I ran my M5 on several tracks and it was very capable and very fast. That being said, it needs the full Dinan suspension package to be sorted. With stock suspension it pushed way too much, too much body roll, and generally not fun for me.

I was able to keep up with any car on the track and even on tight auto-x tracks the car performed quite well.

FWIW here are the mods.

2006 M5 Interlagos Blue / Black / Aluminum / SMG
-carbon filter delete / bmw ipod kit / evosport crank pulley / angel-i-bright / Dinan stage 2 suspension / BBS RGR 19*9 19*10 w/PS2 / Dinan 3.91 / BMC air filters / Dinan muffler / RPI intakes / Dinan camber-caster plates / Dinan monoballs / RPI-Powerchip software / RPI block-off plates / RPI headers / RPI Oil Cooler

 

heavy-yes
understeer-yes
fun.as.heck.to.chuck.around-hell.yeah

 

I've tracked my (recently departed) M5 (in Texas) even, and it's pretty fun, but absolutely not a track car.

Heavy - yes (it's like a fat girl wearing all-black. It somewhat masks the weight, but you know it's there)
Understeer - depends. On corner entry, you really need to gently ease the front in, especially in highter-speed corners. It's a lot less "Get in there, son", and a lot more "Would you mind awfully if I asked you to go around this corner?". In steady state cornering, the front will wash away under light throttle. Mid-corner to corner-exit, more aggressive throttle will bring the back out.
Fun - it can be, but I just never felt comfortable leaning on it. B-u-t, I also have a dedicated race car, and with that frame of reference, the M5 is just too expensive to push hard for too little speed (but it was nice to hit 115 at the end of a straight where my race car currently only hits 97).

The biggest issue with tracking an M5/M6 in TX is heat. It's basically a race whether the tires get greasy, the brakes get mushy, or the engine overheats first. Either way, you get about 3-4 laps on a summer's day. The brakes can be fixable with pads and fluid, but the engine simply generates too much heat for the cooling system to shed, and the weight of the car tortures your tires (and I had R-compounds on there).

If I were set on tracking a BMW, I'd look at an E46 M3 first, a Z4M second, and an E36 M3 third. That's assuming you want some horsepower for the giggles, and plan on driving it around town. The E36 would be the most involving, but would feel underpowered in normal driving.

The M5/M6 cars are great street cars, but lousy track cars.

 

tracked it at the Nurburgring. Underbraked for the track and too heavy..great for road use though and bloody quick..see my vid below of delimited run on the A4:

YouTube - m6board.com Member Ronan does 330 km/h (205 mph) on Autobahn

 

Pmac - awesome reply, detailed, PERFECT.

Def going back to looking at a standard Carrera S, less 'stuff' but more scalable.

 

M6 track car? Yes?

 

Turner's "M6" is a complete tubeframe race car with an s62 (5.0L V8). Aside from the basic aero its nothing like the street car.

Pick up a recent carrera or m3, massage the suspension & brakes a bit and you have a fine occasional weekend track day toy that doesn't compromise its everyday streetability

 

ok.....we can top this car by......


that >