[Sukh Singh]

Hi,

I know there is a few threads already covering fitment but would like to confirm a few bits:

1. I have m4 calipers and as I understand from other threads these are a direct fit if I use 370mm discs and not the 380mm used on m cars?

2. do I need to change the master cylinder going from bog standard brakes to the 370mm ones?

3. do the rear calipers need a smaller disc or is the 345mm ok?

Thanks in advance, Sukh

[Tengocity]

The M4 calipers are exactly the same as for the F30. No need for a different master cylinder.

[smrtypants44]

There is coding for the bigger brakes though.

[Watsey]

Originally Posted by smrtypants44

There is coding for the bigger brakes though.

But does the coding provide any significant/noticeable/useful benefits ? I've yet to hear anything conclusive from those that have coded for 'big brakes'.

Interested to hear your before/after experiences if you've been down this route.

[johnung]

Originally Posted by Sukh Singh

Hi,

I know there is a few threads already covering fitment but would like to confirm a few bits:

1. I have m4 calipers and as I understand from other threads these are a direct fit if I use 370mm discs and not the 380mm used on m cars?

2. do I need to change the master cylinder going from bog standard brakes to the 370mm ones?

3. do the rear calipers need a smaller disc or is the 345mm ok?

Thanks in advance, Sukh

You can doublecheck by looking at the back of the Brembo caliper casting. On the front calipers in raised lettering it will say either "340" or "370/380".

You are correct that the 370/380 use a 370mm x 30mm rotor on an F3x, and a 380mm x 30mm rotor on the M3/M4. It's just because the caliper mounting points on the wheel hub differ by 5mm.

The Brembo rear calipers use the 345mm x 24mm rotors.

[johnung]

Originally Posted by Watsey

But does the coding provide any significant/noticeable/useful benefits ? I've yet to hear anything conclusive from those that have coded for 'big brakes'.

Interested to hear your before/after experiences if you've been down this route.

Coding is for the front/rear brake bias, and various front/rear caliper combinations are grouped together. So whether or not brake bias coding is necessary is dependent on which brakes the car had stock and what the new calipers would be.

So if a car is being upgraded to Front 370mm/Rear 345mm from F340/R345 or F340/R330, then no coding should be necessary because the stock brake bias coding is identical.

But if a car is being upgraded to Front 370mm/Rear 345mm from F330/R300 or F312/R300, then brake bias coding is absolutely necessary because the stock brake bias coding is different for the stock single piston brake calipers.

Note: Anyone who purchases the BMW M Performance Brake Kit will see in the installation instructions that it says that the new brakes must be coded. This confuses many people. Rather than write out the explanation that I did above, BMW just made a blanket statement that they all need to be coded. MP brakes are no different than F370/R345 (except for color since they are either red, yellow or orange). So if the car started with F340/R345 or F340/R330, then coding for an MP Brake upgrade is not necessary.

Hope this helps!

[Sukh Singh]

Cheers for the reply Chaps!

I'm going from single piston cliper to m4 calipers, so will need coding.

Is ther any additional hardware I need to make them fit physically?

[blau3er]

Originally Posted by Tengocity

The M4 calipers are exactly the same as for the F30. No need for a different master cylinder.

Some F3x models do get a puny master cylinder - maybe that’s what the OP is referring to?

Your right through, since BMW sell the M Perf retrofit without including a master upgrade they will be fine!

[Sasquartch]

If only the front brakes are upgraded then the front / rear bias will be wrong

Whilst coding might be able to change the bias it might not be optimal if you're not using a valid combination of front / rear brake components. So I guess it's theoretically possible you could make your braking worse by doing this change.

Whether there would be any real world difference I don't know. But I do know that BMW will have spent a lot of development time on something so critical to safety so personally I'd keep a matching set of front / back components

[Sukh Singh]

cheers for the replies

will be a full set of M4 calipers if I do go for it

[blau3er]

Originally Posted by Sukh Singh

cheers for the replies

will be a full set of M4 calipers if I do go for it

Which are identical in every way to the M Sport calipers taken off any high powered 3 / 4 series (28i upward and 25d upward)

[SantaEugence]

Originally Posted by blau3er

Which are identical in every way to the M Sport calipers taken off any high powered 3 / 4 series (28i upward and 25d upward)

This. Don't be fooled into paying extra just because someone tells you they're M4 calipers

[Sukh Singh]

Originally Posted by SantaEugence

This. Don't be fooled into paying extra just because someone tells you they're M4 calipers

cheers bud

I already have the calipers, they were ment to go on my m3 in place of ceramic brakes but didn't.

[SantaEugence]

Originally Posted by Sukh Singh

cheers bud

I already have the calipers, they were ment to go on my m3 in place of ceramic brakes but didn't.

What happened to the ceramic brakes? Happy to swap