[Racer20]

(Maybe the wrong forum. Mods can move it if they wish)

To sum it up, it's good. Really good. It's better than the E9X, better than the F10 M5. If you didn't order it, you're missing out IMHO. I need to refuel after a long drive (beer and a burger), but I'll be back in a couple hours with a proper review.
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I'm back. First, I want to clear up some misconceptions . . . the point of adaptive suspension is NOT to make the car more comfortable, it IS to reduce unwanted body motion and keep the car as flat as possible under all conditions of driver input and road condition. The adjustments that are made every couple milliseconds are targeted towards keeping the tire in contact with the ground and keeping the body flat. The challenge for passive dampers is that having enough damping to keep the body as flat as you'd want it often results in over-damping of the wheel, which means it will loose traction on a bumpy surface and ride poorly. Adaptive dampers work by providing much closer to the ideal damping rate for all conditions. An good adaptive damper can be more comfortable and compliant than a passive damper AND have better body and wheel control at the same time.

My benchmarks for adaptive damper performance (besides some prototype cars that I've tuned myself) are the E92M, Cadillac ATS 3.6 with MR, and the F10 M5. I consider these cars to be well tuned, but each has its faults that I'll get into later.

With that in mind, I can say that the F80 has the best adaptive suspension I've ever driven. It's pretty much how I would envision tuning the perfect car for myself, understanding the physical limitations of such a system. To break it down further:

Comfort Mode
This is where a lot of systems fall down IMO. Usually the middle mode is pretty good, but the comfort and sport modes are tuned as afterthoughts, and they are exaggerated on purpose just to be different from normal. The M5 is like this to some extent. Comfort mode is comfortable, but its floaty and the steering feels disconnected no matter what steering mode its in. The F80 on the other hand has no exaggerated float in comfort mode and the steering is still direct and precise. Road imperfections are felt, but they are very well damped and never intrusive. Body motions are a LITTLE BIT larger, but never jerky, bouncy, or floaty. Overall, the car is very smooth and calm, with little to no head toss or pitch. To me, it feels like what a well tuned 335i M-Sport should be.


Sport Mode
The car defaults to this when you start it up. If I'm on the expressway, I can actually feel the car firm up in sport mode. It breathes just a bit less and has more support in compression, especially in the rear. Any hint of extra movement in the rear is gone, but road texture isolation is still good, and impacts are still well damped. I didn't actually spend much time in sport, instead switching between comfort and sport+. The E92M and most MR cars seem to transmit a lot of road texture and small inputs due to either high friction or lack of compression damping range. This car seems to have enough range to deal with anything you can throw at it. I didn't encounter any crashiness in any mode today, but that's typically not an issue on the roads in Germany anyway. If I find a different story back home on Michigans moon surface roads, I'll edit my post.


Sport +
I dialed the car up to sport plus whenever I hit a twisty section. It's firm, but not overly firm. Small road inputs are still well damped, but the extra body control starts to tug at the rear of the car over uneven pavement. One of the narrowest, twistiest sections today also happened to have the worst roads. Not broken or cracked, but lots of patches and heaves that tossed the car around quite a bit. In sport +, the body and wheels were very well controlled. Combined with the precise steering and good kinematics (bump steer/roll steer, etc), I was shocked at how well the car tracked around these difficult corners.

Body roll
As the chassis engineer states in the interview that was posted today, comfort, sport, and sport plus all have about the same stiffness when you intially turn into a corner. Typically, when you first turn the wheel to enter a corner, the dampers will spike the compression or rebound quite high to immediately counteract the body roll. BMW did a great job getting this right, as body roll is balanced and well controlled in every mode. When sport + is selected for both steering and damping, the result is a car that turns in quickly with minimal body roll, and feels very linear and predictable. When they say anyone can get in this car and go fast, they are right. It's very intuitive.

Steering
Does the wheel communicate every pebble on the road through the wheel? No. But this isn't a lotus Exige. There is a bit of road texture that makes its way through, and as everyone else has stated, it's very accurate and the weight is good. I never found myself needing to correct, whether mid corner or at 90mph on the autobahn. I didn't push the front tires past their limit, so I'm not sure how well it will communicate that, but so far I have no complaints whatsoever about the steering. It works in concert with the dampers to provide a great driving experience.

Overall, I'm extremely impressed with this car. It feels light on its feet, smooth, and effortless, and the suspension, steering, transmission, and engine all work together to disappear behind the scenes when you're attacking a challenging road. To those on the fence, there's really no question in my mind that the adaptive dampers are a must have. The passive dampers are probably phenomenal, but it's not physically possible for them to be as good as the M adaptive at all these things.

I doubt the BMW chassis dynamics engineers are reading this, but if they are, I tip my hat to them. This is the best car I've ever driven. I really want to get a set of these off a car and put them on the dyno.