BMW has detailed development of the engine behind its M8 GTE endurance racer. Based on the 4.4-liter V8 engine that first featured in the M5, the S63T4 unit is claimed to be the brand’s most efficient engine yet.
During development, more than 500 engine design drawings – and another 500 drawings for the powertrain – were created. The result is an engine that BMW Motorsport claims is the most efficient it has ever developed, delivering 500-600ps or more than 600ps (depending on the specification).
The P63/1 powertrain passed its first performance test at the modern BMW Motorsport test rig in Munich, Germany, on January 20, 2017. This was a special moment for the engineers – as was the roll-out of the car on July 1, 2017, and its race debut at the 24 Hours of Daytona on January 27, 2018.
The goal during development was as clear as it was ambitious: to develop the most efficient engine ever to power a BMW race car. To achieve this, BMW focused on a base engine ideally suited to the high demands encountered in motor racing. Working closely with the developers at BMW M, the decision was made to use the BMW S63T4, a V8 engine with BMW TwinPower turbo technology, which was first used in the new BMW M5.
As per regulations, the cast parts in the engine block and cylinder head were adopted without modification from the production power unit. Both components were made in the light-alloy foundry at BMW Group Plant Landshut in Germany.
Aside from the regulated cast parts, the engine in the BMW M8 GTE – containing approximately 2,300 further components, including 985 unique parts – required comprehensive modifications.
Of these parts, 181 were derived from series projects, while more than 700 were specifically developed for the P63/1 or added from other BMW Motorsport racing engines. The engineers reduced the capacity from 4.4 liters to 4.0 liters, in line with regulations for the GTE class. The new design of the crank drive involved the implementation of a flat crankshaft, which brings with it the advantage of a regular firing order.
The geometry of the combustion chambers, including the inlet and outlet ports, was also modified to ensure that the P63/1 is designed for the demands of racing. Comprehensive modifications to the intake and exhaust system, and the complete redesign of the turbocharger, has improved efficiency.
Among other things, this resulted in an engine that burns fuel quickly and comprehensively with optimal timing – at a maximum temperature of more than 2,100°C. This allows the P63/1 to achieve efficiency levels well above 40%. This helps the drivers get the most out of the BMW M8 GTE on the track.