Stock brakes and pads?
If I construct what you’re saying right, I’m hearing you’re braking into a turn. Things are going fine, car is slowing, and then at the end of the braking zone/trail braking, the pedal stays firm but you just have no braking authority even though you keep pushing harder?
My guess is that you’re overheating the pads and experiencing pad fade which can be pretty confusing and even terrifying in the wrong corner entry.
Once you start driving hard, especially with any sort of TC engaged, even sport mode, the car uses the brakes quite a lot, which will keep the average pad temperature higher. The peak pad temperature spikes after a hard braking zone, and when you exceed the temp range, pad coefficient of friction takes a nosedive even if it is fine after a cooling phase
For any sort of track use, you *must* turn TC all the way off. If you start driving hard with sticky tires, you may eventually start overheating brakes even with TC off and need to look at upgrades
Everyone thinks of brake fade in the context of a long slow hill descent dragging the brakes, where they get hot and stay hot and just stop working, or fluid boiling which tends to stay elevated.
But on a circuit track, your brake rotors and pads are constantly heating and cooling through massive temperature swings, and when you hit the limit of your pads, it will rarely be at the beginning of braking (especially when they’ve had a long high speed straightaway to cool down) but will always be midway or towards the end of braking when pads are at their hottest. And also when it’s the scariest.
Step 1 is learn to drive, at least on the track with traction control full off. If you still want some help managing wheel spin, get a stage 1 tune that has Cobb’s timing-only traction control available (dizzy, stratified and many other AP tunes can have it enabled)
Step 2. The stock pads are very good street pads - you won’t find many that are a better compromise, but you may want to consider getting some dedicated brake pads (or a pad/rotor set) for the track, even if it means swapping them out for more livable street pads. It will give you a chance to inspect your brakes and make sure everything is peachy before going to the track.
