Use the default suspension settings, set top speed to 300km/h, gearbox as follows:
1st:2.863
2nd:2.021
3rd:1.545
4th:1.338
Default diff settings except for deceleration, make that 5 instead.
Front aero 475
Rear aero 465
This works for me so well. I can run the whole lap flat out if I take the correct line. The crucial factor is turning in at the correct point. Get it right & you'll be turning out laps with no drama. Get it wrong & you in the wall fella! It's simply a matter of gettin to front & pulling away. Concerntrate on doing turn 1 & 2 properly on Lap 2. Don't let the AI draft you & remember these Nascar boys play rough! Rubbins racin as they say :-)
Hope this helps
Pete