The Triumph GT6 is a 6-cylinder sports coupé built by Standard-Triumph, based on their popular Triumph Spitfire convertible. Production ran from 1966 to 1973.
Development history
In early 1963 Giovanni Michelotti was commissioned by Standard-Triumph to design a GT version of their recently introduced Spitfire 4 (also designed by Michelotti). An unmodified Spitfire 4 was delivered to Michelotti's design studios in Italy and late in 1963 the prototype Spitfire GT4 was returned to England for evaluation. The styling of the vehicle was a success but the extra weight of the GT bodyshell resulted in extremely poor performance from the Spitfire's Standard SC engine, and plans for producing the Spitfire GT4 were shelved.
Michelotti's fastback design for the Spitfire GT4 prototype was adopted by the Triumph racing programme for the 1964 season, as it was deemed to provide an aerodynamic benefit over the standard Spitfire body shape. Fibreglass copies of the Spitfire GT4's fastback were grafted on to the race-modified Spitfires destined for competition. The Spitfire racing programme was successful, and in 1965 resulted in 13th overall and a 1st in class at the prestigious 24 Hours of Le Mans (beating their main rivals, the MG Midgets). The Spitfire's competitive success and the continuing commercial success of the production vehicle led Triumph to re-evaluate its shelved plans for a GT version of the Spitfire. To overcome the lack of performance inherent in the heavier body style the Spitfire's 4-cylinder engine was replaced with the more powerful Triumph inline 6 originally derived from the SC and then in use in the Triumph Vitesse (which shared a similar chassis with the Spitfire and Triumph Herald). The car was further developed and refined and eventually launched as the Triumph GT6 (dropping the "Spitfire" prefix) to emphasise its GT styling and its 6-cylinder engine.
Contemporary Triumph marketing advertised the GT6 as being developed from the "race winning Le Mans Spitfires" to capitalise on their aesthetic similarities, whereas the Le Mans Spitfires and the GT6 were actually two entirely separate development programmes (the GT programme pre-dating the racing programme). However, the marketing spin was so successful that many people erroneously believed the Le Mans Spitfires to actually be GT6s.
Models
The following models were produced during the production run:
Production Total (all models): 40,926
GT6 Mk I
The new car was introduced in 1966 and called the Triumph GT6. The new body was a sleek fastback design with an opening rear hatch, earning the GT6 the nickname of poor man's E-Type. It was really a 2-seater, but a small extra rear seat could be ordered, large enough for small children. The family resemblance to the Spitfire Mk II was strong, the longer 6-cylinder engine necessitated a new bonnet top with a power bulge and the doors were provided with opening quarter light windows and squared-off glass in the top rear corner. The 6-cylinder engine was, like the Vitesse 2 litre, tuned to develop at 5000 rpm, and produced of torque at 3000 rpm. The increased power necessitated certain changes to the Spitfire mechanics; the radiator was new and mounted further forward in the car and the gearbox was the stronger unit from the Vitesse 2 litre, with synchromesh on all 4 forward gears. An optional Laycock de Normanville overdrive was offered giving a 20 per cent overdrive on 3rd and 4th gears. In effect this added only one ratio as overdrive 3rd was identical to 4th without overdrive. The overall gearing of overdrive and non-overdrive cars was not different as the non o/d cars came with a 3.27:1 differential while the overdrive cars' diffs were the same as the Vitesse 2 litre at 3.89:1. Front springs were uprated to cope with the extra weight of the new engine. The overall vehicle weight unladen was . The interior of the GT6 features a wooden dashboard housing a full complement of instruments, with carpets and heater included as standard.