Try this tune:
1. Aerodynamics: 70, 90
Transmission: 242
LSD: 15, 40, 45
Suspension
Ride Height: -6, -4
Spring Rate: 17.6, 17.3
Dampers Ext: 8, 8
Dampers Comp: 6, 6
Anti-Roll Bar: 7, 7
Wheel Alignment
Camber Angle: 2.0, 1.0
Toe Angle: -0.30, -0.20
Brake Balance: 4, 1
Driving Assists *Note*These are more or less crucial to this tuning being worthwhile, although your preferences may be slightly different
Transmission: Auto <---This lets you concentrate purely on your driving line and avoids red-lining due to human error
Tires: Racing Soft
Traction Control: 8 <---Let's you hammer the gas hard at any time, but still accelerate fast enough
Skid Recovery Force: On <---Helps keep skidding in check obviously
Active Steering: Mild <---This is critical. Because the AI turns so sharply, I gave the car's tuning some adjustments towards oversteer. This does let you turn sharp enough to beat the AI, but you need Mild Active Steering to keep the car stable and easy to drive. I wouldn't go to the Strong setting, however, it'll more or less cause you to understeer and make the whole thing pointless.
ABS: 4 <---Gives you a bit of oversteer when you smash the brakes, but not enough to actually spin you out.
Take advantage of the stability you'll have due to all the assists and you should be able to slam that thing around pretty fast once you get used to it. Also, figure out braking, because you can break shockingly late with this setup and have total control. I found that I could use the transmission setting of 242 to always catch up a bit in the straights, then brake late into the turns to pass.
Also, I found that the aforementioned oversteer caused by heaving braking can be used to your advantage. With that Mild Active Steering and ABS, you're so stable that you can basically skid into a corner and wind up facing exactly where you want to much easier than normal. This takes some getting used to though, so be warned.
That is not my tune but cheers to whoever made it. It worked wonders.