Turbo LY R27
172 cup = 168bhp/ton (1021kg)
197 R27 = 161bhp/ton (1240kg)
plus weve got to remember that r27's arent making 197bhp, whereas alot of 172 cups are hitting 175 bhp, which would skew those figures a bit more.
Mate the 197s do hit the figure and sometimes a sneaky bhp more, search the forums mate. And its a well known fact that most 172/182s DONT make the figure.
You can think what you want mate, you and me at silverstone, you wouldnt stand a chance.