Reading time: 2 – 4 minutes
So, there we were in Alicante. Heinz Krusche opened his technical discussion on the E89 Z4 with a little background behind the project. This was revealing in itself.
We spoke in the lobby of the launch hotel. Once we’d got drinks (Krusche: cappuccino. Me: OJ. PR men: water), it was down to business. When did development of the E89 start?
3 years ago, said Krusche, but they only started drilling down to production finites 18 months ago. Prior to that, they were assessing 2 types of car – both ‘flexible’ roof and hard top. Interesting… as was the revelation that there was a philosophy change with the E89, towards ride.
This had to be balanced with an internal BMW edict, that every single car has a different concept to one another. Crucial point, this: just as the 5 cannot simply be a shrunken 7 or a big 3, so the Z4 should not be a quasi-M, or a 135i Coupe with 2 less seats.
Much of the on-road testing happened in Munich – specifically, the country roads around the factory. They’re twisty enough to be a good base. Sweden’s Arjeplog was for low-friction testing, while Miramas was the base for dynamic stuff.
‘We also visit the Italian Dolomites 4 times a year, for big department handling tests.’
Specifics on that new chassis philosophy, explained Krusche, centred on a shift in thinking within BMW, that has been in place since the 1 Series Coupe. In a nutshell, to go softer on the springs, but stiffer on the dampers.
The ICM chassis controller helps, especially on cars with Adaptive M suspension. Krusche says that here, ICM is not as all-encompassing as on the 7 and X6, but is still a trick bit of chassis software centralisation. Bosch’s latest ESP 8.0 also brings finer finesse than ever.
2 different chassis setups were engineered; standard and Adaptive M. the fact that ‘Comfort’ Adaptive M is even more comfortable than the standard suspension, yet ‘Sport +’ even sportier than the E85 Z4, is crucial to its appeal.
‘It widens the breadth of the car’s abilities,’ says Krusche. For just £930? Tick the box for me, definitely…
Before we got into the real deep stuff, I asked Krusche who’s responsible for testing it all and pulling it together. Driving gods, such as him? Partly, he answered.
‘But we also have people who are not such good drivers. They are brilliant engineers, yet drive more like the average guy on the street. Their input is crucial, too.
‘This is how we make cars that are great to drive by everyone, not just race car drivers.’
Krusche. The most savvy dynamics engineer in the industry?