TR4/4A & 5

From the introduction of the TR2 in 1953, through the TR3 and 3A developments the sidescreen TRs had become highly successful cars on the rally scene for years, with some surprisingly modern features, particularly front disc brakes, first introduced on the TR3 in August 1956. The early cars had the 1991cc wet liner 4 cylinder engine developed from the unit first used in the Standard Vanguard, but by 1959 the TR3A could ordered with the optional 2138cc unit, offering improved torque. By this time work had commenced to come up with a more modern replacement TR model with some creature comforts. Giovanni Michelotti came up with a few prototypes based on the standard or longer wheel base and wider track TR3A chassis. A modified version of one, known as Zoom, was made in glass fibre and formed the basis for the TRS Le Mans cars of 1960/61. Michelotti's task was made difficult since Triumph management took a long time to arrive at a final chassis design for the new car. In 1960 it was decided to keep the standard wheel base TR3A type chassis, but with a four inch wider track and rack and pinion steering. The result was a very appealing body style combining the best features of all the earlier prototypes. This car entered production in July 1961 as the TR4. The body used an optional two piece hard top of which the steel roof panel could be removed, leaving the rear window and surround in place for open air motoring without the buffeting experienced in a full roadster. An optional 'Surrey' soft top and frame could be carried on board in case of showers. It was a further five years before Porsche introduced its Targa top 911 with removable roof panel, although in fairness that top could be carried on board, whereas the large TR4 roof panel has to be left at home! The 2138cc engine was standard on the TR4 but, strangely, the 1991cc unit was offered as an option although few customers ever went for it and it was soon dropped.

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