BMW 5-Series Evolution
Evolutions and revolutions – can you see the pattern? – click to enlarge

For BMW fans and potential owners, 2010 is the year that we’ll see the ‘eagle-eyed’ E60 be replaced by the all-new F10 here in Malaysia. Many view the F10’s design to be a much more conservative one compared to the E60, especially when you take into account the stark difference between the E39 and E60, and now between the E60 and the F10.

We all know that BMW designs usually follow the revolution and evolution cycle. The E60 was a revolution of the E39 and this F10 is supposed to be an evolution of the E60’s. But how exactly did BMW end up with how the F10 looks like, or with all of its other cars for the matter? I recently found out how right at the headquarters of BMW – the mothership as they call it – Munich.

How a car ends up looking is the result of so many factors – exterior and interior size requirements, crash compatibility requirements, aerodynamics requirements, as well as the actual aesthetics design direction itself. Sometimes crash tests alone can dictate how an entire generation of cars look like – I’ve heard many classic car owners lament on how there was a time where a revised US crash test ruling completely changed the course of car design.

But first, we check out where all the design takes place. The design of a new BMW takes place in the group’s Research and Innovation Centre. This is called the FIZ, which is an acronym for the same name in German language. The FIZ was designed to promote convenient and active dialogue between all the different teams that come together to design a car, down to the building’s very architecture, layout and structure.

According to a long-term study by the MIT, 80% of all innovative concepts and ideas are the result of effective personal communication between individuals. The BMW 5-Series is the first car that has benefited from the new FIZ Project Building, which started operations about 5 years ago.The FIZ Project Building is divided into a Central Area with four double floors, and a Ring Building covering 5 floors. This provides a gross work area of about 968,000 square feet.

Specialist work areas are laid out around an Inner Court within a Central Building in the middle. They are able to observe the latest developments in the car designing process at any time just “next door” to their own work area. Rooms are light and airy and located in close proximity.


Click to enlarge

And now to the actual development of the car. A new model usually takes a period of several years to develop, so this actually means that the F10 was developed while Chris Bangle was still in BMW. The features and requirements of a new model is defined in a “Package Plan” right from the beginning – usually about 5 years before the planned production start. It is during this initial phase that the designers start creating the first few scale models and renderings. The design process is split up into three phases – Understanding, Believing and Seeing.

It is under the Understanding phase which is where the features of the Package Plan is defined. You have to set targets for the car, things such as the desired wheelbase (which seems to keep growing and growing over the years), luggage compartments capacity, engine range (you need to design an engine bay that will clear all engines), interior width, safety requirements, and etc.

Then under the Believing phase, all the exterior designers come up with their own personal drafts and designs on how they think the F10 should look like. They compete with each other in a ‘creative contest’ of sorts, of course under the guidance of the Head of BMW Group Design.

At that time, Mr Bangle was the head of the entire group design while Mr Adrian van Hooydonk was the head of BMW design. Adrian is now both the head of the entire group design and the BMW marque design, while others are in charge the Rolls-Royce and MINI brands.

A few clay models based on these drafts and concepts are made and in an elimination process by the board, these drafts are eliminated one by one until finally the end result is selected. By this point, 2 years have passed and the final choice between the final two clay models is made about three years before the intended start of production. The clay model is 1:1 in size, which means it is the actual size of the intended production car. The clay model is covered by a special surface film similiar to Titanium Silver Metallic paintwork.

The designer whose design was picked as the final design for the F10 5-Series is 44 year old Mr Jacek Frohlich. I am guessing that the board is more than happy with his work with the F10 – he has just been promoted to the new position of Director of Exterior Design at BMW, replacing Anders Warming who penned the new Z4.

Next we have the Seeing phase of the design, which presents the design’s exterior and interior in all details for further refinement. The car’s interior design has already been chosen – the same man who penned the interior of the 7-Series and 5-Series GT. They are all rather similiar at first sight but have subtle differences about them.

But sometimes taking a design that just “works” and then altering it may create new problems that need solving. For example, while the 5 GT had some wood trim on the doors that connected with the wood on the dash, the wood on the door got thinner as the wood moved towards the rear. This was a design that’s pleasing to the eye.

But for the 5-Series Sedan (and presumably the Touring), the designer wanted the wood trim to continue to stretch towards the rear of the cabin. This meant that the wood would appear too thick. To ‘fix’ this, BMW added a trim bar to the bottom of the wood and added an upward swing where the dash and the front doors met. This is so that the optical impression of the trim’s width would be reduced and I must say it worked.

But all in all the interior designs are significantly more attractive than the boring and symmetrical ‘hammerhead’ design that the E60’s interior employed. With these new series of interiors, we have finally gone back to the driver-oriented BMW dashboard, though I am guessing this will probably incur more production costs as the design of certain features are no longer as symmetrical as the E60’s?

The clay models are scanned into a computer with laser scanning. The development process is now taken into virtual reality, powered by a system that can put to shame the most powerful of 3D gaming rigs you can think of! Virtual designing methods are used for various design processes including the rapid prototyping of individual components. The powerful virtual reality computer system that BMW uses is called the Powerbench.

VIDEO: BMW Powerbench Demo

The Powerbench can create a smooth and fast high resolution rending on a large reverse projection wall measuring about 6 meters in width and 2.7 meters in height, allowing the designers to view their designs virtually. The total image resolution is about 4096 by 2160 pixels. That’s about 4 times the size of 1080p HD resolution. Each pixel measures 1.5mm in size. This allows the system to bring out the finest of details of the design being worked on, down to the curvature of the kidney grille or the seam pattern on the seats. Powering the Powerbench is a network of 23 high-performance computers with high-end graphic cards. And this is just for the 2D projection.

Powerbench is also capable of 3D projection. This uses an additional floor projection unit about 6 by 2.4 meters. The observer looks at the 3D images through special glasses, and the position of the pbserver within the projection area is monitored by 8 cameras. This takes into account the position of the observer and adjusts the 3D image for a more realistic presentation. This allows the observer to change the perspective of the model being presented from different distances of angles.

Every single degree of curvature of the sheet metal is there for a reason. You have to take into account aerodynamics, the way it looks, the way it reflects simulated light, as well as the feasibility of whether the metal can be made the way the designers want it or not, both in technical terms and cost terms. BMW showed us how slight differences in curvature can result in a completely different effect when it comes to the light play on the surfaces.

Everything has to be just right otherwise you will not get an aesthetically desirable effect, instead there would be just random scattering of light on the surfaces. And the designers have to work within the constraints of a few pre-fixed points to allow the car to have the desired crash safety.

You may think that the Hoffmeister kink on the new F10 was easy to implement. To us who are not engineers, it may seem just like cutting a Hoffmeister kink-shaped hole in the side of the F10 and being done with it! If only engineering was that simple.

They said it was pretty hard to get the desired angles of the kink. The actual kink is easy to draw on paper but apparently the shape of the chassis metal behind it required some pretty intense and precise math calculations, as if done wrongly, the metal would just tear during the production process. This is because the kink was wrapped so far back into the C-pillar, resulting in a thin C-pillar going as far back as possible and the ‘kink’ kicking in at a tighter than usual radius. But Powerbench helped them develop an ideal solution.


Both the F10 exterior and interior designers having a chat in their creation

That’s basically how the exterior of the car was developed, as that was pretty much what the design workshop presentation was about. But I also do have some technical tidbits about the car to share with you. For one – yes, this new F10 shares a common platform with the 5-GT as well as the F01/F02 7-Series. The Rolls-Royce Ghost does share some components with this platform but BMW considers that platform to be unique.

The decision to base the new 5 on the 7 was not something that was decided later. It was something that was decided when the 7’s platform was being developed. It is significantly harder to design something large and then try to scale it down and cram everything that you require into the smaller spaces, so the reality is the smallest platform was designed first, and then scaled up into larger versions. The 5-Series Sedan will include all the high-tech features that the F01/F02 features, such as the rear axle steering for rear wheel drive vehicles.

The new F10 5’s chassis is about 50% stiffer than the outgoing E60’s. This will improve drive and handling but it is also something that was required due to the lengthening of wheelbase. The longer the space between the two axles, the more strengthening of the rigidity between the two axles are needed, for both driving dynamics sake as well as for side impact safety. There is just simply more area to hit since there is a longer passenger cabin.

Of course, all of this also contributes to the F10 being heavier than the E60, but thanks to tech such as the active air flaps in the kidney grilles, the end result is still a more efficient car – both in terms of fuel consumption and CO2 output. Now that’s impressive.

From what I heard, we’ll be able to see the end result of what the F10 project team worked so hard on (with the help of Powerbench) for about 5 years on our roads sometime in Q2 or Q3 this year. We’ll bring you a test drive report sometime next month so watch out for that!

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