@gbb357 - I got the data, and I have conceded that a 997 TT in the hands of someone who is willing to shift their car like they mean it ought to win reproducibly. I am screwing around with gearing for my own understanding at this point, as to how the scenario happened.
60HP difference on the C4S and the M3 is not going to make up for being in the "wrong" gear. See my response to BMW-M-Mexico below.
Re: limiter - Neither did I, but when it nudged over 270 a week or two ago, it nagged at me...like, "Hey, the limiter should have kicked in just there." I did not have more space, and the engine was almost 1000km newer, so I put it in the garage and figured I would find out the top end for sure soon enough. Haven't found it yet. Autobahn from Oberbayern into Munich is three lanes, but it did not free up properly (and a debadged Audi would not get out of the damn way until Holzkirchen (like it was a contest or something...beat those squirrels! faster! faster!)) Three M3s in a row, and a tailgating Italian in an S Klasse Mercedes that showed up late to the party and in a hurry every time we were slowed down.* Fun run.
Carrera 4S. I tried him first in 5th, and outran him barely after I got to 6th. Dropped it to 4th for the next one. Pulled away more clearly. Then we both eased up and cruised.
*it was Italy v- Holland last night, so I can understand. The Biergartens, cafés, and bars are packed for the European Championship.