Week 51 Daily A: Daytona International Speedway GR.3

Somehow i got a 00:45.897 with the Ferrari and i think that is that what i can get on a controller

If you can, try to find a top replay with the ferrari to anlyse with the data logger, you'll be able to see the exact setup outside of gear ratios. Then, I'd suggest watching the lines used by the top replays, there are a few subtleties that gain a lot more than they seem, and only by comparing myself to the logger I've been able to notice them.
If you can't find a replay to get a setup for the ferrari, you want the car as low as possible, minimum aero, power as close to the limit as possible (don't forget to buy a restrictor, you can get closer by mixing ECU and restrictor). For the suspensions, you also want no pinch angle (wheels straight, idk how it's called in english), and as much camber as possible (to get more grip in the banking). The mustang setup also has minimum frequency and roll bars, not sure why it's faster but maybe someone more knowledgeable on physics could help. Finally, differential is set on 30-60-20, so halfway-max-third if the max value isn't the same on the ferrari. 
The setup should feel understeery, and I find a bit of disconnect between my input and the car's steering, but I'm on controller so it might not be noticeable on a wheel. From what I've seen in Super GT's video, the ferrari is a lot more sensible to getting on the yellow line so you'll need to be careful no to touch it if you want to race. If you're hunting a time, you'll want to almost graze it.