How to make long-running races with cars that do not allow refueling?

I wanted to do an endurance race but wanted to race with a Classic Cup car. The problem is that it is not possible to supply them. Is there any option to enable refueling for these models?

Thanks!

 

I believe that if you use All Cars and Tracks instead of selecting a specific series, it'll run without any series-specific rules, including refueling limits. Not 100% sure on that, but I'm pretty confident that's true.

 

Either use all cars & tracks or create a custom srs file that allows refueling.

 

This thread has just been useful to me , so I would like to add something that is not here:

To create a srs for this will need to look for the section bellow and change (or add) "RaceRefuelling" to "1", like this example:

...
DefaultScoring
{


// SESSION TIMES AND DURATIONS
RaceRefuelling = 1
...