How do you do the new one? The one that gives you the level 23 ticket?
Make sure you stay in the 1:35 zone and do not cut the corkscrew. I noticed that my lap times are better if I don't cut the corkscrew. I used the mid turbo and also added 10 extra kg(1260) with the ballast max to the front. It seems to help with the cornering. The first two challenges are relatively easy.