Yeah, just a little bit of downforce, like 20/20 or 50/50 (kind of like the Shelby Daytona) would make a huge difference.
I think I've got it fairly sorted out:
Set ballast to 100 (close to a true 50:50) I find these old cars with no downforce like a balanced tune to avoid the "pendulum" braking, etc.
Suspension:
98 100
7 7
28 28
42 42
2.30 2.30
2.0 2.0
\/0.20 /\0.20
LSD: 25/45/22
Transmission Gearing: Set Top speed to 340 (standard, I believe) I set the gearing in intervals of .005 to make it easier to read.
1) 3.785
2) 2.765
3) 2.160
4) 1.755
5) 1.480
6) 1.300
Final Gear set to 3.075 for Sarthe. It's a little stiff, but is much more stable. Takes a couple laps to get used to, and definitely trail-brake into curved brake-zones (like the end of the Mulsanne at Sarthe, etc) as it'll re-stabilize it if it starts to get loose. Use the recommended gear when cornering (might be a problem with my gear ratios; I haven't fine-tuned yet)
I was able to put up a 4:02 on a PS4 controller (haven't tried it on G29/PS5 yet) in TT, which is pretty good for an old F1 with no downforce on a controller (for me at least, lol)
Hope this helps someone.
Edit: Forgot to mention this is with Race Hards and High RPM Turbo. Brake bias is neutral to save tires, but I tried it at both +1 and -1 and still seemed fine. Kind of prefer it towards the back. Should be about 667PP, so plenty of room to add Mediums or Softs if one so chooses. And yeah, I don't like expoiting the ride-height for stability, but when we aren't given any downforce it just makes sense given it's so much more stable.