[JoeyBananaz18]

As the title states, I'm pondering the idea of upgrading my 335 brakes to the standard OEM M3 brakes. I've already learned that a new mounting bracket would need to be fabricated to mount the calipers, And I may need to upgrade to stainless steel brake lines. I also know that my rotors don't exactly have fins, but more of a channel for cooling where as the M3 rotors are cross drilled and have the vented fins. What I'd like to know is some specs between OEM 335 brakes and OEM M3 brakes (diameter size, piston per caliper, contact surface area ect.)
Given those specs, I'd like to know which are important when upgrading brakes.

A BBK would be great but, i dont have the money to shell out. Im hoping i can take some of this info, and see if it's financially viable for me to do this upgrade. Thanks.

[e90pilot]

I think the M3 has a different master cylinder. It also has a different brake booster and DSC unit. I'm not sure if you really need any of those parts. As far as piston count, they're all single piston floating calipers.

What exactly is your goal with the brakes? Do you track your car? Are you getting fade? Are you looking for shorter stoping distances? Better pedal feel?

[cstmx_ryder]

why don't you just upgrade the pads? I think that should be more than sufficient for DD and some track time...........

[Ghost170]

Originally Posted by e90pilot

I think the M3 has a different master cylinder. It also has a different brake booster and DSC unit. I'm not sure if you really need any of those parts. As far as piston count, they're all single piston floating calipers.

What exactly is your goal with the brakes? Do you track your car? Are you getting fade? Are you looking for shorter stoping distances? Better pedal feel?

+1

[TurboBimmer]

It depends what your use for the car is. Tracking? On a racetrack the M3 brakes aren't that much better compared to the 335i brakes.

You may want to try a more performance oriented pad compund first.

Besides, a BBK probably won't cost more than the M3 brakes, unless you can get them from a wrecked car.

[JoeyBananaz18]

I want to be 100% completely up front with everyone who reads this thread- I'm mostly looking into this for aesthetic reasons.

Heres the story. I'm watching where all my modifications are taking my car and from a "looks" perspective,i could not be happier. My 2 biggest mods have been my H&R coils and my SF-71s that just recently got mounted. I absolutely love the way my car looks.

I was looking at my brakes the other day through my new 19s, and felt that something gets lost when your eye gets to the rotors and calipers. I thought about painting my calipers but i feel like they would be too small and it would look tacky. I thought that by upgrading to M3 brakes, it would add a bit of a sporty flair that better suits the car.

The cross drilled rotors would look amazing, but I'm more interested in if there is a difference in size between the 335 and M3 brakes. And if there is, will there be a more noticeable feel in performance, such as stopping distance and pedal feel.

regarding price, I've seen OEM sets that have been replaced with BBKs go for about $300 or so.

Just wondering if anyone would know how much (if more) contact area the M3 brakes have vs the 335s. i want to do this, but I would only truly consider doing it if there is braking performance to be gained.

[06E90Rostik]

Re: friction area

I doubt M3's will be bigger. The rotor is bigger, but its also drilled, which means you loose contact area.

If you really want performance, consider just swapping 335 rotors with 2 piece ones from Z4 35is. Same size as 335's so will fit perfectly and better performance in terms of better heat management.

[The HACK]

Originally Posted by 06E90Rostik

Re: friction area

I doubt M3's will be bigger. The rotor is bigger, but its also drilled, which means you loose contact area.

If you really want performance, consider just swapping 335 rotors with 2 piece ones from Z4 35is. Same size as 335's so will fit perfectly and better performance in terms of better heat management.

The "2 piece" rotors from the Z4 doesn't offer any performance benefits except that it's lighter and since aluminum hat does not transmit heat as much, it's slightly less likely to damage the hub due to excessive heat. However, on a car that's doing upgrades PURELY for looks, I would just get some drilled rotors and be done with it.

The bigger rotors on the M3's brakes actually do offer tangible benefits. First, the larger radius will allow the brake to apply torque at a higher multiplication factor. Second, the M3's rotors are true "floating" design, meaning the rotor and the hats are actually physically separated. There's some real performance benefit to having said design. Not only does it decrease weight, it also allow the ring part of the rotor to expand/contract independently of the hub. Plus the separation between the rotor and the hub allow more ambient air to enter the interior rotor vanes to help keep the rotor operating at peak temperature.

Having said all that. The master cylinder and the pressure it supplies from the M3 is different from the run of the mill 3 series. Meaning a swap of rotors, calipers, and carriers onto a 335i will actually DEGRADE brake performance because the 335i can not supply the same pressure to the larger caliper pistons (the calipers may not look any larger, it's the piston area that counts). Swapping M3 brake components to upgrade a 335i's brakes will actually need to include the master cylinder as well.

The most "eye catching" upgrade will still be a big brake kit with 6 or 4 piston fixed calipers. No one will mistake a red or yellow caliper for stock calipers and they do look b*tching. Couple that with some drilled rotors you're sure to catch the attention you desire.

But if you're into real performance upgrade, you just need the 2 piece floating RacingBrake rotors Harold is selling through his website and some better pads.

[Hooy]

I feel you OP, I wish there was an affordable brake size upgrade. Unfortunately the M3 brake swap requires a lot of work and will end up costing more than you wanted.

[e90pilot]

Save your money for now and scope out the user classified section. Someone is always parting out their car and BBKs do pop up from time to time for a good price. They also go fast so be sure to check everyday. You can also put up a WTB thread and hopefully someone will contact you.

[JoeyBananaz18]

Thanks for the depots everyone. I think I may just paint my calipers and look for some cross drilled rotors.

Hack, I've read so many of your posts. The amount of info this forum gets from you is astounding. You must be in some form of engineering.

[The HACK]

Originally Posted by JoeyBananaz18

Hack...You must be in some form of engineering.

Nope. Marketing/designer by trade. Although I did work at an aftermarket manufacturer (up until a few weeks ago, anyway) that makes driveline related parts for 'Merkin muscle cars new and old.

Everything I learned about brakes and suspension I learned from listening to people who REALLY know what they're talking about, and went out to the track and confirmed it.