Considering only non Group C cars, and true paces, we've got this:
1 - Peugeot 908 HDI FAP '10 --------------- [3'19'074] - LMP1
2 - Toyota TS030 Hybrid '12 --------------- [3'24'842] - LMP1-H
3 - Audi R18 TDI '11 ------------------------ [3'25'289] - LMP1
4 - Toyota TS020 GT-One '99 -------------- [3'29'930] - LMGTP
5 - Audi R10 TDI '06 ------------------------ [3'30'466] - LMP1
6 - BMW V12 LMR '99 ----------------------- [3'31'209] - LMP
7 - Audi R8 '01 ------------------------------ [3'32'429] - LMP900
8 - Bentley Speed 8 '03 -------------------- [3'32'843] - LMGTP
9 - Pescarolo Courage C60 Judd '04 ------- [3'34'252] - LMP1
10 - Pescarolo C60 Judd Hybride '05 ------ [3'34'715] - LMP1
11 - Nissan GT-R LM '15 -------------------- [3'35'888] - LMP1-H
12 - Mercedes CLK LM '98 ------------------ [3'36'901] - GT1
13 - Audi R8 Team Oreca '05 -------------- [3'38'281] - LMP1
14 - Zytek Z11SN Greaves '13 ------------ [3'40'100] - LMP2
15 - Nissan R390 GT1 '98 ------------------ [3'40'649] - GT1
16 - Panoz Esperante GTR 1 '98 ----------- [3'40'730] - GT1
17 - Pescarolo Courage C60 Peugeot '03 -- [3'40'839] - LMP900
18 - McLaren BMW F1 GTR '97 ------------- [3'45'402] - GT1
But almost everything is wrong ingame, with the '05 Pescarolo and Audi R8 '01 as fastest cars. For me, only few cars are well balanced, like the Peugeot 908, or the Toyota TS030.