After setting the downforce to about 40% of its default value front and rear, and adjusting the gear ratios and final drive to give me an indicated 200 MPH top speed, I took this car out on the Daytona oval in practice mode.
The car behaved very oddly. It would not get beyond 185 or so on the straights, and the moment you entered a corner the speeds dropped drastically, down to about 135 by the end of the corner - this would even trigger a yellow flag. I listened and checked the rear view to see if I was bottoming out which could possibly explain this, but no audio scraping noises or spark images were noted.
IRL these cars should hit 220 on the straights and be doing 190 in the corners at Daytona IIRC. I'll try taking out virtually all downforce but I doubt that is going to fix the cornering issue UPDATE: bottoming out downforce values gives better top speed but does not solve the cornering slowdowns - it's acting as if the fuel is cut off. Raised ride height a few inches and no better.