Yeah as Chris said the 197 is not massively fast in a straight line, I don't even entertain people who want to 'race' on a straight road. Happily have fun with people on some twisty B roads though.
I have always been pleasantly suprised by the cars i have taken on the straights (track..obviously). From bmw 120's to a heavily modified golf gti and mercedes C class (non AMG, of course). Maybe have yours put on a dyno, usually only about 40 quid for a few runs with printout.
My old 1.6 mk1 Eunos would happy sit behind a friends ph1 172 up to 70mph. Both cars were dyno'd at a ClioSport day that day and made 115bhp and 160bhp. It's purely down to weight and aerodynamics.