OE brake Upgrade Options

[anothersilver]

I wanted to see what OE brake upgrade maintains the closets brake bias and caliper area to stock. From I can gather it would be the F10 M5 or M2C brake calipers for the front with adapters and rotors (ECS kit for example)? Are they the same caliper and is the carbon or iron caliper better to get? Also, Is there a corresponding rear upgrade?

I'd potentially like to take the car to casusal track days in the future and my friend had a e92 that would fade the brakes quite bad. He ultimately went with a Brembo kit front and rear but these OE options were not available back then. I'm wondering if I might be able to improve the performance without spending on a full BBK.

[MineralWhiteF80]

The factory E92 M3 brakes are actually quite adequate for most people with the correct track brake pad. Depending on your prior track/HPDE experience level and general pace, it's probably best to start by keeping your OEM brake setup, putting on a proper set of track pads and seeing how it does, especially since you say, "casual track days." Then, you can decide if you actually need a brake system that sheds heat better.

The biggest issue with the OEM brake system is the rotor design. It isn't great at cooling. Installing a set of front GiroDisc rotors, brass caliper bushings, with good track pads is actually a great little setup.

I know you said your friend fades his brakes badly, but you need to know exactly what his brake pad brand/model was, what fluid he was running, what his experience level is, and if the track you plan on driving on is notoriously hard on brakes. Usually, people who are fading their brakes are either driving with traction control/MDM turned ON or using an 'in between' brake pad that is considered more of a high-performance street application (like the Ferodo DS2500 or something).

There are a TON of threads on this forum talking about retrofitting other BMW calipers/rotors or other Brembo calipers from other vehicles. There aren't a lot of great options in my opinion and all of them either have issues, or dont provide a significant advantage over the stock setup.

Good thread to read on people's experiences with stock brake system. You should be able to see where you might stack up.
https://www.m3post.com/forums/showthread.php?t=2054245

There are also a lot of people running just a front BBK, and there is sufficient evidence that shows the factory rear brake setup will perform well when paired with only a front BBK.

[M3SQRD]

Originally Posted by MineralWhiteF80

The factory E92 M3 brakes are actually quite adequate for most people with the correct track brake pad. Depending on your prior track/HPDE experience level and general pace, it's probably best to start by keeping your OEM brake setup, putting on a proper set of track pads and seeing how it does, especially since you say, "casual track days." Then, you can decide if you actually need a brake system that sheds heat better.

The biggest issue with the OEM brake system is the rotor design. It isn't great at cooling. Installing a set of front GiroDisc rotors, brass caliper bushings, with good track pads is actually a great little setup.

I know you said your friend fades his brakes badly, but you need to know exactly what his brake pad brand/model was, what fluid he was running, what his experience level is, and if the track you plan on driving on is notoriously hard on brakes. Usually, people who are fading their brakes are either driving with traction control/MDM turned ON or using an 'in between' brake pad that is considered more of a high-performance street application (like the Ferodo DS2500 or something).

There are a TON of threads on this forum talking about retrofitting other BMW calipers/rotors or other Brembo calipers from other vehicles. There aren't a lot of great options in my opinion and all of them either have issues, or dont provide a significant advantage over the stock setup.

Good thread to read on people's experiences with stock brake system. You should be able to see where you might stack up.
https://www.m3post.com/forums/showthread.php?t=2054245

There are also a lot of people running just a front BBK, and there is sufficient evidence that shows the factory rear brake setup will perform well when paired with only a front BBK.

Good summary. You left off one critical component when it comes to brake rotor, pad and caliper temperatures and that’s whether the person is starting to brake too soon and staying on the brakes longer before releasing. This drives temperatures higher than braking at the latest possible point and threshold braking with the least amount of time on the brakes. This actually reduces brake temperatures compared to braking really early and braking with 70-80% of full capability.

The other problem with the stock rotors is their lack of thermal mass and mostly blocked rotor cooling vanes by the aluminum hat design and cast-in steel pins between the aluminum hat and iron rotors. Lack of thermal mass means they can only handle absorbing so much energy in the form of heat and the blocked cooling vanes means the air pumping loss thru the cooling vanes means more heat/temperature remains in the rotors. This is why the retrofit kits with six-p and four-p fixed calipers doesn’t improve brake performance because the weak link are the oem rotors, not the oem one-p sliding calipers.

[M3SQRD]

Originally Posted by anothersilver

I wanted to see what OE brake upgrade maintains the closets brake bias and caliper area to stock. From I can gather it would be the F10 M5 or M2C brake calipers for the front with adapters and rotors (ECS kit for example)? Are they the same caliper and is the carbon or iron caliper better to get? Also, Is there a corresponding rear upgrade?

I'd potentially like to take the car to casusal track days in the future and my friend had a e92 that would fade the brakes quite bad. He ultimately went with a Brembo kit front and rear but these OE options were not available back then. I'm wondering if I might be able to improve the performance without spending on a full BBK.

You’ll need to run the numbers to determine if the F and R caliper torques (not just piston area) are close to the stock brake bias. I’ll run the numbers tomorrow. You’re talking about the f8x CCB caliper and f87C 2NH calipers paired with F/R 400/380 mm rotors? You’ll at least need the F f8x wheel hub+upright and R f8x carrier. The f8x blue caliper still needs the F hub+upright to bolt-on the 4-p fixed front caliper with oem f8x 380 mm F rotor.and essentially a direct bolt-on on the 2-p fixed rear caliper with oem f8x 370 mm R rotor.

[M3SQRD]

E9x M3 stock brakes with F/R 370/360 mm rotors and F/R 60/46 mm single-piston sliding brake caliper has a Front brake bias of 63.3%.

E9x M3 2NH brakes with F/R 400/380 mm rotors and F/R (36, 34, 30)/(28, 28) mm piston dias with F 6-p and R 2-p fixed calipers has a Front brake bias of 67.6%

A 4.3% forward shift in brake bias is significant.

The F caliper area ratio (A2nh/Astock) = 0.93
The R caliper area ratio (A2nh/Astock) = 0.74

This means the e9x M3 brake pedal with 2NH calipers and rotors is going to be very FIRM compared to stock pedal. It’ll be harder to modulate the brake pedal.

Edit - f8x blue calipers with F/R 380/370 mm rotors and F/R (40, 40)/44 mm piston dias with F 4-p and R 2-p fixed calipers has a Front bias of 62.8%

A 0.5% rearward shift in brake bias which is negligible.

The F caliper area ratio (Ablue/Astock) = 0.89
The R caliper area ratio (Ablue/Astock) = 0.93

This means the e9x M3 brake pedal with f8x blue iron calipers and rotors is going to be very FIRM compared to stock pedal. It’ll be harder to modulate the brake pedal.

[gnx]

Originally Posted by M3SQRD

E9x M3 stock brakes with F/R 370/360 mm rotors and F/R 60/46 mm single-piston sliding brake caliper has a Front brake bias of 63.3%.

E9x M3 2NH brakes with F/R 400/380 mm rotors and F/R (36, 34, 30)/(28, 28) mm piston dias with F 6-p and R 2-p fixed calipers has a Front brake bias of 67.6%

A 4.3% forward shift in brake bias is significant.

The F caliper area ratio (A2nh/Astock) = 0.93
The R caliper area ratio (A2nh/Astock) = 0.74

This means the e9x M3 brake pedal with 2NH calipers and rotors is going to be very FIRM compared to stock pedal. It’ll be harder to modulate the brake pedal.

Edit - f8x blue calipers with F/R 380/370 mm rotors and F/R (40, 40)/44 mm piston dias with F 4-p and R 2-p fixed calipers has a Front bias of 62.8%

A 0.5% rearward shift in brake bias which is negligible.

The F caliper area ratio (Ablue/Astock) = 0.89
The R caliper area ratio (Ablue/Astock) = 0.93

This means the e9x M3 brake pedal with f8x blue iron calipers and rotors is going to be very FIRM compared to stock pedal. It’ll be harder to modulate the brake pedal.

I can confirm that the pedal feel with the 2NH is much firmer than stock but I have no issues with modulation. The 2NH on the M2C with the OEM s4007 track pads are considerably harder to modulate even though once up to temperature pedal travel is longer than the e93/2NH application.

[M3SQRD]

Originally Posted by gnx

I can confirm that the pedal feel with the 2NH is much firmer than stock but I have no issues with modulation. The 2NH on the M2C with the OEM s4007 track pads are considerably harder to modulate even though once up to temperature pedal travel is longer than the e93/2NH application.

That’s good to hear that modulation is still there. Sometimes when the pedal gets firm, definitely when it almost feel rigid with zero pedal travel, it becomes very hard, if not impossible, to modulate because the brakes are like an on-or-off switch. The AP Racing brake kit on my ‘03 e46 M3 was bad. Brake release and modulation was terrible but by the 2005 track season I was used to it and I could actually brake consistently lap after lap; however, the first season was so bad that I almost pulled the kit off of the car but brake rotor and pad wear were awesome so I’m glad I didn’t. Switching from the e46 M3 to my ap1 s2000 was a difficult transition!

[anothersilver]

This is great information! Is it possible to see for the ECS M5 front caliper kit if it is the same thing? It might be best to stick with stock as suggested after reading this!

[anothersilver]

Originally Posted by M3SQRD

E9x M3 stock brakes with F/R 370/360 mm rotors and F/R 60/46 mm single-piston sliding brake caliper has a Front brake bias of 63.3%.

E9x M3 2NH brakes with F/R 400/380 mm rotors and F/R (36, 34, 30)/(28, 28) mm piston dias with F 6-p and R 2-p fixed calipers has a Front brake bias of 67.6%

A 4.3% forward shift in brake bias is significant.

The F caliper area ratio (A2nh/Astock) = 0.93
The R caliper area ratio (A2nh/Astock) = 0.74

This means the e9x M3 brake pedal with 2NH calipers and rotors is going to be very FIRM compared to stock pedal. It’ll be harder to modulate the brake pedal.

Edit - f8x blue calipers with F/R 380/370 mm rotors and F/R (40, 40)/44 mm piston dias with F 4-p and R 2-p fixed calipers has a Front bias of 62.8%

A 0.5% rearward shift in brake bias which is negligible.

The F caliper area ratio (Ablue/Astock) = 0.89
The R caliper area ratio (Ablue/Astock) = 0.93

This means the e9x M3 brake pedal with f8x blue iron calipers and rotors is going to be very FIRM compared to stock pedal. It’ll be harder to modulate the brake pedal.

Is it possible to find out what the F10 M5 calipers do to pedal feel and brake bias? ECS Tuning website says they shift the bias just a few percent but I'm curious if they affect the pedal feel as well.

[M3SQRD]

Originally Posted by anothersilver

Is it possible to find out what the F10 M5 calipers do to pedal feel and brake bias? ECS Tuning website says they shift the bias just a few percent but I'm curious if they affect the pedal feel as well.

Are the piston sizes the same size of the f8x CCB and M2C 2NH calipers (rear piston dias are different)? What are the F and R rotor disc ODs and IDs (or the rotor ODs and the Pad Radial Depths)?

And the F10 M5 brakes are being compared to what brake setup?

[M3SQRD]

Originally Posted by anothersilver

Is it possible to find out what the F10 M5 calipers do to pedal feel and brake bias? ECS Tuning website says they shift the bias just a few percent but I'm curious if they affect the pedal feel as well.

I looked at the brake upgrades offered by ECS. It appears they only offer the f10 M5 as a front kit only. Also, it’s not true floating 382 mm rotor but you’re stuck buying replacement rotors only from ECS. If they decide to stop selling them then you’re left with Coleman Racing and Paragon, both of which, make custom rotors. I know Coleman’s pricing is very good but not sure about Paragon’s pricing.

The f8x CCB front caliper has 8.52 in^2 total piston area vs. e9x M3 front has 8.76 in^2 total piston area so the f10 M5 caliper has 0.97 of the e92 M3 front calipers piston area.

The f10 M5 is being paired with a 382 mm rotor vs. the stock e92 370 mm rotor. Ignoring radial pad depths (PRDs) that alter a brake rotors mechanical advantage, the ratio of 382 mm to 370 mm is 1.032.

So multiplying piston area ratio by rotor ratio you get 0.97x1.032 = 1.001 which suggests no shift in forward brake bias IF the PRDs result in the same ratio as the rotor ODs. With only a 3% difference in total piston area won’t be noticeable in the brake pedal feel and stroke. Technically, the f10 M5 caliper will result in a very slightly firmer pedal and a very small reduced pedal travel but they’re practically speaking negligible.

[anothersilver]

Originally Posted by M3SQRD

I looked at the brake upgrades offered by ECS. It appears they only offer the f10 M5 as a front kit only. Also, it’s not true floating 382 mm rotor but you’re stuck buying replacement rotors only from ECS. If they decide to stop selling them then you’re left with Coleman Racing and Paragon, both of which, make custom rotors. I know Coleman’s pricing is very good but not sure about Paragon’s pricing.

The f8x CCB front caliper has 8.52 in^2 total piston area vs. e9x M4 front has 8.76 in^2 total piston area so the f10 M5 caliper has 0.97 of the e92 M3 front calipers piston area.

The f10 M5 is being paired with a 382 mm rotor vs. the stock e92 370 mm rotor. Ignoring radial pad depths (PRDs) that alter a brake rotors mechanical advantage, the ratio of 382 mm to 370 mm is 1.032.

So multiplying piston area ratio by rotor ratio you get 0.97x1.032 = 1.001 which suggests no shift in forward brake bias IF the PRDs result in the same ratio as the rotor ODs. With only a 3% difference in total piston area won’t be noticeable in the brake pedal feel and stroke. Technically, the f10 M5 caliper will result in a very slightly firmer pedal and a very small reduced pedal travel but they’re practically speaking negligible.

Awesome thank you for checking into this! I'm looking at trying to find a second hand BBK but if that does not work out I'll go this route for the front.