I tested rapidly the Porsche RSR yesterday on Montreal.
Aside my "taxi driver" level skills, I found it quite difficult to handle: understeer in some turns (for example the first left turn after starting line) and spin if I decrease gear with too high RPM.

Is there some setup parameters I can work on or I must learn to drive?

Hi Steve,

I'm not a 911 maniac either, but it requires a different driving style than a front-engine RWD car.
The biggest problem on downshifting should occur when you change from 3rd to 2nd. It's crucial to watch the rpm there and that you're not downshifting to soon.
First corner in Montreal is more difficult than it looks - if this is the only corner where you have severe problems regarding understeer, just slow down the speed on corner entry.
Basics in handling the 911 are crucial before you think about setup changes otherwise it gets you nowhere.

Cheers