I was thinking the same thing during my race last night. I don't know when it started, but the rear end of the Cayman, especially, has seemed much more likely to lose traction than I remember earlier in the year. I didn't notice it with the BoP adjustment, so not sure it was then, if anything changed, but for sure, the car is not as predictable as it was in the earlier rounds, or at least it seems. Something seems different.
I lost what chance I had to make up any spot on the run up to the green flag, by losing the rear end out of the last turn at yesterday's Ring race... it just stepped out under throttle. For a car that isn't exactly high on HP, it seems odd. And I'm with you... just can't find the handle on it lately. I'm pushing like hell and still watching everyone walk away from me, I just don't get it. I have no chance on the power straights, and I'm not able to keep my cornering speeds higher than others.
What I really don't understand is that I see others winning poles and races with the car. Discouraging to me, as I normally feel like I'm consistent, especially in Gr4, where my K' Speed Score is effectively 80. So getting trounced at the Ring yesterday, and being unable to find the speed has me scratching my head.
Meanwhile, without any prior practice, I was able to take a Vette from 6th to 3rd in my alt account race, despite not driving that car much, in a lobby that was similar to what I raced in for the first half of the season (including some of the same racers). So it seems I just lost the handle on the Porsche...
I think you just need to go ahead and make the switch to Chevy