The way I describe the phenomenon is that in Forza games, it's as if every car sends some torque to the front wheels. The way the front wheels
dig in and pull you out of oversteer makes for truly impossible recoveries...and it can
really, really screw with your head if you are accustomed to more realistic drift trajectories. Now that I have a decent PC with a W10 partition, Forza's wonky oversteer control is a leading reason why I'm still not interested. I wouldn't mind the games being forgiving as much if I didn't have to un-learn my driving technique to play.
I'm curious what they may have in store with the physics while they've been doing this "pause" on the franchise.
Today I went in search of understeer...and I couldn't find it. I thought...well lets test some cars that should be prone to understeer
Audi RS2 Avant - Big heavy turbo straight 5 mounted in front of the front wheels. To be fair, I would expect turn in bite and then just miles of plowing. You get it up to speed and it's just ass-out oversteer
VW Corrado - FWD version of the same above and same result
1931 Bentley 8 Liter - This car has 175-width front tires and it's 90 years old. But somehow, it still refuses to push on turn-in. The ass just comes out immediately. I put the widest tires I could on the back and maximized front ARB stiffness. That made it slightly understeery on turn in, but not dramatically so.
VW Notchback - Ok so if the car with the most weight over the front oversteers, maybe the opposite configuration won't. Nope. Still loses its ass on turn in. I have to say the axis of rotation feels different though. It's like the pendulum is flipped around and the center of rotate is at the back...but it still oversteers on turn in.
I feel like it's something inherent with the Forza physics model. It's like the front tires have only parameters for static side-to-side grip levels and momentum/inertia has no effect on how they behave when you turn in. So whether you turn in at 35mph or 150mph you get the same bite from the front end. I think this particularly impacts cars with very fast steering. Inertia clearly acts on the overall physical body of the car though, so once you get that unrealistic amount of turn-in input, the ass just naturally comes around. I've noticed at lower speeds, all of the above cars handle somewhat rationally and it would explain (at least in my eyes) why cars feel so much worse the faster you go. Whenever I have to drive my silly Mosler to get a seasonal speed trap/zone the behavior of that car at high speeds just seems like pure fantasy - it's not especially hard to drive, it just feels so
strange.
All of this would explain why my 996 GT3 is such a bear to drive. It's fast enough to reach speeds where the physics engine kind of comes undone, it's has incredibly fast steering, it has poor aero balance,
and it's rear engined. So I think this is what is happening. At 140mph on the highway, I initiate a slightly steering input (lets say to change lanes) but the steering is very fast so it gives maybe more angle than I really want. Then because the tires don't really lose any horizontal/x-axis grip due to forward inertia, the front end of the car immediately bites and turns in like it's doing 40mph. The inertia of the car almost immediately starts to rotate around those front wheels. Then the rearward bias combined with too little rear downforce exaggerates the motion and the car. Any correction/counter-steer basically pushes the whole carnival ride the other way into an uncontrollable tank slapper. At least that's my theory.