Brake and tire upgrade?

[bmwzzzz]

Hey all,
I've been loving my Z4 lately. I've got plenty of mountain roads I've enjoyed lately.
The Z4 seems to come with large drilled rotors in the front with more standard flat rotors in the rear; I'd like to gauge the community if they are sufficient for longer sessions.

Sonoma Raceway is nearby and has track days open to the public. This is something I may do once or twice but would be surreal to experience this car in its unlimited state.

At the moment, I believe my car has the stock brakes (large drilled front rotors and standard rear rotors), along with a pair of Vogue 17" tires all around. I've definitely felt the edge of the tires going around some fun corners but I feel this car can stick way more.

If anyone has experience setting the car up with the aspect with the majority of time spent daily driving while having the ability to let the car loose on the side, I'd love to hear their setup.

Engine upgrades feel risky for reliability, but brake and tire upgrades feel like a perfect way to turn this roadster into a monster.

 

[smorris_12]

Drilled discs aren't standard, someone has put them on aftermarket. Nominally the holes deal with heat dissipation better but can present stress risers that can lead to cracking.

Brake upgrades come in two aspects: more power and more cooling. The former can be achieved with higher performance pads or a large disc conversion from a 3.0si but these are only worthwhile if you have super-sticky tyres. If you can already brake hard enough to break traction and trigger the ABS then they're as powerful as they need be. If you upgrade to high end tyres (or track oriented racing slicks!) and you reach a point where you can't lock them up then you need better brakes.

The other aspect is cooling. Driving hard, particularly on a track, can cook the pads/brake fluid to the point where they fade and you're doing 100mph towards a tyre wall with no stopping capability. Fresh fluid with no moisture in is essential. What's really needed is ductwork to direct cool air onto the brakes. I don't know if the Z4M had anything in this direction that could be upgraded to; some of the track oriented M3s did IIRC (think the fog lights became the air intakes.)