BMW will shortly start an intensive interval of testing for the BMW M Hybrid V8, with which BMW M Motorsport can be battling for total wins in 2023 within the IMSA GTP class of the WeatherTech SportsCar Championship. The venture had already reached a key milestone earlier than the rollout: the profitable fire-up of the hybrid drive system after set up within the check car on the finish of June.
The BMW M Hybrid V8 is powered by the P66/3 eight-cylinder turbo engine with supplementary electrical drive. The combustion engine is predicated on the DTM unit used within the BMW M4 DTM in 2017 and 2018. Throughout two phases of reconstruction, it underwent complete changes to fulfill the stringent necessities of the LMDh (Le Mans Daytona h) hybrid drive system.
BMW M Hybrid V8 engine
Ulrich Schulz, Head of Drivetrain Design at BMW M Motorsport, and his group had initiated an analysis to find out which race engine could be greatest fitted to conversion right into a high-performance hybrid drive system, even earlier than the BMW Group Board of Administration had given the inexperienced mild to the BMW M Motorsport entry within the LMDh class in June 2021.
Time constraints and the necessity to take into account sustainability features which are taking part in an ever extra crucial position in motor racing, in addition to the car trade generally, meant that returning to the drafting board to design a totally new engine and constructing it at nice value was not an possibility. Consequently, the query was to determine which confirmed race engine would greatest meet the stringent necessities and specs of the LMDh laws.
The normally-aspirated P66/1 eight-cylinder engine used within the 2017 and 2018 seasons within the BMW M4 DTM was the one which bought the nod. As a completely load-bearing element within the BMW M Hybrid V8, it had the benefit that it could possibly be utilized in a monocoque chassis with out an extra subframe and it was additionally the one that the majority carefully corresponded to the regulatory necessities after conversion to a hybrid turbo engine.
Throughout the analysis part, we additionally took a take a look at the P48 four-cylinder turbo engine from the BMW M4 DTM and the P63 eight-cylinder turbo engine from the BMW M8 GTE, however potential issues with the sturdiness of the P48 and the heavy weight of the P63 had been adverse concerns. It’s a large plus that we had been capable of make use of current supplies resembling metal and aluminium from BMW’s time in Method 1 for the idea of the engine, in addition to for particular person parts—like shafts, housing and small components. That saved us time and some huge cash and was due to this fact environment friendly and sustainable.
Effectivity is a crucial issue for this venture, as we’ve got a really brief time period accessible between getting began and the primary racing look at Daytona in 2023. Changing the normally-aspirated P66/1 engine right into a bi-turbo after which working with the electrical drivetrain colleagues to show it right into a hybrid drive system was very complicated. Due to the experience, the nice collaboration and the excessive stage of motivation of all departments, we managed to finish the fire-up of the entire drive unit only a few weeks in the past. We now really feel that nothing is standing in the way in which of testing.
—Ulrich Schulz
The primary part noticed the normally-aspirated P66/1 DTM engine transformed into an intermediate engine, named P66/2, primarily by adapting two turbochargers and adjusting the crank drive. The main target was on sturdiness, elevated efficiency and temperature administration for the engine. The P66/2 accomplished quite a few testing models, together with full racetrack simulations, on the check bench.
The following step was the creation of the P66/3 race engine, together with a twin-turbo model, changes to the precise necessities of the Dallara chassis, closing exhaust system, oil tank, cabling and integration of the high-voltage atmosphere. The cylinder block and cylinder heads had been recast within the BMW Group foundry in Landshut (GER) and the injection system was rebuilt for direct injection. Engineers who already boasted loads of expertise with electrical drive methods from the Method E venture had been testing and integrating the electrical motor in parallel.
Specs for the P66/3 engine within the BMW M Hybrid V8
| Title | V-shaped Otto four-stroke twin-turbo engine |
| Capability | 3,999 cc |
| No. cylinders | 8 |
| Cylinder building | Solid aluminium cylinder block and cylinder head, cylinder lining as iron layer in LDS process |
| V angle | 90 ° |
| Bore | 93 mm |
| Stroke | 73.6 mm |
| Cylinder spacing | 102 mm |
| Valves per cylinder | 4 |
| Engine pace | max. 8,200 rpm |
| Output (regulated) | approx. 640 hp |
| Torque | approx. 650 N·m |
| Injection | Excessive-pressure direct injection at 350 bar |
| Oil system | Dry sump system with six-cell oil drain pump and oil tank |
The unit that varieties the hybrid drive system within the automotive consists of the e-motor, the inverter and the high-voltage battery. There’s a separator clutch between the electrical and combustion engines, enabling fully-electric driving—within the pit lane, for instance.
The 2 drive parts had been linked within the automotive for the primary time on the finish of June. The primary fire-up for the hybrid system was successful. On the finish of July, that can be adopted by the rollout in Varano de Melegari (ITA). The intensive check part begins instantly after that.
