Here's the statistics from Famine's database:
LMS
Car Power Weight PWR
Audi: R8 ’01, 599 900 665.5
Audi: R8 ’05, 579 950 609.5
Audi: R10 TDI '06 649 925 701.6
Bentley: Speed 8 ‘03 623 900 692.2
BMW: V12 LMR ‘99 571 900 634.4
Peaugot: 905 Race car '92, 512 750 682.7
Peaugot: 908 HDI FAP Team Total '10 700 930 752.7
Peaugot: 908 HDI FAP Team Matmut '10 700 930 752.7
Pescarolo: C60 Peaugot Race car '03 519
Pescarolo: Courage-Judd GV5 '04 592
Pescarolo: C60 Hybride-Judd '05 637
Toyota: GT-one '99 599 900 665.6
Group C
Toyota 88CV 'Minolta' 902 850 1061
Nissan R92CP
Nissan R89 788 900 875.6
Sauber C9 Mercedes 710 893 795.1
Jaguar XJ9 749 894 837.8
Mazda 787B 690 930 741.9
The Data for the Minolta is from mine as I couldn't find it in the database. The R92CP isn't there either so it would be great if someone could provide them. Also there wasn't any weight figures for the Pescarolo's and I'm unsure if they're available in game. It's up to lb1990 to balance the field so hope this info helps.