What psi do you use in your TR with 225/50 and 255/50 tires? Manual states 37 all around but I think is a bit high
2.5 bar (36.2 psi) works well for me (rational street driving, reasonable steering effort, even wear across tire width).
Can't recall exactly why I went with a pressure a little lower than the OM spec -- but could've been related to not wearing out the center of the tread area before the edges. Also, the factory might have gone to the higher side of things to reduce the steering effort -- but just a guess...
Have you tried adjusting tire pressures and seeing how it effects the drive? For the 512 TR, manual says 35 PSI for the fronts/ 34 PSI for the rears. When I bought my car, they were all at 30. I really liked how the car handled, so didn't make a change. Drove on them all set to 38 recently and it was a drastic change for the negative. Easier to turn the wheel, but not in a good way to me. Felt like there was play in the wheel instead of a direct response. I'll try the 35/34 settings and see how that feels.
Modern day tires will take modern day pressures. Look at the spec’d pressure for the tires youre running and go from there.
The pressures on here are from my period Michelin fitment guide https://www.longstonetyres.co.uk/classic-car-tyres/ferrari/testarossa.html
