[MacklinUSOB]

Hey everyone.

So it is time for some new rotors and have been toying with this idea for a while and wanted to put a feeler out to see if anyone has tried to retrofit the P337A option on a 328i with standard brakes. On the 328i getting the M-Sport Package included a modest brake upgrade from the standard 312mm rotors to 330mm rotors along with a pad material upgrade (P337A) while still maintaining the single piston caliper. I suspected that the caliper and carrier were the same for all single piston fronts so I went digging on Real OEM. Attached is a comparison chart showing the different part numbers for P337A=Yes and P337A=No. You will see that the only different part (aside from the rotors and pads obviously) is the protection plate. In theory this means that anyone on standard brakes can retrofit P337A simply by changing the protection plate and rotors. I was planning on getting new plates anyway since mine are not looking great. The rotors and plates are practically no more expensive than the standard ones so this seems to me like a no brainer. Feel free to respond with your thoughts!

[MacklinUSOB]

I went over this with a friend who has access to dealer parts network (in addition to checking RealOEM and BimmerCat) and confirmed that this should work. Only one asterisk, it can only be done on a car with a build date of 07/2013 or LATER.

[Z K]

Is the protection plate replacement needed? That just protects the suspension components from brake dust and heat. You'd think it'd be fine with such a small change?

Also, since the rotor is bigger, would the stock caliper fit over the larger rotor without changing the caliper carrier?

[MacklinUSOB]

Originally Posted by Z K

Is the protection plate replacement needed? That just protects the suspension components from brake dust and heat. You'd think it'd be fine with such a small change?

Also, since the rotor is bigger, would the stock caliper fit over the larger rotor without changing the caliper carrier?

Edit: See bottom comment

[Z K]

Originally Posted by MacklinUSOB

I'm not entirely sure if it's strictly needed or not but I was planning on replacing mine either way. Will compare the two when I have them off.

In this case a larger carrier isn't needed. The carrier part numbers between the stock and m-sport package cars are identical, as are the hubs/mounting points.

Please let us know when you get it. This may be a good easy upgrade for those with standard brakes.

All we'd need is a larger rotor and some pads to get equivalent P337A brakes. Adding brake shields are not a big deal but we'll see if it's strictly needed.

[MacklinUSOB]

So I went to go fit all the new parts on Friday but it looks like I found a glitch in the BMW part catalog. There are no retroactive part numbers for the carrier but it still was several mm short despite multiple sources saying there is no difference. I went back over the BMW part catalog and there is no indication of a change either.

If you have a 7/2013 build or later this should work for you. This was the first production month of M-Sport cars and all 28s (must have) got a revised carrier from then forward.

[Z K]

Originally Posted by MacklinUSOB

So I went to go fit all the new parts on Friday but it looks like I found a glitch in the BMW part catalog. There are no retroactive part numbers for the carrier but it still was several mm short despite multiple sources saying there is no difference. I went back over the BMW part catalog and there is no indication of a change either.

If you have a 7/2013 build or later this should work for you. This was the first production month of M-Sport cars and all 28s (must have) got a revised carrier from then forward.

No different part number but a different caliper carrier? Are you going to get new carriers and see if the newer ones will work with this set up?

[MacklinUSOB]

Originally Posted by Z K

No different part number but a different caliper carrier? Are you going to get new carriers and see if the newer ones will work with this set up?

I'm certain the new carriers would work on this setup but it really kills the value proposition of this upgrade. At this point it makes more financial sense to hop to the 335i calipers, if they will even work with my existing carriers. I'd totally suggest someone with a 7/2013 build date or later to carry this torch across the line.

[Mollyran]

Just a note, the carrier is actually different here is the realoem:
https://www.realoem.com/bmw/enUS/sho...diagId=34_1968