Downloaded your set-up and it's pretty good. 350 km/hr works out to 218.75 MPH. In the garage it shows a VMax of 232MPH.
The set-up I use shows 228 MPH in the garage. On the track I get a VMax of 220MPH (alone), w/ a lap-time of 42.607.
I tried running a 50 lap race w/ 33 car grid, and opponents set to 120%. I qualified over 5 secs better than 2nd place, and lapped the field in 12 laps !!!!!!!!
I've tried adjusting the parameters for drafting & tried to get the opponents to go faster, but NOTHING works.
This seems to be a problem w/ the game as I have had this happen w/ all open wheel mods on oval tracks. The only reason I can think of for this is that the game is set-up for road courses & can't handle ovals.
Any thoughts on this would be greatly appreciated.