There’s nothing like an old V8 to make a new race car even more exciting. The Porsche 963, for example, uses an evolution of the screaming 4.6 first used in the RS Spyder 15 years ago. Now BMW is following suit (kind of), confirming that its new M Hybrid V8 has a combustion engine with roots in an old DTM car.
Back when DTM was using properly exotic race cars unique to the series (and wasn’t just another GT3 championship), BMW’s M4 DTM was using a ‘P66’ V8. It was a naturally aspirated 4.0-litre 90-degree unit, making peak power at 7,500rpm; for 2017 and 2018 it produced more than 500hp and was known as the P66/1 - that’s the engine that’s been used to build the M Hybrid’s V8.
Which is odd, because the new LMDh’s engine is twin-turbocharged, and BMW already has a twin turbo V8 race engine - the P63 as found in the M8 GTE. But apparently that was too heavy. The four-cylinder engine in the later M4 DTM was dismissed on the grounds of durability. A new engine would have been too expensive and time consuming to create. So P66/1 it was - keeping up?
There’s plenty more to recommend the V8 than merely being light and tough, too. “It is a huge plus that we were able to make use of existing materials such as steel and aluminium from BMW’s time in Formula 1 for the basis of the engine, as well as for individual components – like shafts, housing and small parts” said Ulrich Schulz, Head of Drivetrain Design at BMW M Motorsport. Interesting that BMW’s time in F1 can still have an influence.
Then the hard work on the P66/3 could begin, given it was an originally an N/A V8 that needed to be turbocharged and work as part of a hybrid system. A middle-ground P66/2 was made by BMW, adding the two turbos and modifying the crank, which was then extensively put through its paces on the test bench. Only then was the P66/3 given the go ahead, with a little bit of help from the Formula E team in getting the electric motor integrated.
And that seems like the easy bit, in truth, with the P66 requiring its injection system to be rebuilt for direct injection, having its block and head recast and then the pair of turbos fitted. “Converting the normally-aspirated P66/1 engine into a bi-turbo and then working with the electric drivetrain colleagues to turn it into a hybrid drive system was very complex” said Schulz, presumably underselling the challenge somewhat.
What an engine they’ve come up with, though. The 3,999cc of V8 produces approximately 640hp and 479lb ft, revving all the way to 8,200rpm. That’s before the electrical assistance too, don’t forget. “We now feel that nothing is standing in the way of testing” added Schulz.
Which is good news, as there’s really not much time for it. With the engine first started at the end of last month, the end of July will see a rollout in Italy, with ‘intensive’ testing to follow. The Daytona 24 in January is sounding more exciting by the week.
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