Best retrofit for M3 brakes?

Redd wrote

If you do plan to use China rotors, insist only on Dicase brand. Quality can vary a lot between manufacturers and Dicase is considered to be the top China brand for brakes as they are also an OEM brake component manufacturer.

are these rotors lighter than oem?

atopa2002 wrote

are these rotors lighter than oem?

Never weighed them but the Dicase 380mm weighed similar to my original Brembo 380mm discs just by hand feel.

has anybody tried g80 m3 brakes on e9x? Just seen some come up for sale for same price as f8x brakes

ninja88 wrote

has anybody tried g80 m3 brakes on e9x? Just seen some come up for sale for same price as f8x brakes

I would assume not being that the wheel bolt spacing is different on the g series.

ninja88 wrote

has anybody tried g80 m3 brakes on e9x? Just seen some come up for sale for same price as f8x brakes

They are radial mounted, someone would need to make a custom bracket and find a suitable rotor.

andrihallik wrote

Right now used the old brake lines that were on the e92. Probably upgrading to braided lines when next brake pad change comes - right now used the same pads that came with the used 7 series calipers, half worn pads for testing.

So far ~5000km the wear on the disc is even - on top side of the disc the lip/wear continues from the same spot that the original e92 m3 pads touched so ~1mm from top. On bottom side where the pad was cut they go over the disc little bit so no lip there anymore. With new pads i can use them as template to get correct size pads.

I used G11 7 series 2017 non m brakes. (not painted calipers)
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The M brakes on 7 series are bigger (the two cylinders on front of the caliper have some room). This video is very informative but misses the non painted calipers, exactly the same but not painted.

Bumping this up, did you by chance find a better suited pad without having to trim the 7 series one?

With the release of brakets to use gt350 or gt350 Ford calipers and seeing how inexpensive they are what info on bias for that set up with stock rear or f8x m rear since most run that?

71velle wrote

With the release of brakets to use gt350 or gt350 Ford calipers and seeing how inexpensive they are what info on bias for that set up with stock rear or f8x m rear since most run that?

Do you know the caliper piston sizes, rotor diameter and pad profile/fmsi number?

M3SQRD wrote

Do you know the caliper piston sizes, rotor diameter and pad profile/fmsi number

Not sure of piston size but it will use the f8x 380mm rotor and std Ford pads gr3z-2001-b or ebc dp33042z

71velle wrote

Not sure of piston size but it will use the f8x 380mm rotor and std Ford pads gr3z-2001-b or ebc dp33042z

Is the GT350 caliper the one in the picture below (fixed top bridge)? It is used with the stock 370 mm OD front rotor? Are you certain the EDC dp33042z (FMSI D1784) pad radial depth fits on the e9x M 57 mm rotor annulus radial depth? I haven’t scaled the D1784 pad radial depth (PRD) but what I was able to find online is its PRD might be 64 mm (possibly longer than 64 mm). The 7 mm longer PRD means the pad will overhang the e9x M rotor ID or rotor OD or both the ID & OD depending on where the GT350 caliper radial position is located. The f8x blue 380 mm OD rotor has a 70 mm PRD so this wouldn’t work either because there would be a 6 mm of unswept rotor area.

M3SQRD wrote

Do you know the caliper piston sizes, rotor diameter and pad profile/fmsi number?

Same as C63 AMG (W204) front - 34/36/38mm - 3059mm x 2 per caliper

Stock M3 piston area front 60mm - 2826 x 2.

It will shift brake bias forward, have a longer and softer pedal. Might be fine for street use but not what I'd what for balance on the track at the limit.

tdott wrote

Same as C63 AMG (W204) front - 34/36/38mm - 3059mm x 2 per caliper

Stock M3 piston area front 60mm - 2826 x 2.

It will shift brake bias forward, have a longer and softer pedal. Might be fine for street use but not what I'd what for balance on the track at the limit.

I know the piston areas of the e9x M3. Using piston areas from one side of the caliper, you get

%diff = (3060-2827)/2827 x 100 = 8.24%

An 8.24% difference in piston area isn’t going to result in a much longer and softer pedal. What rotor is this supposed to be paired with - e9x M or f8x? From what I found online, the GT350 PRD is 64 mm which means it won’t fit on the e9x M front rotor (57 mm PRD). So this leaves only the f8x 380 mm OD rotor?

The Essex/AP f87C brake kit wrt the stock 2NH brake setup has a -4.7% decrease in front piston area (shorter travel & stiffer pedal) and a +7.2% increase in rear piston area (longer travel & softer pedal) yet the Essex/AP f87C brake kit pedal feel is just fine. Essex/AP f87C brake kit brake bias is 0.678 vs. the 2NH brake bias of 0.676. Different rotor diameters produce the same relative front to rear brake torques.

M3SQRD wrote

I know the piston areas of the e9x M3. Using piston areas from one side of the caliper, you get

%diff = (3060-2827)/2827 x 100 = 8.24%

An 8.24% difference in piston area isn’t going to result in a much longer and softer pedal. What rotor is this supposed to be paired with - e9x M or f8x? From what I found online, the GT350 PRD is 64 mm which means it won’t fit on the e9x M front rotor (57 mm PRD). So this leaves only the f8x 380 mm OD rotor?

The Essex/AP f87C brake kit wrt the stock 2NH brake setup has a -4.7% decrease in front piston area (shorter travel & stiffer pedal) and a +7.2% increase in rear piston area (longer travel & softer pedal) yet the Essex/AP f87C brake kit pedal feel is just fine. Essex/AP f87C brake kit brake bias is 0.678 vs. the 2NH brake bias of 0.676. Different rotor diameters produce the same relative front to rear brake torques.

Yes for this u would need to use the f8x 380mm rotor.

https://ctsvbrakeswap.com/collections/bmw-kits/products/bmw-e9x-m3-gt350-caliper-bracket

ctsvbrakeswap just released the Mustang GT350 Caliper Bracket for our cars. The calipers are kinda cheap too and pad sweep looks good compared to the other ones

liverpoolreds8 wrote

Bumping this up, did you by chance find a better suited pad without having to trim the 7 series one?

No.. but i bought new brembo pads and cut them. No more overhang.
Takes literally 10 minutes to cut them on bench grinder.

Have done 10k km now and 3 trackdays, everything gucci so far.

Has anyone tried the W205 C63S caliper on the front?
Piston size 32/34/38 makes them almost identical in area to the stock brakes, so should keep brake force more or less equal.

Would they have a similar bracket to the W204 caliper?

Stock MB rotor is 390mm so not sure if the outer pad radius would be an issue.

13LemansBlue92 wrote

Has anyone tried the W205 C63S caliper on the front?
Piston size 32/34/38 makes them almost identical in area to the stock brakes, so should keep brake force more or less equal.

Would they have a similar bracket to the W204 caliper?

Stock MB rotor is 390mm so not sure if the outer pad radius would be an issue.

Yes. It has been considered by some owners. Total piston area is good but pad options are poor for the f8x 380 mm OD rotor.

I work at a ford dealer so got a great price on the gt350 front and rear calipers. Just need to pick up caliper brackets. Hoping someone comes out with the rear caliper brackets as well.

What options are there for the rear?

Williamgoody312 wrote

What options are there for the rear?

Why are you only asking about the rear? You need a front and rear calipers with appropriate piston areas to maintain the forward brake bias as well as brake pedal feel, stroke and firmness.

F8x blue 4-piston 380 mm OD rotor front and 2-piston 370 mm OD rotor rear is commonly used. There are two options - Swapping f8x knuckles or using custom caliper brackets to mount the calipers. The f8x/f87 CCB/2NH 6-piston 400 mm OD rotor front and 4-piston 380 mm OD rotor rear is another viable option and is a virtually simple bolt-on with custom caliper brackets. Other options are out there but I’d recommend using one of the f8x/f87 oem options.

M3SQRD wrote

Why are you only asking about the rear? You need a front and rear calipers with appropriate piston areas to maintain the forward brake bias as well as brake pedal feel, stroke and firmness.

F8x blue 4-piston 380 mm OD rotor front and 2-piston 370 mm OD rotor rear is commonly used. There are two options - Swapping f8x knuckles or using custom caliper brackets to mount the calipers. The f8x/f87 CCB/2NH 6-piston 400 mm OD rotor front and 4-piston 380 mm OD rotor rear is another viable option and is a virtually simple bolt-on with custom caliper brackets. Other options are out there but I’d recommend using one of the f8x/f87 oem options.

If you already have something on the front.

Williamgoody312 wrote

If you already have something on the front.

Ok but what’s on the front affects what can be used on the rear unless you prefer a brake pedal that requires 6” of travel (piston area is way too large) before the brakes are applied or virtually zero” of travel to hit full braking (piston area is way too small). You should not randomly pick front and rear brake calipers unless you want one of the issues described above.

What do you have on the front? Do you know the front piston sizes or total piston area?