[blau3er]

Originally Posted by xpro

Coding will not have a major effect on braking performance. I would say theres airlock in the system. Granted, fitting more pots will strain the master cylinder for sure but not so much that they wont brake. A couple of members had already successfully fitted M5 and Porsche callipers without doing the master cylinder

For proper bleeding you need a pressurised tool that forces all the fluid out while leaving all nipples open so that all the air is forced out.
When the airlock is bad, regular vacuum tool or foot pumping will not get rid of the airlock.

Which forum members have fitted the F10 M5 fronts without the larger MC?

[Logicoeur]

Originally Posted by blau3er

Which forum members have fitted the F10 M5 fronts without the larger MC?

Only people who didn't have 4piston Brembos originally. So that's OP in his 328. Anyone with a 335/340i already have the correct sized MC. It's the same used in the Ms, which makes sense since the calipers are exactly the same.

[xpro]

Originally Posted by blau3er

Which forum members have fitted the F10 M5 fronts without the larger MC?

I'll see if I can find it. I saw it only a few days ago. Blue F30 with Porsche yellow BBK. Plug and play fit with brackets.

Could have been on the UK forums, I'll take a look

[blau3er]

Originally Posted by xpro

I'll see if I can find it. I saw it only a few days ago. Blue F30 with Porsche yellow BBK. Plug and play fit with brackets.

Could have been on the UK forums, I'll take a look

Ahh OK, so not F10 M5 calipers

[blau3er]

Originally Posted by Logicoeur

Only people who didn't have 4piston Brembos originally. So that's OP in his 328. Anyone with a 335/340i already have the correct sized MC. It's the same used in the Ms, which makes sense since the calipers are exactly the same.

Yeh aware of this case with the OP & yes the MC’s on cars with the blue brakes from factory are the correct size for this upgrade.

[Logicoeur]

Originally Posted by blau3er

Yeh aware of this case with the OP & yes the MC’s on cars with the blue brakes from factory are the correct size for this upgrade.

Not only blue brakes. Standard front brakes on the 335i/340 are Grey 4piston Brembos. Same as the blue/red/orange/yellow regardless of the rotor size. The fixed ears on the caliper ears are changed and that's it. MC is the same.

[blau3er]

Originally Posted by Logicoeur

Not only blue brakes. Standard front brakes on the 335i/340 are Grey 4piston Brembos. Same as the blue/red/orange/yellow regardless of the rotor size. The fixed ears on the caliper ears are changed and that's it. MC is the same.

Correct, the cars with the grey 340mm 4 pots also get the larger MC

[Kel918]

Originally Posted by xpro

Coding will not have a major effect on braking performance. I would say theres airlock in the system. Granted, fitting more pots will strain the master cylinder for sure but not so much that they wont brake. A couple of members had already successfully fitted M5 and Porsche callipers without doing the master cylinder

For proper bleeding you need a pressurised tool that forces all the fluid out while leaving all nipples open so that all the air is forced out.
When the airlock is bad, regular vacuum tool or foot pumping will not get rid of the airlock.

Thanks for the advice will look into a motive bleeder

[Kel918]

just got the car back, it was the master cylinder that needed to be changed.

[Kel918]

I definitely need to get the brakes coded in. I haven't really driven the car in a couple of weeks but I just expected the brakes to be more responsive. Though I've been driving my panamera turbo all this time so I guess I expected the new calipers to be the same or better than the porsche.

[blau3er]

I’m willing to bet that there is still air in the system, and it needs a proper bleed using ISTA.

I’m fairly confident that this will get things working as they should.

I can confirm that these brakes bite hard and do not have a soft pedal

[Kel918]

Originally Posted by blau3er

I’m willing to bet that there is still air in the system, and it needs a proper bleed using ISTA.

I’m fairly confident that this will get things working as they should.

I can confirm that these brakes bite hard and do not have a soft pedal

I think so too, that's why I have to get them coded, again my opinion is biased because I'm comparing to a different car.

[draggy]

Originally Posted by blau3er

Ahh OK, so not F10 M5 calipers

Here you go

[blau3er]

Originally Posted by draggy

Here you go

That’s my car

[draggy]

Originally Posted by blau3er

That’s my car

glad you're still around

[5mall5nail5]

Originally Posted by Kel918

It makes perfect sense since you already had the 4 piston grey brembo's and only went up to 6 pistons on the m5

This isn't really how it works, though.

The number of pistons is irrelevant. Hydraulic systems are all about displacement and displacement, just like engines, is all about volume (cubic inch, cubic mm, whatever). So if the stock front pistons, say, had single 1.90" pistons then the surface area behind the piston is 16.62 sq in. Converting to a 4-piston caliper with 1.65" pistons results in 34.2 sq in. You can see how a simple 1:1 swap of these pistons is going to result in much less travel of the brake pistons vs. the pedal without an MC change or other clever pump trickery.

I don't have that specs of the F10 M5 calipers but "you only added 2 more pistons" could be insignificant or quite significant. When I built my custom Wilwood kit for my other BMW I went with 6-piston SL6R calipers but with staggered piston sizes that, when added up, were within the same region of surface area as the stock single piston calipers so I did not have to swap MCs, etc.

The F30 is trickier yet - the coding might adjust brake bias, but more over, it actually adjusts some sort of valving within the ABS unit. I put the oranage M Performance BBK on my car and drove around the neighborhood with them fully bled and it was garbage - the pedal went nearly to the floor, it'd "lose pressure" if you stayed on it, it was just wrong. Fired up the laptop, loaded E-Sys and programmed it for the sport brakes - all better, 100%.

So be careful - if you have the piston measurements we can do the math (its very simple) but swapping these calipers (with two piston rears, too) may put the system outside of what it can displace w/o a MC change... coding or otherwise.

[blau3er]

Originally Posted by 5mall5nail5

This isn't really how it works, though.

The number of pistons is irrelevant. Hydraulic systems are all about displacement and displacement, just like engines, is all about volume (cubic inch, cubic mm, whatever). So if the stock front pistons, say, had single 1.90" pistons then the surface area behind the piston is 16.62 sq in. Converting to a 4-piston caliper with 1.65" pistons results in 34.2 sq in. You can see how a simple 1:1 swap of these pistons is going to result in much less travel of the brake pistons vs. the pedal without an MC change or other clever pump trickery.

I don't have that specs of the F10 M5 calipers but "you only added 2 more pistons" could be insignificant or quite significant. When I built my custom Wilwood kit for my other BMW I went with 6-piston SL6R calipers but with staggered piston sizes that, when added up, were within the same region of surface area as the stock single piston calipers so I did not have to swap MCs, etc.

The F30 is trickier yet - the coding might adjust brake bias, but more over, it actually adjusts some sort of valving within the ABS unit. I put the oranage M Performance BBK on my car and drove around the neighborhood with them fully bled and it was garbage - the pedal went nearly to the floor, it'd "lose pressure" if you stayed on it, it was just wrong. Fired up the laptop, loaded E-Sys and programmed it for the sport brakes - all better, 100%.

So be careful - if you have the piston measurements we can do the math (its very simple) but swapping these calipers (with two piston rears, too) may put the system outside of what it can displace w/o a MC change... coding or otherwise.

I have posted the piston sizes and info in this thread

[Kel918]

Originally Posted by 5mall5nail5

This isn't really how it works, though.

The number of pistons is irrelevant. Hydraulic systems are all about displacement and displacement, just like engines, is all about volume (cubic inch, cubic mm, whatever). So if the stock front pistons, say, had single 1.90" pistons then the surface area behind the piston is 16.62 sq in. Converting to a 4-piston caliper with 1.65" pistons results in 34.2 sq in. You can see how a simple 1:1 swap of these pistons is going to result in much less travel of the brake pistons vs. the pedal without an MC change or other clever pump trickery.

I don't have that specs of the F10 M5 calipers but "you only added 2 more pistons" could be insignificant or quite significant. When I built my custom Wilwood kit for my other BMW I went with 6-piston SL6R calipers but with staggered piston sizes that, when added up, were within the same region of surface area as the stock single piston calipers so I did not have to swap MCs, etc.

The F30 is trickier yet - the coding might adjust brake bias, but more over, it actually adjusts some sort of valving within the ABS unit. I put the oranage M Performance BBK on my car and drove around the neighborhood with them fully bled and it was garbage - the pedal went nearly to the floor, it'd "lose pressure" if you stayed on it, it was just wrong. Fired up the laptop, loaded E-Sys and programmed it for the sport brakes - all better, 100%.

So be careful - if you have the piston measurements we can do the math (its very simple) but swapping these calipers (with two piston rears, too) may put the system outside of what it can displace w/o a MC change... coding or otherwise.

I changed the MC and it's working great, I just want to code the updated brakes to see the difference.

[5mall5nail5]

Originally Posted by blau3er

I have posted the piston sizes and info in this thread

Nice - I didn't read for technical specs just wanted to chime in and let that poster know that the number of pistons is only part of the equation.

Originally Posted by Kel918

I changed the MC and it's working great, I just want to code the updated brakes to see the difference.

Nice - depending on the MC size and ratios you may not need/want to code. If it is working great now, I don't think the coding will make it "more great" - my brakes felt like absolute garbage after the M Perf install, and coding put it right back to stock feeling or dare I say even a little too grabby at low speed.

[5mall5nail5]

Originally Posted by Logicoeur

The 335i and m3 MC are the same. That's why we don't have to change our MC when going to 370/345. The calipers are the same whether they came off an M with 380 or not.

Coding is for abs,so you will need to change it to the 370/380 option. I believe it's by brake code though, so S2NHA or whatever the Msport/MPerf blue/red/yellow/orange are. What tool to use to do this I do not recall. ISTA+?

Not accurate -

I have an N26 328 which obviously does not have the 370mm/380mm option. I don't have PNs handy but I also did not have to change my MC to go to 370/345mm. Coding is not only for the ABS but is absolutely for pressure restriction/proportioning. My pedal felt like I forgot to bleed my brakes (used a Motive). I drove around the block with garbage pedal, pulled into garage, coded performance brakes, and its been amazing since. No MC change, no bleeding further, etc.

Edit: MC PN# on my car going by my VIN is 34336851095

If you look that part up, it's the same part on ALL F20/F21/F22/F23/F30/F31/F34/F32/F33/F36 from the "316d" to the 355/340/etc. NO F80 models use the same MC but ALL of the non-M cars use it.

[blau3er]

Originally Posted by 5mall5nail5

Not accurate -

I have an N26 328 which obviously does not have the 370mm/380mm option. I don't have PNs handy but I also did not have to change my MC to go to 370/345mm. Coding is not only for the ABS but is absolutely for pressure restriction/proportioning. My pedal felt like I forgot to bleed my brakes (used a Motive). I drove around the block with garbage pedal, pulled into garage, coded performance brakes, and its been amazing since. No MC change, no bleeding further, etc.

Edit: MC PN# on my car going by my VIN is 34336851095

If you look that part up, it's the same part on ALL F20/F21/F22/F23/F30/F31/F34/F32/F33/F36 from the "316d" to the 355/340/etc. NO F80 models use the same MC but ALL of the non-M cars use it.

It's not 100% clear from this post, but it would appear you are suggesting that no regular F3x car shares the same MC p/no as the F8x ///M cars?

If so, this is inaccurate.

Your car with the base brakes (328) would not have the larger MC, and you are correct that this smaller MC is in fact capable of powering the BMW M Performance upgrade brakes (370 / 345) this is also verified by the fact that BMW themselves sell the orange / red / yellow brake retrofit kit without a MC upgrade included as part of the package.

However, on MOST (but not all) cars that are optioned from the factory with blue the S2NHA M Sport brakes (which have identical piston sizes to the M Perf) the cars come with the same MC as the F8x ///M cars.

In the USA, this is p/no: 34337849878 (for left hand drive cars) and in the UK it is p/no: 34337849879 (for right hand drive cars)

ETK:

https://bimmercat.com/bmw/en/parts/i...9878/appliance

For example, if your N26 328 had been optioned from new with the M Sport brakes, it would have been fitted with 34337849878, as shown on the ETK:

https://bimmercat.com/bmw/en/search/...26/ECE/34_1966

[5mall5nail5]

Originally Posted by blau3er

It's not 100% clear from this post, but it would appear you are suggesting that no regular F3x car shares the same MC p/no as the F8x ///M cars?

If so, this is inaccurate.

Your car with the base brakes (328) would not have the larger MC, and you are correct that this smaller MC is in fact capable of powering the BMW M Performance upgrade brakes (370 / 345) this is also verified by the fact that BMW themselves sell the orange / red / yellow brake retrofit kit without a MC upgrade included as part of the package.

However, on MOST (but not all) cars that are optioned from the factory with blue the S2NHA M Sport brakes (which have identical piston sizes to the M Perf) the cars come with the same MC as the F8x ///M cars.

In the USA, this is p/no: 34337849878 (for left hand drive cars) and in the UK it is p/no: 34337849879 (for right hand drive cars)

ETK:

https://bimmercat.com/bmw/en/parts/i...9878/appliance

For example, if your N26 328 had been optioned from new with the M Sport brakes, it would have been fitted with 34337849878, as shown on the ETK:

https://bimmercat.com/bmw/en/search/...26/ECE/34_1966

Thanks - I should have been more clear - the poster said "The 335i and m3 MC are the same. That's why we don't have to change our MC when going to 370/345."

That part is not true - the 335i and M3 by default are NOT the same. I have had a number of people tell me that their 335s (base) have M3 MC's and "can I swap brakes because of this?" which is obviously loaded several ways.

That said, take a look at the 34337849878 cross reference you linked. You'll find that the 335i is NOT listed as cross reference: https://www.realoem.com/bmw/enUS/par...78&series=F30N

In fact, if you go to the 335i specifically, regardless of VIN or package, you'll see only one master cylinder available for that vehicle, of which is shared with every other non-M car, and no F8x.

I am only trying to squash the "335i's have the same MC as M3s" - no they don't, not according to any ETK, S2NHA or otherwise.