The Triumph GT6
It was in 1961 that Triumph launched the Triumph Spitfire onto the market as a direct competitor to the Austin–Healey Sprite. With a twin–carburetted 4–cylinder 1147cc engine driving the rear wheels through a 4–speed gearbox (overdrive became an option), the Triumph Spitfire offered affordable open top driving fun. However, it wasn’t a particularly quick sports car, but that didn’t seem to be the point.
In 1963, with sales of the Spitfire holding strong, Triumph looked to increase model variation of its sports cars, to add to the Triumph TR4 and the Spitfire. Italian car designer, Giovanni Michelotti, who had become well established with Triumph, was asked to come up with a hard top coupé variant of the now very popular Triumph Spitfire.
Michelotti had a production Spitfire delivered to him in Turin to work with. A year later, when he had finished, Michelotti sent the car back to Triumph where it was decided the hard top sports coupé should be called the Triumph Spitfire GT.
Unfortunately, Michellotti’s design had added too much weight to the car for the 63bhp 4–cylinder engine to cope with and so the idea of producing it commercially was postponed.
The 2–Litre Six–Cylinder Triumph Engine
In 1964, however, the Triumph Spitfire GT project was resurrected when it was decided to give it a 2–litre, six–cylinder engine. At the same time the Herald derived Triumph Vitesse was being upgraded from a straight–six 1600cc power unit to a developed 2–litre version. This engine was also being fitted to the new Giovanni Michelotti designed Triumph 2000 saloon.
Getting the straight six–cylinder engine into what was the engine bay of a Triumph Spitfire, and with all the ancillary components, required a bit of juggling.
However, by shortening the propeller shaft, moving the gearbox mountings further back, and designing a new cooling system, the engineers managed to do it. The one–piece front of the car, which formed the bonnet, had to be modified with a bulge along its centre, so as to clear the front of the engine rocker cover.
The 2–litre version of the Spitfire GT was branded as the Triumph GT6, with the No.6 denoting the six–cylinder engine, and assembly of the production cars began in July 1966. By 1967, a build rate between five and six hundred cars per month had been achieved.
Triumph GT6 Mk2
In autumn 1968, the Triumph GT6 Mk2 was introduced and this had revised front end styling that matched that of the Triumph Spitfire Mk3.
The Triumph GT6 had been little more than a Spitfire with a 2–litre engine, a hard top coupé body with a bulge in the bonnet. Therefore, it shared the same chassis and same independent suspension design. Consequently, and right from the start, there were customer complaints about the rear wheel tuck–under problems associated with the Triumph swing axle rear suspension system.
To counter this, the Triumph GT6 Mk2 was fitted with an advanced rear suspension layout. This involved a reversed lower wishbone and double–jointed drive shafts. The resulting effect to the handling was most impressive. However, the modification was never made to the Triumph Spitfire, which had to wait for its upgrade in the form of the Mk4, launched in 1970.
The Mk2 GT6 acquired a new cylinder head, borrowed from the Triumph TR5, and together with a revised camshaft profile, power output was increased from 95bhp @ 5000rpm to 104bhp @ 5300rpm. Top speed was listed as 117mph and 0–60 as coming up in 10.1 seconds. By contrast, the rival MGB could manage 105mph with a 0–60 time of 13–seconds.
In early 1970 the Mk2 GT6 was given a trim upgrade, which included new reclining seats, a matt black facia surround, a new steering wheel and new badges.
Triumph GT6 Mk3
In November 1970, the Triumph GT6 Mk3 was launched, incorporating all the body styling features of the Spitfire Mk4. Although the bonnet still retained the bulge along its centre, this has been somewhat flattened out to be less prominent.
The roof line was altered, on account of a taller windscreen, and the door handles and fuel filler were made to fit flush to the body. The rear suspension was again re–worked to include an anti–roll bar, providing even better road manners.
Triumph Sales in North America
Exports to North American car market, this being the largest customer, were vital to the survival of Triumph, but in 1972, US exhaust emission regulations changed. To comply to US specification demands, changes to carburettor, piston, ignition, distributor and camshaft design had to be made, reducing the power output to 95bhp of the GT6.
In 1973, the GT6 Mk3 received a facelift with new fabric upholstery, new style instruments, Sundym glass for the windows, and for the European market, servo assisted brakes.
However, further restrictions on exhaust emissions in the United States required extensive modification to the Triumph engine, reducing power output for US specification cars to just 79bhp. This was little more than that of the UK specification Spitfire.
This cost implications the modifications placed on the car meant it was no longer attractive to buyers, due to the higher price tag. In an effort to build the GT6 more cheaply the rear suspension was changed to that of the swing axle system of the Mk4 Triumph Spitfire, trying and keep it cost–competitive to its nearest rival, the MGB GT.
Required Updates to the Triumph GT6 Would be too Expensive
The reality of the US situation for the GT6 was it could no longer survive and when further North American safety and exhaust emissions legislation came into force, this proved to be the last straw. Modifications necessary to bring the Triumph GT6 up to the standard required would have cost too much, added too much weight to the car and further restricted the power output of the already strangled six–cylinder engine.
The Triumph GT6 never sold in large numbers and as a commodity it was a very much under rated and undervalued car. Whilst the Triumph Spitfire consistently outsold its closest rival, the MG Midget, the GT6 was always severely beaten by its rival, the MGB GT.
Perhaps with better marketing strategy there would have been a greater sales success story written about the Triumph GT6. Not only was it mechanically superior to the MGB, had more style and a more upmarket finish to the interior, it easily out performed it on the road as well.
The GT6 had a smooth and more refined six–cyclinder 2–litre engine, whereas the MGB had a not so smooth 4–cylinder 1800cc unit. In non–overdrive form the GT6 could accelerate up to 70 mph in second gear and reach that speed in a significantly shorter time than the MGB.
It wasn’t all about straight–line speed though, as the GT6 from the Mk2 onwards, with its fully independent suspension system, not only gave a better ride, but it also handled very well.
No Triumph GT6 Convertible
Some pundits have suggested that if Triumph had officially produced a soft top version of the GT6 the car might have enjoyed a higher profile. Certainly there was enough interest in such a version, and MG sold both soft top and coupe versions of the MGB in large numbers. Perhaps it was a concern at Triumph a soft top GT6 would have adversely affected sales of the Triumph TR6.
If you scour the classic car classifieds, or trawl the pages of Ebay, occasionally you will see a soft top GT6 advertised for sale, but these will be customised Spitfires. As the Spitfire and GT6 shared the same chassis and running equipment it is not difficult to build a convertible GT6 by transferring the necessary GT6 bits to a Spitfire.
If you ever try it for yourself you will even find there are two sets of gearbox mounting positions, one set for each model, as Triumph produced one universal chassis for both Spitfire and GT6.
Although no official announcement was made, Triumph GT6 production ceased on 30th November 1973 after the last two cars were completed. The last of the Triumph GT6’s were sold from stock in early 1974.
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The Triumph GT6