Having not played Forza in the days of Forza 4 my tuning is a little rusty, I was never a big tuner but I could generally build a car which was good for me.
The problem I’m having is tail happy Front Engined RWD, I’m loosing traction whilst cornering, but can’t seem to find the part of the tune that’s causing it.
2 cars which are affected are the BMW Z4 and M235i.
Try tuning it for more grip at the back, if you do this you also get the fun little but of liftoff oversteer which really helps to correct your line through corners, a good tip is to make rear tire pressure a bit lower, the dampers and springs slightly softer at the back and slightly stiffer at the front, and then tune the rest to your personal liking
It might be in the car build. Try adding rear aero kit and increasing downforce if you have not already. Also, increasing the rear tire width will make a big difference. Otherwise, you can try softening the rear springs.
Compared to FM4 some tuning settings have changed. Coming from FM4 I had to experience that too when I started tuning in FM6.
Here’s what I noticed:
Camber has to be set between 0.9 and 1.6 to be effective.
Springs and anti roll bars have to be set softer than in FM4.
the differential settings are working better with lower setting of accel and decel than in the days of FM4.
My cars became always unstable too when I tried to accelerate out of a corner. In my case it has been the diff that values had to be lowered.
If you like post your settings or send them via pm and I’ll have a look into them.
soften the rear of the car. soften the rear spring and roll bar. if it is lift off oversteer going into a corner raise decel on diff. if it is oversteer during braking raise brake bias. good luck