This month, BMW M division celebrated the 10th birthday of the BMW M3 CSL (Coupe Sport Lightweight).
The BMW M3 CSL is regarded by many as one of the best cars to come out of the M3 division. The E46 M3 CSL is most notably distinguished from the standard E46 M3 by its various lightweight components. BMW claimed that the M3 CSL weighed 3,054 pounds, or roughly 10 percent less than the normal model.
But how did this special M car come to life?
PistonHeads sat down with Hans-Bruno Starke and Peter Schmidt, two of the people responsible for the creation of the M3 CSL. Starke’s role was the head of body and trim for BMW M and Schmidt was responsible for the chassis development.
Let’s see an excerpt from the interview.
When the decision was made to make a CSL variant of the E46 M3, what were the goals in terms of weight saving over that car? Did you have a specific percentage figure or was it just let’s make it as light as we can for so many euros?
HBS: “As light as we can. We can only make new components and parts that are going to be specifically designed for M. So the basic design requirements, the functional requirement that relates to the kind of parts that we want to do. We want to have a nice car, an optimal car for aerodynamics, and the function of the car needs to be perfectly designed for the M car.
“So it was all about reducing weight and making it lighter. We did have a figure in mind. We did have a target. We wanted it to go under eight minutes around the Nurburgring – that was the top target. So we had two options. You either increase performance, or you reduce weight. But you can also increase performance through the tyres.
“Now this is a mix of everything you see. We worked on the aero design, we worked on the chassis’ design, we designed a specific tyre combination and we also had the top performance of lightweight design – that’s what we realised with this car. We were able to design parts that had only been in the pipeline in BMW as pre-development. And now they came onto the road in that car and they used to be in the pipeline.”
So it was almost like a running, working prototype for certain technologies you were experimenting with?
HBS: “Yes, yes, it was. Like the carbon fibre roof – there had been pre-development projects from BMW before. Not here in M, but elsewhere in the BMW group, and this way we were using the concept of realising carbon fibre. So we were able to use already existing development in the group to realise this roof – it was there already. The development was in the group, you know.
“So with that we were able to realise and produce this roof as the first series component. Do you know it’s a small component of what we call the BMW i philosophy today, and that was the best use of the car, of the roof, and we rolled it out to various coupes afterwards: E92 M3 and M6, for example. So we rolled it out more times.”
So, you didn’t purposely design the carbon fibre parts on the CSL and think these are just going to be for the CSL? It was always with a view to expanding and putting that sort of technology on other M cars?
HBS: “Of course, there has always been a desire to do that, so after the project started we proposed these components and the first series use had the highest costs – that was the CSL. Then after developing the processes then of course you get competitive edges when it comes to price, so you can manage to stop the technology costing so much.”