what are the best brakes to upgrade to?

[NZ_M3]

Don't run the rears with the Alcons - much more balanced that way.

[toofastforyou]

Originally Posted by NZ_M3

Don't run the rears with the Alcons - much more balanced that way.

so run what on the rears then?

[shimmy]

Originally Posted by toofastforyou

so run what on the rears then?

Edam

[NZ_M3]

Originally Posted by lawsy

The Alcon were very good yes, but they were not balanced for the car, giving too much rear bias

This is incorrect if you do the math.

The Alcon is the only aftermarket brake kit out there that I know of that more or less retains the CSL brake bias out of the box. I did the math and it adds up.

See below.

Originally Posted by toofastforyou

so run what on the rears then?

Standard setup with an equivalent brake pad compound as the front Alcons. I am running pagid rs29 on the front alcons and performance friction pfc01 and the brake balance is "perfect" (quote from a veteran champion professional racing driver and acredited bmw driver training instructor who took my car for a test run around a new track yesterday and provided me with some setup feedback)


If you want me to get really technical I can ... but as a reference.

The stock E46 M3 has a front to rear brake bias ratio of 1.98 (i.e. front heavy)
The standard CSL has a front to rear brake bias ratio of 1.73 (i.e. shifted slightly to the rear compared to the stock M3)
The standard Alcon kit in both front and rear configuration has a front to rear brake bias ratio of 1.78 (i.e very close to the stock CSL setup)
Running just the front Alcon kit and retaining the stock CSL rear setup gives a front to rear brake bias ratio of 1.82 (so in between the stock M3 and CSL setup - which I've found to be much much better).

As for those going with the AP racing kit - those kit are actually WAY MORE rear biased compared to all the other kits out there. For e.g. the 5570 kit has a front to rear brake bias ratio of 1.61 (very rearward biased).

[glendog74]

Originally Posted by NZ_M3

If you want me to get really technical I can ...

Never!

Mr Gorilla will be along too if you start that

[shimmy]

Originally Posted by NZ_M3

As for those going with the AP racing kit - those kit are actually WAY MORE rear biased compared to all the other kits out there. For e.g. the 5570 kit has a front to rear brake bias ratio of 1.61 (very rearward biased).

All well and good Mr Tom but how does/should that relate to driving styles and performance. Why is one better than the other or are we just assuming BMW have it right and we should try to keep it biased as it was out of the box?

And if you have AP how will playing with pad compound front and back affect this rear bias (if at all)

[DazBlackCSL]

[_Nathan_]

Can you show your calculations please.

[funtime]

Interesting thread, think I'll wait for a conclusion before I waste any money like 'toofastforyou' did, seems he was toofastforhimself

[_Nathan_]

Also - the suspension you have and it's effect on weight transfer under braking may change the optimum bias for your car...

Then you get in to other complexities like tyres and the weather, eg you move the bias rearwards when it is wet.

Basically on a car without bias adjustment is all you are looking for a compromise that suits you and your car's setup and driving style and maybe what is good for one isn't for another...