1967 TRIUMPH TR4A ROADSTER

In 1961, the TR 4, designed by Italian Giovanni Michelotti, was introduced. The new body, completely different from the former body, used the chassis and drive train of the previous model TR3A without change. 4.7 inch longer than TR3A, 4.3 inch wider on the front and rear track, the first TR4 was manufactured on July 18, 1961. Remaining in use for the TR4, the TR3A’s 121.5 cu.in. 4-cylinder TE 20 Ferguson engine’s size was increased to 130.5 cu.in. The 104 bhp engine also used twin SU carburetor. With this modification, TR4 reached 110 mph. The optional 134.2 cu.in. supercharged engine version achieved 200 bhp power. Furthermore, power-controlled overdrive system was offered as optional transmission.

The last TR4 was replaced by model TR4A with a renewed chassis on January 6, 1965. For the rear suspension, the roadster transitioned to independent IRS (Independent Rear Suspension) system and its leaf springs were removed. Developed for a more comfortable sports car drive, but considered a complicated system, IRS was used in 75% of the TR4As. Its 25% was marketed with the old system rear axle of the TR4s upon request of the vendors. TR4A was the first automobile with optional axle. The three TR4As using the IRS system came first, second and third in the 1966 Sebring race.

TR4, produced in 40,253 numbers and TR4A, produced in 28,465, also were assembled in Australia. Both models had hardtop with curved back window. Porsche Targa style “Surrey Top” roof was optional. In 1965, TR5 featuring the 6-cylinder and the American version TR 250 featuring injection, the same body and looks, and two carburetors, replaced TR4.