it was hard to track down the specs, (i guess i just don't knwo where to look) but i saw that not only did the CSL lose 160 or so lbs. actually according to topgear, its 95kg, thus over 200lbs lighter, and also did get 7 more horses to 350 over the euro M3, which has 343. add the other go fast at the track goodies, and no wonder CSL gets much better track time! oh and the price tag too.. there are so many factors involved in making a car get the fastest track time that it really is hard to single out one factor, saying that's it! cardboard trunk floor only gets you so far..
as for the horsepower deal. i could see why people talk about BMW horses are different. it is not that BMW has "special horses", rather the fact that they are very conservative about their figures. its just that everyone talks about what the manufacs put out as their specs. they don't really list the horsepower @ the wheel. (which is what really counts) that's prolly why the zhp can make up the whopping 43 horse power difference, (sure you can bring up the weight thing here too, but i think there's more than meets the eye.) i wonder what the hp @ the wheel numbers are for stock G35, TL, 330, etc. rather than what we see on the brochure.