THE SUSPENSION OF THE BMW M3 AND BMW M4.

How?

Using intelligent lightweight construction we were able to take a considerable step forward in terms of driving dynamics. The role model here was the BMW M3 CSL, where reduced weight again permitted an increase in potential transverse dynamics. The axle design is completely new and entirely M specific, in other words no parts have been adopted from the base model. This elaborate design significantly enhances performance, driveability and response. The premise was to maintain the good driveability of the previous BMW M3 but considerably increase performance at the same time. You’ll be able to see this in the lap times achieved.

The new BMW M3 and BMW M4 are now offered with two different damper systems again: the standard suspension and the controlled Adaptive M suspension. What's new?
In the standard suspension there are new dampers. They enable much less phase shift in response as compared to the predecessor system, and therefore even more grip. Customers will notice this clearly when driving over poor surfaces, for example.

What does “less phase shift” mean?
A damper converts a speed into a force so as to keep the wheel on the ground. The faster the wheel passes through the rebound and compression phases, the greater the force. If you look at this in terms of the frequency of superstructure excitation and wheel excitation, the correct phase between speed and force is now applied across a much expanded operating range. When the phase between excitation and damping is not right, the damper becomes a spring at some point – increased wheel load fluctuations occur and road surface contact is impaired.

Can this result in an overlap of the setting ranges? In other words, even the COMFORT setting could lead to the suspension being tightened significantly if required by the relevant manoeuvres?
There are manoeuvres where the COMFORT setting is just as sporty as in SPORT and SPORT PLUS. Maximum damping power potential is used here, regardless of the setting.

You already mentioned that you yourself use the SPORT on the Nürburgring Nordschleife and SPORT PLUS on level race tracks. What about when you’re driving in everyday traffic?
There I definitely use the COMFORT setting (laughs). The new BMW M3 and BMW M4 now start for the first time in SPORT mode. My M1 button at the steering wheel is pre-set to DSC OFF, with steering and dampers in COMFORT.

Last year you were at Nürburgring doing set-up runs with the DTM driver Bruno Spengler. How did that go?
It was remarkable how quickly Bruno felt his way to the limit. And that’s what’s so striking about the BMW M3 and BMW M4 for the normal driver, too: the car always remains eminently driveable in spite of the extreme grip potential. That’s always the difficulty in general: the closer you get to the physical limits in terms of the car’s balance, the greater the challenge in getting the car to respond quickly. As you can see in the new BMW M3 and BMW M4: the driver simply gets in, drives off and can immediately drive fast, on the race track for example. And that's a key aspect of the M philosophy: driving response and the car’s reactions always have to be predictable and convey a sense of trust.

Did the test runs with Bruno Spengler and Timo Glock contribute to achieving this?
Bruno had an idea regarding the transverse rigidity of the tyres and we implemented that. Ex-Formula 1 driver Timo Glock’s input in terms of the steering was also taken on board. It was exciting to see how much overlap there was between the racing drivers’ point of view and that of our set-up experts and how quickly they came together.

Mr. Barbisch, thank you very much for the interview.