If I only changed the rear sway bar ....

[LAP1DOUG]

Personally I think this falls under the category of "unsticking" the end that is working well in order to achieve balance, which Carroll Smith taught us is not the best approach.

To me this seems like a particularly bad approach on a McPherson strut design with an open diff. The stiffer rear bar transfers more weight in the rear, which unloads the inside rear and wastes torque coming off a turn.

The front end on any Boxster (986 or 987) clearly does not have enough camber for maximum performance even at the maximum adjustment, and the inherently poor camber curves in roll with a McStrut design makes this even worse.

I believe that a slightly stiffer front bar is the best low cost remedy in order to limit front roll which would otherwise cause positive camber in this design. This will make the front end stick better rather than unsticking the rear. Caution though: it is a delicate balance - if you go stiffer than the minimum needed to tame the camber gain in roll, then you will cause more understeer, rather than less.

Ultimately you really need camber plates or GT3 arms to make these things work right.