My gut feel is tyre pressure.. Sounds like you are running too low.. I know Tim Woo in the ISF was seriously chunking fronts on his..

Couple of things..

How far on the outside of the tyre is chunking ?
Whats brand, model of tyre ?

I am a big fan of “tuning the nut behind the wheel” before looking at the car, but the tyre pressure is pretty critical. I spent a whole year wondering why I was 1 second slower than cars of identical spec. I was over driving the car, trying to find that extra time. Hitting the right tyre pressure and getting the same rubber as the equivalent cars made a lot of difference. Still had to lift my driving game, but the car felt more drivable. Particularly less understeer which is the killer.

I wouldn’t fuss too much with tyre pressure, but make sure you get a setting that maximizes the car and then you have a stable platform to hone your skills. Either use the chalk or talk to somebody with the equivalent car.

Sounds like you are up for some new tyres, so get some feedback from this group on a good tyre. I run a RE11 on a e46 M3 with 19″ rims, but your is a little heavier and might have some other tyre options.

B