I’ll ask here since it’s the most recent thread on the topic. What is it about this chassis that makes a stiffer front bar counteract under steer? With other cars I’ve worked on, and every bit of literature I’ve referenced, increasing rear stiffness increases oversteer, as does softening the front bar.

I’ve got a street-driven G37 coupe, and can’t figure out how to pick a sway bar upgrade. On previous projects, it’s been a no-brainer.

The front of our car is too soft in stock form

Too soft can result in less grip, just like too stiff.

As for what to pick, you could spend hours on theoretical sway bar effects. Or you can just try what track drivers with this chassis have done and run the stiffest bar available

If you find it does not suit you, just change get it. It’s a sway bar, it’s not a permanent move

The general concept of “softer end has more grip” is a broad generalization. If you had super soft rear springs for example, more weight would be transferred to the rear wheels, and is why Gran Turismo teaches people that this increase rear grip.
But in real life overly soft rear end that transfer too much weight too quickly to that end will lead to a loss of control just as an overly stiff rear spring would that prevents weigh transfer

It’s about reaching a certain baseline of stiffness, it just …being stiff or soft generally