You might want to reconsider some of your childish opinions, the '04 Pescarolo isn't fast just because Polyphony saw fit to, in '04 it genuinely was the nearest competitor to the Audi R8's on raw pace along with the Dome S101, unless you mean the lacklustre '03 car which suffered from a rubbish engine.
Do not be surprised with your top two, they may be down on power but they've got the legs on the Group C cars in the corners in real life and in the game. If you don't believe me, refer to the grid positions of the cars at Le Mans when they competed here:
http://www.racingsportscars.com/photo_lemans.html
The real inaccuracies on here are:
The performance of the R92CP, this is an unknown at Le Mans because it never raced there, it stayed in the JSPC due to the ACO's antics changing the rules to benifit Peugeot(i.e. = cutting places for the C1 category). Although I do think it is the R90CP mis-labeled, in which case it would be on par with the Sauber, if not quicker as it beat the Sauber to pole one year.
Also I think you must be one of those who think Mazda's victory in 1991 was a big fluke, because that's a car which had pace on par with the Saubers, Jaguars and Peugeots that year.
The performance of the Bentley Speed 8 should be either on par with or quicker than the Audi R8 and the '04 Pescarolo, let's not forget that it WON the Le Mans 24hrs BEATING the R8 in its prime.
Your right, the Peugeot 905 should be the fastest here because during its active years, along with the Sauber C11(not the C9) & C291, Jaguar XJ-R 14 & Toyota TS010 where FASTER THAN F1 in it's prime, so its definately the fastest.
The reason why the Sauber C9 was hyped up was because it was the fastest car outright when it won at Le Mans (lap time pace, long run pace and speed trap), It clocked the fastest speed ever clocked during the race one year (don't get confused with the WM's 250+mph record in qualifying).
There is also no way in HELL the Minolta 89CV(it is actually the 89 car) should be that quick, it was completely useless at Le Mans, even the C2 class cars were quicker!
Sorry I had to correct your opinions in relation to the real life and game performances of the cars but I find that the way you opinionated your write up was quite narrow minded and almost fanboy-esque, come now, accusing Polyphony of tailoring the performance of the cars to their liking? Thats something I'd expect from a Forza fanboy on youtube, suggestions and opinions like this I find purely ridiculous as someone who's been to Le Mans every year since the age of 6.
But, I admire your thinking in pulling off an experiment like this, hopefully you'll do an ammended one for GT5
use the link I've given to look into the relative performances of the cars at Le Mans.