As I've been tagged by @Grblue86, I'll throw in my 2 pence.
Hi All, potentially looking at taking the GR86 on track sometime next year - just wondered if any forum members have any feedback / gotchas to be aware of in advance?
E.g., How do the standard brakes hold up?, any recommended tyre pressures? Did your tyres hold up OK?
Track Day advice:
Depending on your track knowledge/experience level, adjust as appropriate
Warm the car up slowly for a couple of laps, i.e. don't go out and buzz it off the limiter immediately.
Start the day off in normal mode, get use to the balance of the car, i.e. get a feeling for the grip level, brake pedal feel, when the traction control kicks in, etc
Check the oil temp during the session (I can't remember if this only shows up in track mode) - Anywhere between 80°c-115°c is good, 120°c getting close to the limit, think about taking it easy, 125°c time to back off.
Do a 15 minutes session
Cool the car down, for a minimum of 1 full lap (if your at a short circuit, Brands Indy, Blyton, Mallory, do atleast 2 laps)
Check your tire pressures throughout the day, try to aim between 30-32psi hot. (This is massively weather / condition dependant, 30-32 psi is normally a safe bet on PS4's)
Once your happy/confident turn on track mode.
Book tuition. - I've been doing trackdays for 10 years now, I still get tuition from time to time.
Most importantly have fun. 
Also consider buying trackday insurance, its a relatively rare and expensive car and at £150~ for some piece of mind goes a long way. Track insurance doesn't cover mechanical breakdowns though, only accidental (get hit by another car, crash into a tyre wall, etc)
Car setup:
Out of the box, the GR86 is fairly well setup for basic/limited/beginner track use. There are a few things I'd change before heading out on track though.
1. Good tyres - OE Michelin PS4's are fine, just make sure they are in good condition, i.e. not down to 2mm tread. You don't need trackday tyres (semi-slicks), unless you want a spare dedicated track setup.
2. A set of track capable brake pads. A good, cheap and readily available option are EBC Bluestuff
Front:
https://ebcbrakesdirect.com/ebc-bluestuff-race-brake-pads-dp51884ndx
Rear:
https://ebcbrakesdirect.com/ebc-bluestuff-race-brake-pad-set-dp51584ndx
Lots of other choice available, take a look in the brake upgrade guide:
https://www.gr-zoo.com/threads/gr86-brake-upgrade-guide.1507/
3. A high quality brake fluid. I personally use Millers Race 300, another option is Motul RBF600
Those are the "essentials", once you've done the above then I'd start looking to add some camber to the front suspension, either via fixed/adjustable top mounts, camber bolts or coilovers.
Oil weight/overfill is an option, although its not something we've done on my brothers car and thats done a few days this year.
Oil cooler could probably be the next option after that, although that starts to get into a grey area with engine warranty.
BBK isn't a requirement, but a good option if you start doing half a dozen or so days a year.
Or you could consider it a requirement if you find the OE brake calipers visibly challenging - Why Toyota didn't you offer us Brembo's as a option?
Hope that helps.
Here's a couple of photos of my brothers GR at a recent trackday:




