The cars

The GT6's history can be traced back to 1963 when Giovanni Michelotti was commissioned to design a GT version of their Spitfire 4. Towards the end of 1963 a prototype Spitfire GT was returned to England for evaluation. Although the styling of the vehicle was a success the 1147 cc (70 cu in) Spitfire power unit could not cope with the extra weight of the GT body shell and the resulting performance was poor. In 1964 the Triumph racing-programme produced fiberglass copies of the Spitfire GT's fastback. These were fitted to race-modified Spitfires. The fastback was though to provide aerodynamic benefits over the standard car. The race program was a success culminating in a class win at the 1965 Le Mans 24 Hour race. This success led Triumph to revive the Spitfire GT project and to overcome the lack of performance the 6 cylinder 2 Litre engine that was currently being fitted to the Vitesse was installed in the new fastback car. Although Triumph made good use of the Le Mans success in its marketing for the GT6 - the GT6 was developed entirely separately to the Le Mans Spitfires.

The Cars

 

Triumph GT6 Mark I

Total Production : 15,818

Dates : July 1966 to Sept 1968

Commission Numbers : KC 1 - KC 13,752

Introduced in 1966 the GT6 MK1 was an instant success. The engine for the GT6 was taken from the then current Vitesse. This was a 95bhp straight six 2 litre. In this form the car was capable of 105mph (169kph), with a 0-60 time of 12 seconds. Compared to the Spitfire the trim was more luxurious with walnut dash and fully carpeted cabin. One of the complaints levelled at the car was its lack of ventilation. The Cabin became quite hot from the extra heat produced by the 6 cylinder engine. The motoring press of the time highlighted the GT6's rear suspension as its Achilles heel - whilst adequate for the Herald and Spitfire it was thought inadequate for the more powerful and heavier GT6. Of the options offered for the car overdrive was probably the most popular.

Triumph GT6 Mark 2

Total Production : 12,066

Dates: July 1968 to Dec 1970

Commission Numbers: KC50001-KC58046 and KC75001-KC83397

The bad press relating to the rear suspension forced Triumph into a redesign. The result was a double-jointed half shafts (one traditional UJ and an outer rubber "Rotoflex" coupling) the original transverse leaf spring acting as top wishbones, and new lower wishbone added to keep the rear geometry in check. Engine output was increased to 105bhp by using the better breathing cylinder head of the TR5. This gave the car a top speed of 112mph and a (0-60mph time of 10.1 seconds. American cars were subject to more stringent emission controls which reduced the power of the engine to 95bhp. In the states the car was sold as the GT6+. In common with the Spitfire, the GT6 had it's front bumper raised (more US legislation) and improvement to its interior trim together with a better redesigned ventilation system, making, in my opinion, this the best of all the GT6s. Wire wheels, optional rear seat and overdrive continued to be listed as options.

Triumph GT6 Mark 3

Total Production : 13,042

Dates: Oct 1970 to Dec 1973

Commission Numbers: KE0001-KE04596, KE10001-KE14816, KE20001-KE24218

The Mark 3 shared bodywork design changes with the Spitfire IV which had similar tail design to the Stag. Although the early cars retained the Rotoflex rear suspension by 1973 it was replaced by the spitfires swing spring layout The bonnet t vents went as did some of the raised seams. New American emission laws were introduced and by 1972 the American spec GT6 engine produced a miserly 79bhp. This equated to a top speed of 95mph and a 0-60 time of 12 seconds compared to 112mph with 0-60 in 10.1 for the UK car . As a result US sales dropped and although there was never an official announcement the last GT6 rolled off the production line in late November 1973.