Mods and Consequences
The sleek MkIII Supra is already a great cruiser, but you can make it far more accomplished
When it comes to cars as appliances, Toyota has arguably scored more bullseyes than any other carmaker – yet this normally conservative company has also produced some of the most enticingly affordable performance cars too, such as the MR2, Celica and Supra. The last-named has traditionally been Toyota’s highestperformance model – but there is still plenty you can do to improve it.
The third-generation Supra, codenamed MA70, arrived here in January 1987. More of a grand tourer than a sports car, it came with lots of kit and a normally aspirated straight-six. This engine would power all UK-market MA70 Supras, with a turbocharged version being introduced at the same time that the model was facelifted in January 1989. A catalytic converter was fitted to the Turbo as standard, and by the end of the year, normally aspirated editions also featured one.
All officially supplied UK Supras were fitted with the double overhead-cam 2954cc engine with electronic fuel injection – there were twin-turbo 2.0- and 2.5-litre engines for other markets. With cooling already marginal, even before embarking on power increases, it’s key that the cooling system is in fine fettle – and ideally upgraded. Expect to fit a good replacement radiator, a decent head gasket (Adjusa or Toyota), new head bolts (ARP), plus new coolant hoses (there are lots of small ones in addition to the main visible ones) with either silicone or factory replacements.
If you’re increasing the engine power, a bigger aluminium radiator together with a multi-layer metal head gasket and uprated head studs (supplied by ARP) should be used. However, a higher degree of corrective work will be needed to prepare the engine mating surfaces for this to seal successfully, so you’ll need to factor in the costs of lapping the head by a reputable machine shop and also potentially the same to any block surface damage.
Supra buyers could choose between five-speed manual or four-speed electronically controlled automatic gearboxes, the latter proving very popular. The Turbo’s R154 gearbox is desirable due to its strength, while the normally aspirated car’s W58 unit isn’t quite as tough – although it’s still pretty strong.
‘If you’re increasing the engine power, a bigger, aluminium radiator, multi-layer head gasket and uprated head studs should be used’