This is a complete cheater build and isn't really a driveable car either. I modified the lua file to stretch the frame so i could fit a bigger engine in. I believe it is a 5 liter TT v8 w/ around 1800hp. I set engine airflow and brake airflow to 0 to achieve the top speed.
I did get the Lotus 7/Donkervoort looking car from the Steam Workshop around the track in 1:40 also without me needing to modifying the lua files. I'll post that one later (still has insufficient cooling to get it done)