1973, Triumph, TR6
-
Category
-
PostedOct 14, 2025
-
Views74
Construction of the TR6 was traditional body-on-frame with four-wheel independent suspension, front disc brakes and rear drum brakes. All TR6s were powered by Triumph's 2.5-litre straight-6 engine.
The TR6 featured a four-speed manual transmission. An electrically switched overdrive made by Laycock de Normanville was available as an option. On early cars the "A-type" model overdrive was used and was able to be activated on second, third, and fourth gears and provided a 22% gear ratio reduction. Later TR6s had a "J-type" model overdrive able to be activated only on third and fourth gears but with a 28% gear ratio reduction.
Other notable features included aluminium semi-trailing arm independent rear suspension, rack and pinion steering, pile carpet on floors and boot, bucket seats, full instrumentation, 15-inch (380 mm) wheels and depending on the market, Michelin asymmetric XAS tyres that dramatically improved the handling. The optional steel hardtop required two people to deploy. The dashboard was a light shade of flat cut walnut veneer over plywood with a thick coating. Overdrives and hardtops were more commonly selected options, while a rear anti-roll bar and a limited-slip differential were rare.
1973 and earlier models produced 150 hp while later models were detuned to 135 hp
This car was purchased as a wreck. The front end had been modified, and a significant amount had been planed off the cylinder head to increase the compression ratio. The engine was not running when I purchased it. I rebuilt the front, including both left-hand and right-hand guards, and repainted the entire car in Triumph White. I also overhauled the Lucas mechanical fuel injection system and calibrated it using a manometer test bench at Air New Zealand.
Due to the high compression ratio caused by the excessive planing of the cylinder head, the engine would not rev above 3,000 rpm. I fitted a Capacitive Discharge Ignition (CDI) system, which solved the issue.
Front wheel drive
Rear wheel drive
Four wheel drive
Limited slip differential
Overdrive


