Having quite an awesome go with physics, learning a lot of things, really love rF2 and how physics are, physics are more complex, everything is just more, but I also find them more intuitive to work on, and more flexible.
Big big thanks for
@Bumble for best feedback that could be made. I still have to install Motec and the plugin and go through the data, that is incredible to me.
I have made a jump into a geometry and suspension world lately, turns out it is not so impossible to understand. The challenging thing is accuracy and having it correct. Thanks to beautiful Leonardos physics modding tool I was able to visualize my changes, and how they affects camber gain/toe gain I could get pretty awesome results. As for anti-dive, anti-squat, and F/R anti roll geometrical stiffness, they are very approximate now, but feels great, perhaps have too little anti dive as fronts seems to lock a bit easily under braking in some times. Also in a special places car feels like it suddenly turns in harder, this happened in Oulton Hairpin mid turn, then I realized that I had too much rear wheels bumpsteer, thanks to Leonardos tool could made it to be very minimal. Later in Miseluk I had similar problem in a place where you enter a highway in fast narrow right hander, it is like if inside wheels had more traction at very instant moment under great compression. So it is interesting to work on those things. I also found it interesting who easily I could modify mechanical trail, I can easily make FFB to "fall-in" when car understeer (the effect that everyone freaks out about, but still I see people asking for understeer sliders in FFB options of the simulators), I can adjust steering to be more pneumatic trail sensitive, adjust scrub radius... so much things...
Right now my geometry is not something in particularly great, I have to do some drawings to know precisely where all the centers are, how big are all the moment arms, how the forces travel through the chassis that makes it do things that it does. Also have to watch a lot of YT videos lol, and have a lot of reading. My values are now quite low decimal accuracy and yet to be tweaked, I see original values in the base PM which I use are like 5-6 digits decimal accuracy lol thats insane who would ever have this crazy manufacturing accuracy for whole chassis IRL ?

And in 60s.
The car pretty much uses front suspension of an E-Type. Rear end is more complex.
Thanks to Building The Legend project, this car mod was made possible. Building the legend is making the replica of Jaguar XJ13 in original 1966 specs.
Thanks to it I could see beautiful things like this:
It definitely helps for me. I am also able to use 3D modeling to locate the points more accurately and reduce the guesswork. Still tweaks are necessary to make things to function as they should.
By the way, one more interesting thing. I have found that historic racers these days are slightly faster, so if I aimed for reference best laptime at Goodwood to be 1'21 before. Now I have it lifted to 1'22-1'23. Still wondering maybe I should lower it slightly again, since car uses after crash setup - wider tires, for example. Late sixties cars seems to be less faster than they were in their time, and 50s cars such as Dtypes seems to be more faster, like they were ~1'33-1'36 originally, but in GW revival sub 1'28 has been done. However, Ferrari 250 GTO best laptimes in Revival and in 1964 are matching. Jim Clark did 1'20'8 with Lotus-Ford 30, Lola T70 was still in early stage though, but in this era sub 1'18 has been done...
By the way, I am also very interested in 50s cars, and working on Woochoos 1954 Endurance mod, to make physics sharper on the subject. Currently was spending quite a lot of time on that too.