Evo Ichiba - a Historical & Technical Appraisal of the Nissan R32 Skyline GT-R Nismo (RA) & Nismo N1 (ZN)
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BACKGROUND
The FIA’s Group A motor sport regulations that Nissan designed the R32 Skyline GT-R to comply with also permitted manufacturers to build batches of Evolution models.
The Evolution rule enabled firms to make competition-inspired upgrades to the base model with the first Evolution permitted as soon as the base model had been homologated. Subsequent Evolutions were then allowed every twelve months thereafter. To qualify, 500 copies of each Evolution variant had to be built (also within a twelve-month period) compared to 5000 units of the original base model.
Prior to the R32 GT-R’s arrival, arguably the most famous Touring Car-derived models to have exploited the Group A Evolution rule were the two models Nissan would have to beat on track: Ford’s Sierra Cosworth RS500 and the BMW E30 M3.
Compared to a standard Sierra Cosworth, the RS500 came with a host of upgrades including a special engine block, bigger turbo, bigger intercooler, uprated oil and cooling systems, a reworked induction system and revised aero pack.
It was a similar story with the M3 which, for the GT-R’s debut season in 1990, would be on its third Evolution. Having started out with a specialised engine block for the Evolution 1, the M3 Evolution 2 ushered in more power, less weight and improved aerodynamics. The M3 Evolution 3 for 1990 (officially dubbed the Sport Evolution) was the most radical yet with a trick enlarged engine, a revised aero kit, wider track and uprated suspension.
Despite its Division 2 status (for cars of between 1601cc and 2500cc), the normally aspirated M3 had thus far punched well above its weight, often beating the Sierra Cosworth RS500 for outright honours despite the turbocharged Ford having run in the same Division 1 over 2500cc class that the Skyline GT-R would contest.
To stand the very best chance of toppling Ford and BMW from the top of the Group A Touring Car scene, Nissan handed development of what effectively became the GT-R Evolution to its in-house motorsport division: Nismo (Nissan Motorsport International Limited).
Production started in December 1989 and the resultant R32 Skyline GT-R Nismo (model code RA) was officially announced in February 1990. As expected, it featured an array of aerodynamic, mechanical, weight reduction and reliability upgrades.
Priced at a 5% premium over a base R32 GT-R, the Nismo (RA) became the ultimate Skyline placed on general sale.
Homologation was approved on March 1st 1990 to coincide with acceptance of the base model into Group A.
BODYWORK
Externally, the Nismo GT-R featured two rectangular intakes cut from the front bumper that fed additional air to the intercooler.
To direct more air to the engine, a body coloured deflector was added to the leading edge of the hood inboard of the headlights.
For extra downforce, a secondary spoiler was mounted on the trailing edge of the trunk lid underneath the standard wing.
The sill section ahead of each rear wheel was extended downwards to improve air flow.
The rear wiper was deleted to save a little weight.
A Nismo decal was applied to the right-hand side of tail fascia and only one body colour was available: KH2 Gun Grey Metallic.
As usual, the hood and front fenders were fashioned from lightweight aluminium. The bumpers, side skirts and rear spoiler were a mix of polypropylene and fibreglass. Everything else was steel.
INTERIOR
Inside, other than deletion of the stereo, air-conditioning and rear wiper control, there were no changes.
Compared to lesser models in the Syline range, the GT-R came with special high-backed sports seats trimmed in dark grey fabric, a leather-rimmed three-spoke steering wheel and matching leather gear knob.
The main instrument binnacle housed large read outs for road and engine speed. To the right were smaller gauges for oil pressure and water temperature. To the left was a small fuel level indicator and a torque split gauge that showed how much power was being sent to the front differential.
A bank of three extra gauges were located on the centre console: an ammeter, oil temperature gauge and boost read out.
Electric windows were fitted as standard.
ENGINE / TRANSMISSION
For the Nismo (RA), the base GT-R’s RB26DETT straight six engine was enhanced with Garrett T04B turbos instead of the regular T03 type.
Nismo sacrificed the faster spool up of the T03’s ceramic turbo wheels for the enhanced reliability offered by the T04B’s steel turbo wheels. Boost pressure was kept at 0.7 bar. Nismo also removed the protective honeycomb mesh to improve airflow to the intercooler.
Otherwise, the wet-sump, dual overhead cam engine was unchanged. It featured a cast-iron block with light alloy four-valve head and displaced 2568cc thanks to a bore and stroke of 86mm and 73.7mm respectively. Compression was kept at 8.5:1 and the base GT-R’s multipoint fuel-injection was carried over.
Once again, output was officially 276bhp at 6800rpm with 260lb-ft at 4400rpm.
However, to avoid a horsepower war, Japanese manufacturers had a gentleman’s agreement that limited engines to 276bhp. The R32 GT-R’s true horsepower rating was actually 313bhp at 6800rpm.
Transmission was via the existing ATTESSA E-TS permanent four-wheel drive system, a five-speed manual gearbox, multi-plate hydraulic clutch and limited-slip differential.
Nissan developed the ATTESSA E-TS torque-sensitive electronic four-wheel drive system specially for the R32 GT-R. An acronym for Advanced Total Traction Engineering System for All Terrain – Electronic, the ATTESSA E-TS system used a microprocessor to sense lateral G, throttle opening and engine speed. Upon sensing oversteer or broken traction at the rear, it sent torque the rear wheels couldn’t handle up to the front axle. This data was also fed to the anti-lock brake system (ABS) which measured wheel speed and longitudinal G force.
CHASSIS
As ABS was banned in Group A, the GT-R’s anti-lock brake system was deleted from the Nismo version. To compensate, cross-drilled brake discs were installed.
These had the same 297mm diameter at the front and 296mm diameter at the rear as the standard model. Four and two-piston calipers were used front to rear respectively.
As before, the E-BNR32 unitary steel chassis came with independent suspension via double wishbones at the front and a multi-link arrangement at the rear. Coil spring / damper units were installed all round along with anti-roll bars at either end.
Torque-sensitive electronic four-wheel drive used a microprocessor to sense lateral G, throttle opening and engine speed. When the car oversteered or broke traction at the rear, excess torque was sent to the front axle.
Four-wheel steering allowed the rear wheels to turn a maximum of one degree which improved agility and stability. The rear wheels could turn in either the same or opposite direction to the fronts which also assisted low speed manoeuvrability.
The standard 8 x 16-inch five spoke alloy wheels came shod with Bridgestone Potenza tyres.
A 72-litre fuel tank was fitted in the boot floor.
OPTIONS
Options included a Nismo-branded 260kmh speedometer, three-inch cat-back exhaust system, a front suspension strut brace, sports shock absorbers, 17-inch alloy wheels and a rear spoiler with built-in third brake light. A stereo could be re-instated.
WEIGHT / PERFORMANCE
Overall, the Nismo GT-R weighed 1400kg which was 30kg less than the standard GT-R.
Performance figures were officially unchanged. Top speed remained limited to 112mph (180kph) or 165mph once derestricted. 0-62mph took 5.6 seconds.
PRODUCTION
500 copies of the GT-R Nismo (RA) vwere built between December 1989 and March 1990, all of which were right-hand drive and sold into the Japanese Domestic Market.
An additional 60 examples were manufactured that Nissan held back for competition use.
R32 SKYLINE GT-R NISMO N1 (ZN)
In July 1991, Nissan introduced an N1 version of the R32 Skyline GT-R Nismo for Group N racing.
Bearing internal model code ZN, these cars were based on the RA version but featured an array of additional upgrades to include a hand-built and balanced N1 engine with special block and turbochargers, a reinforced brake master cylinder and additional underbody brake cooling ducts.
Lightweight headlights were installed and the trunk carpet was deleted.
To comply with Group N regulations, the brake discs were no longer cross-drilled.
The base Nismo version’s secondary trunk lid spoiler and deep rear skirt were absent in standard trim but could be re-instated at extra cost.
245 copies of the N1 (ZN) R32 GT-R were produced, all of which were painted Crystal White.
Of these 118 were to basic N1 specification.
64 were completed with the V-spec package introduced in January 1993. These cars came with bigger brake discs (324mm front / 300mm rear), a bigger brake master cylinder, uprated Brembo calipers and 17-inch BBS wheels.
63 were completed with the V-spec II package introduced in February 1994 that included everything from the original V-spec pack plus retuned ATTESA E-TS and wider tyres (245/45 R17 instead of 225/45 R17).
COMPETITION HISTORY
Despite having been up against some legendary Group A Touring Cars, the R32 GT-R went on to have a spectacular career. It was in fact so utterly dominant that, within a few years, most championship organisers switched to a new regularity framework in order to make the GT-R obsolete.
Between 1990 and 1993, the GT-R set an unprecedented record that saw it take pole and win every single race in the Japanese Touring Car Championship. The model also won the 1991 and ‘92 Australian Touring Car Championships plus the standalone Bathurst 1000km in 1991 and that year’s Spa 24 Hours.
Text copyright: Supercar Nostalgia
Photo copyright: Nissan - https://www.nissan-global.com
