[toby_2028]

Hi

If I choose to mount a set of 335i breakes on my 2011 184hk 320d, do I need to code performance breaks? And does anybody know how.

320d The rotors is 312 in the front and 300 in the back.
335i The rotors is 348 in the front and 336 in the back

I have everything els covert, just need to know if this setup needs coding and what has to be coded.

I can code using NCS Expert.

Thnaks

[perth1]

Hi,
I'm not a brake system engineer, just a DIY'er, so this advice may not be what you are after. When you change brake disc sizes and caliper piston area, you should in theory change to a matching DSC calibration, and I guess that's what your after with this post. The DSC will apply certain amount of braking on selected wheels to counter-act certain measured G-load and steering angle. Therefore your current 320d DSC calibration will apply a little more brakes during a DSC event with the larger rotors. However when you change certain things on a 320, it is still not the same vehicle as the 335i. For example the weight distribution is not the same, the wheels are not the same, the shocks and roll bars are not the same. Therefore you can't assume that the DSC calibration for 335i is more correct or better than the 320 calibration you have. When you increase brake size both front and rear you should still maintain roughly the correct balance between front and rear brakes. Another problem is that the DSC calibration typically contains some version checks built in, where it typically will only work with certain DME / DDEs. Therefore it may not be possible to load a different ZB# for the DSC from a 335 and make it work in your vehicle.

I suggest after fitting your bigger brakes that you familiarize yourself with how the DSC now operates. Perhaps it is still safe and not over reacting. You should find a large parking lot or closed area on a wet day where it is safe to test your vehicle, and do some high speed tight corner manoeuvres to test your DSC.

Cheers,

[LMB335IS]

Add SPBR to your VO and default code the DSC and NFRM/FRM modules.

[toby_2028]

Originally Posted by perth1

Hi,
I'm not a brake system engineer, just a DIY'er, so this advice may not be what you are after. When you change brake disc sizes and caliper piston area, you should in theory change to a matching DSC calibration, and I guess that's what your after with this post. The DSC will apply certain amount of braking on selected wheels to counter-act certain measured G-load and steering angle. Therefore your current 320d DSC calibration will apply a little more brakes during a DSC event with the larger rotors. However when you change certain things on a 320, it is still not the same vehicle as the 335i. For example the weight distribution is not the same, the wheels are not the same, the shocks and roll bars are not the same. Therefore you can't assume that the DSC calibration for 335i is more correct or better than the 320 calibration you have. When you increase brake size both front and rear you should still maintain roughly the correct balance between front and rear brakes. Another problem is that the DSC calibration typically contains some version checks built in, where it typically will only work with certain DME / DDEs. Therefore it may not be possible to load a different ZB# for the DSC from a 335 and make it work in your vehicle.

I suggest after fitting your bigger brakes that you familiarize yourself with how the DSC now operates. Perhaps it is still safe and not over reacting. You should find a large parking lot or closed area on a wet day where it is safe to test your vehicle, and do some high speed tight corner manoeuvres to test your DSC.

Cheers,

Thank you so much for taking your time explaining your theory.

I can't believe that I did not thought of this. I am an certified mechanic and now I am IT, with cars as my hobby.

I think your theory makes much sense and I completely agree.
The only thing I considered was the front and rear balance, witch should in theory be OK.

The most important thing is the safety systems, and of course this will be effected, and maybe even unbalanced after the swap. - I did not think of this :-)

I definitely take your advice and try out the DSC behavior after the swap to make sure that the system behaves like normal. - If not, I WILL sell the 335i brake kit again, and go back to stock.
I have two children that ride with me every day, and the looks of the car is not worth the risk, if the DSC is not working properly.

Thank again.

[toby_2028]

Originally Posted by LMB335IS

Add SPBR to your VO and default code the DSC and NFRM/FRM modules.

Thank you for the simple and perfect answer.

Do you know that the coding does? Does it decrease the brake pressure or does the coding rebalance the DCS system?