Triumph GT6: the Spitfire that grew a six

The Triumph GT6 was a six-cylinder sports coupé built by Standard-Triumph on the Spitfire chassis. It was made from 1966 to 1973, and its fastback body with a rear hatch earned it the nickname of the poor man’s E-Type.

Triumph GT6 at a glance

Based on the English Wikipedia article on the GT6.

History of the Triumph GT6

1963: a GT Spitfire that was too slow

In early 1963 Standard-Triumph asked Giovanni Michelotti to design a GT version of the Spitfire. An unmodified Spitfire 4 went to his studio in Italy and the prototype Spitfire GT came back to England late that year. The styling worked, but the extra weight of the closed body made the 1147 cc Spitfire engine feel hopelessly slow, and the project was shelved.

The racing connection

Michelotti’s fastback was taken up by the Triumph racing programme for 1964, since it gave an aerodynamic advantage over the open Spitfire. Fibreglass copies of the fastback were fitted to the race cars, and in 1965 a Spitfire finished 13th overall and first in class at Le Mans. That success, and continuing sales of the road car, persuaded Triumph to revive the GT idea. The answer to the weight problem was the 2-litre six from the Vitesse, which shared the Herald and Spitfire chassis family. The car was launched as the Triumph GT6 — the “Spitfire” prefix dropped, the “6” added. Triumph’s marketing linked the GT6 to the Le Mans Spitfires, although the two programmes were entirely separate.

1966: the GT6 Mk I

The GT6 arrived in 1966 with a sleek fastback body and an opening rear hatch. It was really a two-seater, though a small rear seat for children could be ordered. The longer six-cylinder engine required a new bonnet with a power bulge. Tuned like the Vitesse 2 litre, the engine produced 95 hp at 5000 rpm and 159 Nm at 3000 rpm, giving 106 mph and 0–60 mph in just under 12 seconds — a little better than an MGB GT, and with a smoother, more flexible engine. The radiator was new and mounted further forward, the gearbox came from the Vitesse 2 litre with synchromesh on all four gears, and an optional Laycock overdrive gave 20 per cent overdrive on third and fourth. Fuel economy was around 20 mpg.

The handling problem and the Mk II

The one serious criticism was the rear suspension. The GT6 inherited the Spitfire’s swing axles, copied in turn from the Herald, and with the heavier six up front the car could break away if the driver lifted off mid-corner. The criticism was especially loud in the United States, an important export market. For the 1969 model year Triumph introduced the GT6 Mk II, sold in North America as the GT6+, with reversed lower wishbones and Rotoflex driveshaft couplings. That tamed the handling and turned the car into what period writers called an MGB beater. The Vitesse was modified in the same way, and production of the GT6 continued until 1973, by which time 40,926 had been built.

Design and features

• Six-cylinder engine — the 2-litre Vitesse unit, 95 hp and 159 Nm.
• Fastback body — Michelotti styling with an opening rear hatch and a bonnet power bulge.
• Overdrive option — 20 per cent on third and fourth gears.
• Mk II chassis fix — reversed lower wishbones and Rotoflex couplings cured the swing-axle behaviour.

Triumph GT6 versions

• GT6 Mk I (1966–1968): 95 hp, swing-axle rear suspension.
• GT6 Mk II / GT6+ (1969): revised rear suspension, raised front bumper.
• Later Mk III cars: the final development, sold until 1973.

The GT6 shares its chassis family with the Spitfire, Herald and Vitesse. More in the Triumph collection.

Sources

• Triumph GT6, English Wikipedia: development, Mk I specification, Mk II suspension, production total