Spa alternative? Change spawnpoint and start boxes?

[destinationriver]

Cheers, as the 2017 24hrs Spa have been on this weekend, I wondered if there is a version of Spa out with the other pitlane used (just before Eau Rouge). I haven't found anything, so I wondered if it is possible to change the spawn point manually in the other pitlane. It already detects your car in there, so when you drive in from the track, the pit limiter will be activated.
Can anybody help me out with that?

 

[Matyeah]

Can be done as a new layout, without modifying original files. I imagine s/f line would also have to be moved?

 

[destinationriver]

Well, I don't know anything about modding tracks. Would be cool as new layout, basically its just changing the start points. And needs a new AI I think then? Whats the s/f line?

 

[Matyeah]

Start/finish line! If only pits are moved then only pit lane ai needs changing. If s/f line is moved then fast_lane.ai would need to be done as well.