Jul 19

Jul 19 Guide: The Phantom - a Historical & Technical Appraisal of the Nissan KPGC-110 Skyline 2000 GT-R

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BACKGROUND

In September 1972 Nissan began production of a fourth generation Skyline: the C110.

From a styling perspective, this latest Skyline appeared more Americanised than its predecessor while three body styles were once again offered: a four-door Sedan, a two-door Coupe and a five-door Station Wagon (the latter also available as a van).

Mechanically, the new range borrowed heavily from its C10 predecessor with customers initially offered a choice of single overhead cam petrol engine in 1.6, 1.8 or 2-litre trim.

However, that was not quite the extent of the C110 range as, for a few brief months during early 1973, Nissan also produced a hot GT-R version to replace the four-door PGC-10 (1968-1970) and the two-door KPGC-10 that succeeded it (1970-1972).

As a consequence of an advanced technical specification, stellar performance and absolute domination of the Japanese racing scene, these first two iterations of the fabled GT-R had done wonders for Nissan’s domestic image, despite relatively modest production runs.

Indeed, barely 2000 examples of the GT-R had been produced between 1968 and 1972, but the impact these heavily uprated homologation specials had at home was arguably as significant as the 240Z’s international impact; a record of 50 consecutive wins for the PGC-10 and KPGC-10 meant Nissan was legitimately able to position itself as Japan’s premier manufacturer of high performance road-going machinery which helped sprinkle a little stardust on the rest of the company’s range.

The third instalment of the GT-R theme, the KPGC-110, was unveiled at the Tokyo Motor Show in October 1972 where it received a positive reception. In addition to its brand new look (enhanced with brawny over fenders and a custom aero kit), perhaps the most significant technical advancement over prior examples was the addition of disc brakes all round (previous GTRs had run drum-type units at the rear).

Initially, Nissan was optimistic the KPGC-110 (available exclusively in Coupe trim) would continue where its predecessors had left off in terms of both sales and racing success. However, things soon took a turn for the worse and any such plans were quickly abandoned despite the new machine having the same technical merits as its esteemed forebears.

CHASSIS

Each of these latest GT-Rs started life as a standard steel two-door C110 monocoque bodyshell. In typical fashion, this fourth generation Skyline was a little larger than earlier versions in every respect. The wheelbase was extended by 40mm (from 2570mm to 2610mm).

Fully independent suspension was via MacPherson struts up front and semi-trailing arms at the rear. Compared to other models in the C110 range (and like its predecessors), the GT-R came with an array of special equipment to include shorter and stiffer springs, firmer dampers and an anti-roll bar at either end. With its lower ride height and stiffer set-up, handling was much-improved.

Disc brakes were now fitted all round.

Black-painted 14 x 6-inch steel wheels were fitted without hub caps to save weight.

Compared to the outgoing GT-R, track on this latest variant was 20mm wider up front and 10mm wider at the rear.

Instead of the long-rang 100-litre fuel tank fitted over the rear axle on earlier GT-Rs, the KPGC-110 is understood to have adopted a 55-litre item from the regular C110 range.

ENGINE / TRANSMISSION

The KPGC-110’s S20 engine was identical to those units found in the PGC-10 and KPGC-10 versions that came before and thus derived from the Prince GR-8 unit conceived for the R380 Group 6 Prototype.

The S20 motor incorporated a cast-iron block and a trick light alloy cross-flow head with four valves per cylinder, dual overhead camshafts and pent-roof combustion chambers. Each head was meticulously hand ported and polished prior to installation. Tube headers and a free flow dual-pipe exhaust were also fitted.

Fuel feed was via three Mikuni-Solex 40 PHH-3 twin choke sidedraught carburettors and the compression ratio was set at 9.5:1.

Compared to GR-8 race engine, stroke was reduced from 63mm to 62.8mm. The cylinder bores were kept at 82mm for an overall displacement of 1989cc.

Each engine tipped the scales at 199kg.

Peak output was 160bhp at 7000rpm and 130lb-ft at 5600rpm.

Transmission was through a five-speed manual gearbox with dry single-plate clutch and limited-slip differential.

BODYWORK

Whereas the standard fourth generation Skyline Coupe looked somewhat under-wheeled, particularly at the back where chunkier bodywork gave the car a heavier, more substantial profile, a series of exclusive GT-R upgrades transformed its appearance to that of a better balanced baby muscle car.

Compared to the otherwise range-topping 2000 GT-X Coupe, the GT-R featured a simplified nose aperture treatment with a basic mesh grille inboard of the headlights, black instead of chrome fender-mounted exterior mirrors, GT-R badges mounted on the nose and tail and an R-badged dummy fuel filler cap on the right-hand sail panel. Also present were riveted satin black over fenders as introduced on the outgoing KPGC-10 and a full width flush-fitting body colour rear spoiler.

Dimensionally, this latest GT-R was 30mm longer, 30mm wider and 10mm taller than the KPGC-10 that came before.

Body panels were fashioned from steel with plastic resin used for the mirror casings, over fenders and rear spoiler.

INTERIOR

Inside, every aspect of the fourth generation Skyline had been completely redesigned.

All the instrumentation was now housed side-by-side in a seven-gauge hooded binnacle. Unique to the GT-R was a custom 10,000rpm rev counter and 240kph speedometer. The five smaller read outs located alongside (water and oil temperature, oil pressure, fuel and the clock) were imported from the regular Skyline.

Also carried over was the GT’s three twin-spoke leather rimmed steering wheel albeit with red instead of black-backed ‘S’ insignia horn push. A matching red-backed badge was also added to the wooden gear knob. The normally wooden instrument binnacle and centre console inserts found on the regular Skyline were switched to natural aluminium for the GT-R.

Arguably the GT-R’s most special feature was its fixed-back bucket seats with adjustable headrests.

Aside from the leather trimmed steering wheel rim / gear gaiter and carpeted floors / sidewalls, upholstery was a mix of smooth and wrinkled black vinyl leatherette.

OPTIONS

Optional extras were limited to air-conditioning, an audio system and a handsome new set of rarely seen alloy disc wheels.

WEIGHT / PERFORMANCE

At 1145kg the KPGC-110 weighed in 45kg heavier than its predecessor.

As a consequence of its slightly different gearing, Nissan quoted the KPGC-110 with a 0-62mph time of 8.9 seconds (down from 9.6) and a top speed of 119mph (down from 133mph).

END OF PRODUCTION

Within days of the KPGC-110’s launch at the 1972 Tokyo Motor Show, Nissan decided to quit top flight motor racing in an official capacity, even though a competition version of the new GT-R had also been displayed alongside its road-going sister. Instead, seeing which way the economic wind was blowing, the company elected to switch focus to anti-pollution technology and improved fuel efficiency.

As a consequence, Nissan management thought there was no longer any point to offering an ultra high performance derivative of the Skyline and, after just four months in production, the KPGC-110 was dropped.

That was the official story anyway.

However, some respected sources believe the KPGC-110 was created solely to use up Nissan’s stock of leftover S20 engines...