Hey, congrats on your new car!
I have an '18 that is setup for CAM-C and I live in Lafayette. I attend many of the SCCA and BMW club autox races. This weekend there is both a BMW and a SCCA race, BMW at Front Range Airport / CASP and SCCA is at PPIR in Fountain. I'm torn between the two but will probably go BMW because it's much closer and attendance will be low since there's also a SCCA event, so we'll likely get a ton of runs in. PPIR is a nice venue but does have some concrete walls. Also BMW course design is better imo. PCA comes up with some weird ones... Sign-up ends tomorrow, you need to be a BMW club member but it's only $50 or so.
https://rmcbmwcca.com/events/ax2022-5/
Anyways, a few things to do off the bat that I'd recommend:
- PPF, sideskirts and rock guards. I used a lot of PPF, but it's critical in front of the rear wheels. ACS makes some decent sideskirts and rock guards. IMO they really should've come with our cars. The skirts massively reduced rocks hitting the side of the car, I actually replaced some PPF after one year before I got the skirts it was so bad.
- Brake Fluid... I use Brembo HTC64 I believe. I got a pressure bleeder and use it dry to push fluid through the system, works fine. Brakes have two bleed ports, so I got two catch bottles.
- ZL1 1LE rear cradle bushings. Improves feel and handling in some circumstances, but feel is far better in exchange for a small increase in NVH, but it's a welcome one as it makes the car feel more connected and less isolated.
- Vorshlag camber plates. Maybe not right off the bat, but the oem track settings are not nearly enough for autox. I get far more even tire wear and much better grip and predictability with more camber. The plates also increase NVH similar to the cradle bushings, you can feel the road a lot better and it adds a lot of feel via the steering wheel, again a big improvement in how connected the car feels. Almost forgot, for the rear end get some SPL toe arms with lockouts, it'll maintain alignment better and allow you to dial in more rear camber.
Roll bars and GMPP autox ediff tune add a lot to the car's capabilities but the car is great as-is, these two things make for some pretty large changes, I wouldn't do them until you get a feel for the car. Although the ediff tune only works in track mode with all nannies off, so if you're using PTM modes on track it won't be active, but you really need autox tires, alignment and roll bars for the diff tune to work as intended.