Dean29, I have not got the 'exact' numbers you're after but I believe that the BoxsterS is faster than the S2000 in particluar at higher speeds. BoxsterS has 6 speed gearbox as closely spaced as the S2000 and a power curve that is a lot fatter. Also, BoxsterS had a lot better drag coefficient than the S2000 (which has actually pretty bad drag coefficient).

Above 200kph the BoxsterS is a fair bit quicker than the S2000 but up to there it's close.

Here's some numbers that I could dig up:
S2000 vs BoxsterS
0-100hph = 5.9 vs 5.9
0-200kph = 24.4 vs 23.4

That means that:
100 - 200kph = 18.5 vs 17.5 (which is close to the range you're asking about).

1km (standing start) = 25.8 vs 25.6

Also, around Nurburgring, they both leave the Galkenkopf curve at 126kph and towards the end of the straight the S2000 was clocked at 226kph and BoxtserS at 234hph. That is also very close to the 'range' your asking about.

 

See my topic S2000 v 928GTS.

No problem with a Boxster S, only problem was that he would'nt move over, he certainly could gain on me.