My best bet are two things:
- start: auto clutch, pedals wrong, auto-blip, traction control or even stability control are slowing you down. Or purely reaction time but that I doubt if you're able to drive with your real Cayman safely around a real track.
- corner exits: you're just a noob, as 99% of people are. I thought I was pretty fast back then, got last in my first club race here... Now I get mostly into top 10 without even practicing (because I practiced effectively on my general driving errors for a year and we have 30min practice and 30min qualy before the races).
To dismiss technical problems, please take a Kunos car to the 2000m drag strip and tell us your time (do a race so you start with the start lights etc).
We will then do the same and we will be able to get closer to a solution
Better way would be to record a video. Replay + smartphone camera would be enough!
But I get if that might be too complicated for now!
PS: with "noob" I don't mean to insult or anything. Especially if you have real track experience I imagine it to be very difficult to adjust to a simulator. While you're probably quite fast and very safe in real life, pushing a car in a simulator is like endangering your life in the real thing. You just don't drive like that in the real world. At least not if you're not a professional!
Also when you're at the limit of being safe in real life, you are probably still a few seconds off from simulator times. No real forces, no real fear. A kid that won't be able to even drive around safely at a trackday might beat us by a second in the sim because he learnt how to do it, runs low FFB and just practiced for weeks.
It takes time, patience and some good advice every now and then to really get fast