Sorry bud.
Try this site;
http://www.fastestlaps.com/car47d9a014adba0.html
I do think that is conservative... They are "official figures"
I do have to say though, when wheels compared the then-new HSV GTS with the NUR R34, the 34 put out over 220awkw on a 36 degree day, while the 300kw GTS put out around 210rwkw on that day. (If memory serves me).