I haven't done the 55 yet but I took the C43 on a track; it loses out on twisty tracks due to the high weight. 964CS and Subarus will climb all over you in a multi-lap contest on a twisty track. On a straighter setup you will be up with the 911's but only just...
Let me know how the E55 does I am very curious.
No matter what I buy I will end up doing springs and struts and other things to it. I just can't leave them alone. Both the 911 and the WRX are rather heavily modified for street and track use.
rsr911, i have an '01 e55 and a 911, c4, 3.6 awd porsche. in a straight line you should be able to stay close to/ beat the porsche, unless your comp is an awd. i had occasion to turn my traction system off today on the merc and couldn't get off the line for the wheelspin! tjn[:p]
I took my E55 to a nearby track once just for fun. On the larger, high-speed bends and straights it does fine. The weight and lack of LSD are a real hinderance in very tight corners or severe elevation changes though. I didn't have any coolant or brake temp issues, which was fairly surprising to me for as hard as I was driving the car.