I found the plot I got off rips years ago, correlated well to all my cars for whp Vs mph over line
If the cossie is 1500 kg with my arse in it then at 650 whp I should hit 137 mph crossing the line
Supra was 1700 kg with me in it and when I got it right hit 134 mph which is 700 whp on that plot, which is about right imo as supra made 757 at the hubs, would of been a good bit less at the tyres