 rpm, actuated by manifold vacuum. The increased volume from the secondary plenum creates a sonic pressure wave, enhancing cylinder filling just as the intake valves open, boosting both low-end torque and high-rpm power.
Fuel Injection, Diagnostics, and Exhaust
The Programmed Fuel Injection (PGM-FI) system ensures precise fuel delivery to each cylinder, tailored to varying load and speed conditions. For 1995, a new air-assist mechanism was introduced to improve fuel atomization at lower temperatures, enhancing combustion efficiency.
The 1995 NSX also features an advanced Onboard Diagnostic System (OBD-II). This system records and stores data on intermittent engine malfunctions, accessible via a diagnostic port to facilitate maintenance and repairs.
The exhaust system was redesigned for the 1995 NSX, becoming lighter and more efficient. Larger catalytic converters, now 1.14 liters compared to 0.96 liters, were relocated closer to the engine for quicker light-off and reduced emissions without compromising power. Spherical joints replaced conventional flexible tubes, further reducing weight. The exhaust tip was also updated to a circular shape from oval.
Direct Ignition and Transmission Systems
The Direct Ignition System, featuring a coil mounted directly atop each spark plug, ensures a strong, stable spark at high rpm, mirroring Formula One engine technology.
The standard manual transmission is engineered for durability, offering short shift throws and precise, quick response—among the shortest in the exotic sports car segment. A dual-cone synchronizer for second gear and synchromesh for reverse gear enhance shift smoothness and speed. For 1995, the second gear ratio was revised to 1.800:1 from 1.727:1, a 4.2% reduction, improving driveability and responsiveness.
To manage the NSX engine’s high torque and power, a twin-disc clutch was developed. This design increases torque capacity while maintaining a light clutch feel and reducing rotating inertia for quicker throttle response.
SportShift Automatic Transmission Innovation
The optional SportShift four-speed automatic transmission offers drivers a dual-mode experience: conventional automatic shifting or manual gear selection via fingertip controls on the steering column. Inspired by Formula One transmissions, this system allows manual gear changes without removing hands from the steering wheel, boosting both driver engagement and safety.
The shift quadrant (PRNDM21) is displayed on the tachometer. SportShift mode is engaged by selecting ‘M’ (Manual). In manual mode, gear position is indicated in a window next to the quadrant. Upshifts are made by moving the fingertip lever up, and downshifts by moving it down. A CPU circuit prevents engine over-revving during downshifts.
The automatic transmission includes a programmed lockup torque converter to improve fuel economy and reduce slippage, active in second, third, and fourth gears in SportShift manual mode during acceleration and deceleration.
Advanced Differential Technologies
A new torque reactive limited-slip differential was developed for manual transmission NSX models to minimize inner wheelspin. It uses a multi-plate clutch and helical-type planetary gears. In straight-line driving, a spring-loaded disc controls slip. In corners, the helical gears override the spring, preventing inner wheelspin and enhancing stability, improving corner exit acceleration by up to 10% in tests.
Automatic transmission NSX models feature a torque control differential employing a multi-plate clutch and planetary gearset to enhance stability in crosswinds and on split-friction surfaces. It detects and counteracts rotational differences between rear wheels, transferring torque to the slower wheel to maintain vehicle trajectory.
Traction Control and Drive-By-Wire Throttle
The Traction Control System (TCS) is designed to minimize rear wheelspin on slippery surfaces, engineered as a high-performance system rather than a low-speed traction aid. Utilizing ABS wheel-speed sensors and a G-sensor, TCS detects potential wheelspin and reduces engine air and/or fuel delivery. Drivers can disengage TCS via an instrument panel switch. Refinements for 1995 increased sensitivity and lowered the activation threshold, engaging TCS preemptively using wheel-speed sensors and the new drive-by-wire throttle system. New logic also enhances stability during sudden deceleration on slippery surfaces.
The drive-by-wire throttle system, new for 1995, replaces the traditional cable with an all-electronic system. Pedal position is sensed and relayed to a computer, which instantaneously activates the throttle. This system uses a throttle pedal sensor, throttle angle sensor, electronic control unit, and a step motor for throttle control, enhancing cruise control precision and overall electronic system efficiency and reliability.
1995 Acura NSX/NSX-T Interior and Body: A Cockpit of Innovation
Body Structure and Reinforcements
A high-rigidity structure is crucial for a performance car, providing a stable platform for suspension geometry and minimizing interior rattles. Lightweight construction enhances the power-to-weight ratio, improving performance with less horsepower. Acura chose aluminum for the NSX’s body to meet rigidity and weight targets.
Using a Cray supercomputer and Finite Element Modeling (FEM), engineers developed a chassis weighing just 210 kg (462 lbs) with doors, hood, and decklids—40% lighter than steel, yet with comparable rigidity and superior stiffness to competitors.
For the 1995 NSX-T, extensive body reinforcements were added to compensate for the removable roof. These included redesigned, thicker-walled side sill aluminum extrusions, reinforced B-pillar bases, a larger rear bulkhead crossbar, thicker trunk leading edge panel, reinforced rear floor cross member, additional rib in the rear bulkhead, redesigned roof rail sections, thicker A-pillars, a redesigned dashboard cross-member, and a reinforced front lower floor section.
Removable Top and Aluminum Construction
The NSX-T’s removable top is made of lightweight aluminum, body-colored, and easily removed via two latches. At just 8.5 kg, it’s easy to handle and store. A dash light alerts if latches aren’t secured. The panel stores under the rear glass hatch, which can be locked for security. This storage is independent of trunk or interior space, and the security system remains active with the top removed.
Extruded aluminum side sills are critical for the NSX’s high torsional stiffness. For the NSX-T, these were significantly reinforced with increased wall thicknesses in key sections of the five-sided extrusion.
Radiused front frame rails enhance occupant protection by dissipating collision energy, spreading loads, and diverting them under the passenger cell.
Interior Design Concept and Features
The interior design aimed to emulate a jet fighter cockpit, emphasizing visibility, snugness, and a sense of connection to the driving environment. Seating is designed to be snug at the hips, widening upwards for head and shoulder space.
A low seating position lowers the center of gravity and improves aerodynamics. A low cowl section allows for a lower dash and instrument panel, enhancing forward visibility and preventing a claustrophobic feel.
Instrumentation is simple and functional, with traditional analog gauges featuring white numerals on a black background. The tachometer and speedometer dominate the instrument panel, flanked by smaller gauges for water temperature, oil pressure, fuel, and voltage. Major controls are clustered around the steering wheel for easy access.
The NSX-T includes unique features like a dash light for roof panel latch status and a locking mechanism for the roof panel storage compartment.
Safety and Comfort Systems
The NSX features a windshield header designed to direct airflow over the cabin, minimizing wind buffeting, complemented by smaller sun visors for enhanced visibility.
A Dual Air Bag Supplemental Restraint System (SRS) with automatic seat belt tensioners is standard. The tensioners activate with the airbags in severe frontal collisions to enhance occupant restraint.
Leather-trimmed upholstery, hand-stitched and fitted, covers seats, door inserts, steering wheel, and shift knob, available in black or tan regardless of exterior color.
An automatic climate control system, compact yet effective, allows for fully automatic or manual operation.
The Acura/Bose® Music System, a four-speaker system co-engineered with Bose®, is calibrated for the NSX’s acoustics, providing high-quality sound imaging. Speakers are precisely aimed for balanced sound for both occupants. The AM/FM stereo/cassette includes Dolby® Noise Reduction and an FM diversity antenna, with an auto-preset function and optional CD changer.
A sophisticated theft-deterrent system is standard, activating horn, flashers, and starter disablement upon unauthorized entry attempts. It arms automatically 15 seconds after locking and disarms with the key, functioning even with the top removed on the NSX-T.
Manufacturing Excellence and Paint Process
The NSX assembly plant in Tochigi, Japan, is designed for ultimate quality. Cars are moved manually on dollies between workstations, with each team responsible for quality at their station, ensuring high tolerances and specifications are met before moving to the next stage. Engine assembly is performed entirely by individual, highly skilled technicians from start to finish, ensuring precision and reliability.
The NSX undergoes a 23-step paint process, including an aircraft-type chromate coating for aluminum and a waterborne base coat for vivid color and smooth finish.
1995 Acura NSX/NSX-T Chassis: Precision Handling and Control
Advanced Suspension System
The NSX suspension was designed for more than just lateral grip and responsiveness; it aimed to provide drivers with control right up to the car’s limits. It uses a Formula One-style double-wishbone design with coil-over shock absorbers and stabilizer bars front and rear. The rear suspension adds a transverse link for enhanced wheel control. All suspension arms are forged aluminum, with heat-treated aluminum front steering knuckles and rear hub carriers. Straight-rate springs with progressive rubber bump stops at wheel travel limits are used.
Nitrogen-filled shock absorbers feature a progressive valve design for more precise damping control compared to conventional systems.
Suspension components are mounted to aluminum subframes via rubber bushings to reduce vibration while limiting flex.
Extensive suspension development took place at various tracks, including Tochigi Proving Grounds, Suzuka, Nürburgring, HPCC, and Honda’s Takasu test track, with evaluations by drivers like Ayrton Senna, Bobby Rahal, and Satoru Nakajima.
High-Performance Braking System
The NSX features four-wheel ventilated disc brakes with dual-piston steel calipers and 282 mm (11.1-inch) diameter discs front and rear. Braking targets included setting new standards for performance and fade resistance, with good pedal feel and linear response. For 1995, new splash guards with cutouts were added to improve air ventilation and fade resistance.
The four-channel Anti-Lock Braking System (ABS) independently controls each wheel with a 16-bit microprocessor, allowing fine control, especially on surfaces with split friction coefficients. It features independent parallel hydraulic circuits, ensuring normal braking function even if the ABS hydraulic circuit fails.
Variable Electric Power-Assisted Steering and Wheels
The variable electric power-assisted steering system, an American market first, uses a rack-and-pinion system with an electric motor concentric to the steering rack. It provides assist at lower speeds and functions as direct steering at higher speeds. A speed sensor and steering sensor feed data to the motor. Gold-plated connectors enhance reliability. For 1995, this system became standard on all NSX models.
Forged-aluminum alloy wheels reduce unsprung weight and maximize strength. Rear wheels are 8.5 x 17 inches, and front wheels are 7 x 16 inches.
Performance Tires
Tire development, in collaboration with Yokohama and Bridgestone, focused on excellent traction and handling while providing drivers with feedback on tire performance limits. Uniquely designed tires met high-performance targets.
In 1994, larger, lower aspect ratio tires (215/45 ZR16 front and 245/40 ZR17 rear) were introduced for more responsive handling and increased cornering capability, offering excellent wet and dry traction, high-speed stability, and predictable steering response.
The 1995 Acura NSX and NSX-T represent a high point in automotive engineering, blending exotic sports car performance with Acura’s renowned reliability and innovation. These models solidified the NSX’s legacy as a true icon in the sports car world.
