I too just had my 550i on a track. The 550i did quite well on track at Virginia International Raceway. It was only my second time at VIR so I spent most of the first day relearning the track. For those that don't know VIR, its challenging to learn with lots of combination curves and elevation changes that feel great only when fast and smooth. I think I equaled or bettered my best lap times in an '02 M5. It doesn't have quite as much power but I did hit 130+ on the back straight.

Being a Porsche Club of America event, there where tons of Porsches but there where many BMWs, Vettes, and even a couple of Ferarris. I took close to 1200 pics as well. Here are just a few from Saturday.

Its hard to compare the 550i to the E39 M5 since I was last at VIR with it 2 years ago. I ran a 650i once at CMP. I need to get the 550i to CMP for an absolute comparison of all 3. But I can give my impressions of it...

Performance: Very similar to the 650i for obvious reasons. The only gears I used on track are similar ratios to the 650i 6 speed manual and similar to the M5 but a lower redline and speeds in each gear. I easily hit 130 mph on the back straight and had some left giving myself time to gather the suspension over the crest of the hill and pick a braking point. That is real close to what I did in the E39 M5. It was waay faster than a Lotus Elise and a base 911 or Boxter. I kept catching them and having to slow to 110.

Sport Automatic: I loved it on track in full manual mode. I only ran DS mode the first session. It would often pick the wrong gear. In manual mode, it did perfect, fast, yet smooth (non disruptive to the cars balance) 1 or 2 gear downshifts over and over. For upshifts, I let it automaticly upshift at 6200 RPM. Especially during full throttle runs down the straights. There were no issues with the paddles on the wheel since you shouldn't be in a turn when shifting anyways. It's definitely better than my skills with a manual tranny.

Handling: I'd say it feels 1/2 way between the "relatively big feeling, slight understeer, weight transfer" feel of the E39 M5, and the "tight absolutely no lean, neutral" feel of the 650i. With ARS, it doesn't lean but you can feel the weight transfer and it will push (understeer) when not driven smoothly. Overall, my instructor (and myself) where quite impressed at how well the 550i took to the track, especially after I started getting it smooth and fast.

I ran it in DTC mode a lot and full DSC off a lot. DTC mode still limits how hard you can punch the throttle to balance the car in certain situations. It rarely had to intervene otherwise. IE, it never had to come on to save my butt..... The tires didn't roll over 1 bit and provided plenty of feel. I ran them at 36 psi front and 38 rear. In 45 degree weather, the left front still got as high as 45psi hot but they felt good and consistent thoughout the 30 minute sessions. I did put quite a few miles worth of wear on them. Ultimately, the Contis were the limiting factor of the handling, especially compared to a lot of my run group that ran R compound track tires.

Brakes: Incredible! I could count on them lap after lap the whole weekend. They only got slightly softer but they never did fade. On the main straight, it was easy to reach a consistent 125mph speed and do a late full on threshold brake (almost to ABS activation) all the way into corner entry. On the back straight, I had less nerve to compress the brake zone to the minimum.

What's next? I may track it 1 or 2 times a year. I do want to find better tires but won't go to full treadless track only R compounds. There are few choices anyways in 19 inch sizes.

FYI, unfortunately there was one major incident. An instructor I've known for years lost his brakes going full speed into turn 1. He went hard into the tire wall which is way off track and totalled his Mustang. Thanks to a full cage he was fine with no injuries. Although I'm sure he'll be sore for days.....

 

Great review, Richard!

I wish I had checked my tire pressure. Maybe that would have saved the excessive wear I have on the outside edges

Having Brembo brakes would have been nice, eh? But if we're talking of tracking it 2-3 times a year kinda makes it pointless...am still tempted though.

 

Nice show:

 

If you are tracking every weekend I think they might raise a few questions but if it is a few times a year and you are gentle to your equipment it shouldn't be an issue. The most expensive component is tires $$$. You will have to pay for fluid changes prior to track events per BMWCCA rules.