[heco94]

Foremost, my apologies to flood the forum with something that may or may not already have been covered, but I've found myself in what I'd describe as a pickle.

I'm to replace my pads and rotors, and I have no idea which ones to order, I know, idiot, but hear me out; I have a 15' m sport, with the grey calipers (non-performance package), I had assumed all m sports had the 370x30 rotors, I thought nothing of it, but I noticed there were pad options galore, S2NHA and P337A. I do a bit of googling and realize, I'm wrong, rotors come in 340 for the m sport as well.

I try to figure out which package I have by code, based off of the info I have from the dealer and the crap I have in the car, but I can't seem to make high or low of it, so I measure my rotors, and they seem to be the 340's (I didn't take my wheel off but I'm pretty sure im correct)

I've done some searching online but again, I still am not sure what package I have regarding brakes so here I am. Heres my question; based off of what I've described, grey calipers, 340 rotors, m sport from 2015, am I a S2NHA pad or a P337a pad? Does my ghetto measurements of 340 rotors in the front seem correct?

Based off of this, I think im a p337 (although they even say here it could be either or): https://www.bimmerworld.com/About-Us...-Sport-Brakes/


Thank you guys for the help!

[328iX]

Gray is 340mm, Blue (or any colored calipers) is 370mm

That article you posted sums it up well

[heco94]

Regarding pads is the greater confusion

[kern417]

Calipers for the 340mm and 370mm brakes use the same brake pads. The OEM codes may be different materials or just separate based on caliper, but the physical size and fitment is the same.

[Logicoeur]

Originally Posted by 328dX

Gray is 340mm, Blue (or any colored calipers) is 370mm

That article you posted sums it up well

Blue comes in 340 or 370. From the factory it depended on the engine in the car. Buying used the PO could have put on either. Check the stamp on the back of the calipers.

Red, yellow, and orange are always 370.

The rears in any color are the same size.

Like kern says, pads for any of the 4piston Brembos (any painted color) will physically fit no problems. Same for the painted rears.

[mbanks21]

Anyone have thoughts on 1 piece vs 2 piece rotors for 100% street use? Is it worth the money for 2 piece?

[Logicoeur]

Originally Posted by mbanks21

Anyone have thoughts on 1 piece vs 2 piece rotors for 100% street use? Is it worth the money for 2 piece?

I wouldn't. You're better off spending that money on some decent forged wheels and tires. Youd still she'd some mass per axle and feel the benefits. I got some 19lb wheels and could feel the difference in inertia when starting from a stop, or accelerating, immediately.

If you already have wheels and tires then yes, the rotors will be good.

[mbanks21]

Originally Posted by Logicoeur

I wouldn't. You're better off spending that money on some decent forged wheels and tires. Youd still she'd some mass per axle and feel the benefits. I got some 19lb wheels and could feel the difference in inertia when starting from a stop, or accelerating, immediately.

If you already have wheels and tires then yes, the rotors will be good.

Already have wheels and tires, focusing on brakes now. Basically would I be able to tell a difference on the street with 2 piece rotors. If yes then I'll spend the money.

[Logicoeur]

Originally Posted by mbanks21

Already have wheels and tires, focusing on brakes now. Basically would I be able to tell a difference on the street with 2 piece rotors. If yes then I'll spend the money.

No you won't really, not as braking power/performance. The two piece type only remove rotational mass which is what getting lighter wheels does. Depending on the weight of your wheels you may be able to feel the decrease in unsprung weight, or you may not. Generally, if you aren't tracking there's no real reason to go two piece, other than racekor points.

[B1ue52]

I have the same issue as the OP. I have used a combination to work out what part codes I have in regards to disks and pads fronts of looking up the part codes on the BMW parts site and the Bimmerpost article cited above. For example they are the M Sport variant (pre blue caliper) P337 option single piston grey calipers and what BMW tell me use part codes of:

Front Disks: 34116792221 (I'm guessing based on the pads as BMW doesn't seem to list disks for my car?!?)
Front Pads: 34106859181

Rear Disks: 34216792227
Rear Pads: 34216873093

I have a couple of questions:

1. When ordering replacement aftermarket pads, how do I discern if my brakes are ATE or Brembo? Pretty much every site lists both options but I have no idea to know which ones I need unless I remove the old pads first and check the shape.

2. As my car has the lower diameter rotors, when considering replacing them, can I use larger diameter rotors without having to swap out calipers etc? Are they just a bolt in replacement?

3. Suggestions for a mid-range rotor replacement such as Brembos etc. Would prefer drilled or grooved and drilled.

Thanks for any help in advance

Andy

[JaredG_F30]

M Sport Brake Upgrade 2 (S2NH/S2NHA) (pads, calipers, rotors): Sometime during 2012-2013 production BMW changed the M Sport Brake option to include larger front and rear rotors, a different front caliper (still 4-piston Brembo), and 2-piston Brembo rear calipers. It was a $650 option but still called "M Sport S2NHA" and could be added to ANY trim package (even a base model). This kit was the same as the M Sport offered in Canada/Europe. The calipers should be blue with an ///M logo but there's a slim chance they could be grey/unfinished with no logo. The front pads were a similar aggressive Euro-spec pad as above. The rotors are blank but the dimpled/slotted rotors from the M Performance brake kits are a direct fit if you want to change their appearance.

Specs:
Front: Brembo 4-piston calipers, grey or blue; 370mm blank brake rotors
Rear: Brembo 2-piston calipers, grey or blue; 345mm blank brake rotors

This article is more inclusive

https://www.turnermotorsport.com/t-b...ke-Differences

Originally Posted by 328dX

Gray is 340mm, Blue (or any colored calipers) is 370mm

That article you posted sums it up well