bullsh!t.. especially with the N55's. N54's with meth and downpipes, not even my z4 35is came close from a acceleration perspective with the M5.. take his pink slip with launch control or throw a few corners into it and you won't even see him behind you.
http://burgertuning.com/N55_Stage2_Jb4.html
btw.. Terry's beta tune just came out for the N63/S63.