Yes you can create a default setup for AI to use per car, per track. This is quite easy to do, but can be time consuming. This is how I always done it:
Load a test session/race weekend on any track you are wanting to make a setup for with the car you want to make the setup for. Tweak the setup to your desired performance by the AI, then save this setup. Name it something easily recognized as your AI setup, something like AI-Settingxxxxxx
Go to the settings folder for the track in UserData\YOUR PROFILE\Settings\xxxxxx folder, and find the setup you created for the AI.
You then will place this setup into the car's folder, \GameData\Vehicles\EnduranceSeries\xxxx\xxxxx, by either moving (if you made this setup JUST for the AI) or copy/paste if you wish to keep the setup for your use or further tweaking.
Go into the locations folder and find the track you made the setup for, and load it's GDB file. At the bottom you will see an entry for SettingsAI =. This is what you should rename the setup file you just placed in the vehicle's folder to, and that's it.
Lets use an example. Lets use the Corvette C6.R for our car, and VLM's Le Mans 79-85 for our track.
-Load a session with any Corvette on the track, create a setup and we save it as AI-Corvette-LeMans 79.
-We go to the UserData\YOUR PROFILE\Settings\VLM_LeMans_7985 folder and find our setup, AI-Corvette-LeMans 79.svm.
-We either copy or move this file to the cars folder in gamedata, our case is \GameData\Vehicles\EnduranceSeries\GT1\Corvette_C6R
-We then go to the tracks folder and load it's GDB file with notepad. Our case this is found at \GameData\Locations\Virtua_LM_LeMans\LeMans_1979. At the bottom we will see :SettingsAI = VLM_LeMans_7985.svm, therefore we now know the proper name to use for our AI setup to work correctly.
-Go back to the Corvette C6.R folder and rename your setup from AI-Corvette-LeMans 79.svm TO VLM_LeMans_7985.svm.
So now when you load a race versus the AI on this track, now all the cars that are under the Corvette C6.R folder should be using your setup. This will have to be done for every car in the mod, just the base model - not each skin, separately and for each track you wish to make a setup for.
Hopefully this helps. It's quite easy to do just not so easy to explain. If anything confuses you don't be afraid to ask for further explaination.