Downsizing? For Karl-Otto Noelle, the concept is nothing new. Back in 1989, the engine expert employed twin turbochargers to extract 360 bhp and 520 Nm from a straight six engine – in the legendary Alpina B10 based on the BMW 5 series (E34), then the world's fastest sedan, of which over 500 were built. "The V8 naturally aspirated engines in the production cars burned significantly more gasoline and generated an average of less than 300 bhp at the time," recalls Noelle, who was then Head of Engine Development at Alpina before he set up on his own in 1993.
The former Pierburg developer started by increasing the displacement of the BMW eight-cylinder engines. The biggest seller proved to be the 5.0 liter version of the original 4.4 liter V8 with an output of 380 bhp (standard: 286 bhp) as featured in the 540i, 740i and X5. The same attention was lavished on the straight six engines in the 325i, 525i and Z1, which Noelle fitted with a 3.0 liter variant: "My first three-liter car," as he remarks today with a smile.
However, the enormous increase in power of these engines, which also featured special pistons and camshafts, could only be called on with the help of a highly complex technical adjustment to the digital engine electronics: As one of the pioneers of performance map optimization, Karl-Otto Noelle discovered very early on the potential that this type of performance boosting could offer even in standard production engines. The "chip tuning" industry of today was born – and led him immediately to the BMW diesel engines. The first test published by a specialist magazine of a BMW 325 tds uprated by Noelle using performance map optimization of the original engine electronics caused a furore: With a barely measurable increase in consumption of just 0.1 liter/100 km, this "Greased Lightning" (the title) offered sports-car-like performance and significantly outclassed a 328i in terms of in-gear acceleration.
The engine specialist has always had a particular passion for the M derivatives: For the previous M3 with its high-revving V8 engine, Karl-Otto Noelle developed a 5.0 liter power plant pumping out 500 bhp, as well as a 650 bhp, 6.0 liter variant for the ten-cylinder engines in the M5 and M6.
The current BMW engine range makes the heart of this acknowledged turbo-charging aficionado beat faster even though "the technical input required to optimize the performance map of the gasoline and diesel engines of today is extreme, and requires a great deal of experience and know-how," stresses Karl-Otto Noelle. At the end of the day, all this "extra" driving pleasure, individuality and emotion must be achieved without sacrificing everyday usability, reliability and, particularly with the diesel models, exemplary efficiency.