Hi , sorry for this. Lot of job, i enter the forum 20 minutes a day only , no time for nothing ..... About the Pescarolo, i remember that i did my best to control this "slipping problems".
The only thing i can tell you to try to let the car better without driving it, is:
Set a very low LSD value , initial and accel,for the moment on my tune it's 12/10/25. Try a 5/5/25 and raise the accel value first (second one) if you see the inside rear tire spin excessively (red) i think a 5/8/25 or 7/7/25 can be ok.
I can't say you to do something else like dampers or else because i'm not able to drive myself. Too bad, hope i'll play in a few months.
You can also set longer 1 & 2 gears and shorter 3,4,5,6. It must help too.
I think this car need a mini tuner shootout. So much good people around here , somebody can find the solution. For sure , i'm not very proud of my tune, but i don't know other better till now.
Very hard car to tune.

Good luck and good night everybody.