BMW E46 Fanatics Forum banner

1 - 20 of 73 Posts

·
Banned
Joined
·
187 Posts
Discussion Starter #1 (Edited)
First off let me say that this thread is not meant to bash anyone or anything, it is meant purely as a reference. Seeing as I do not own every single E46 ever made I cannot 100% guarantee a single solution will work for you, the best I can do is cross reference part numbers. Please avoid filling this thread with questions like "Why would you want to do ___ when you can do ___?" as well as any other non related topics. If you notice an error please let me know so I can correct it. I will not be making specific pad, rotor, or fluid recommendations because everyone uses their car differently. Track pads are probably not ideal for someone who dailies their car, and some people prefer one style of rotor to another. I will do my best to include links where applicable. The last thing I have to say is PLEASE BUY QUALITY PARTS. Yes, eBay rotors and pads may get you down the road but it's your life, your car, and your money. Let's get started!

For Non-M Cars Only!

Stage 1 - For All Cars

  • New pads and rotors meant for how you drive your car (street, track, autocross, etc...).
  • Flush the system with DOT 4 or higher fluid.
  • Replace rotor screws anytime you remove old ones. They're so cheap it's not worth the hassle of having old, stripped screws.
  • Replace wear sensor. Not needed every time you touch the brakes, but it is a good thing to consider depending on the age and mileage of your sensor.
  • (Optional) Stainless Steel Brake Lines. Not needed, but will give you a slightly improved pedal feel.
  • (Optional) Speed Bleeders. Not needed, but allows the brakes to be bled quickly and you don't need a second person do do them. Worth every penny - http://www.speedbleeder.com/
Stage 2: 330i/ci/xi Upgrade - For 323/325/328 Cars

17" Wheels required. Front rotor size: 325mmx25mm. Rear rotor size: 320mmx22mm.



This process is the same as a standard brake service, however instead of putting your old parts on you replace them with parts from a 330i/ci/xi.

  • 330 Calipers
  • 330 Caliper Carriers
  • 330 Pads
  • 330 Rotors
  • 325xi/330/M3 Wear Sensor - The part number is different between the 325i/ci and the 330. The part number is the same between the 325xi and the 330. I cannot confirm if it is indeed different, but again it is good to replace anyways.
  • Flush the system with DOT 4 or higher fluid
  • 325/330 Rotor Screws
  • (Optional) When doing the rear, you will lose the parking brake functionality unless you swap the rear trailing arms and hub assembly from a 330 because the parking brake shoes are larger. With a 325xi you already have the larger 330 sized parking brake so this does not apply to you.
  • 330 Stainless Steel Brake Lines. Not needed, but will give you a slightly improved pedal feel.
  • (Optional) 330 Speed Bleeders. Not needed, but allows the brakes to be bled quickly and you don't need a second person do do them. Worth every penny - http://www.speedbleeder.com/
Stage 2.5: M3 Upgrade - For All Non-M Cars

17" Wheels (M3 Rotors) -18" Wheels (CSL Rotors) required. Front rotor size: 325mmx28mm (M3) - 345x28mm (CSL). Rear rotor size:327x20mm.

This process is similar to the 330 upgrade, but requires some machining.





  • M3 Calipers
  • M3 Caliper Carriers - SPINDLE MOUNTING TABS MUST BE MACHINED 6.35mm
  • M3 Pads
  • M3 Rotors
  • 325xi/330/M3 Wear Sensor
  • Flush the system with DOT 4 or higher fluid
  • M3 Rotor Screws
  • (Optional) When doing the rear, you may have to swap the entire rear subframe/differential assembly from an M3. You may only need the 330 trailing arms and hub assembly because the 330 and the M3 share the same parking brake, but there is no solid information about this available.
  • M3 Stainless Steel Brake Lines. Not needed, but will give you a slightly improved pedal feel.
  • (Optional) M3 Speed Bleeders. Not needed, but allows the brakes to be bled quickly and you don't need a second person do do them. Worth every penny - http://www.speedbleeder.com/
Stage 3: Porsche 996 Upgrade - For All Non-M Cars

17" Wheels (M3 Rotors) -18" Wheels (CSL Rotors) required with +35mm offset or lower. Front rotor size: 325mmx28mm (M3) - 345x28mm (CSL). Rear rotor size:327x20mm.

This process is similar to the 330 upgrade, but requires some grinding/machining and minor wiring. The wear sensor wires must be spliced between the 996 sensor (pad side) and the E46 sensor (vehicle side).





  • Porsche 996 Front Calipers (PN 996.351.425, 996.351.426) - Machine mounting bosses 12mm for use with M3 rotors, do not machine for use with CSL rotors
  • RallyRoad Front Caliper Brackets - http://www.rallyroad.net/content/e36-and-e46-non-m3-brackets-porsche-996-calipers
  • Porsche 996 Rear Calipers (PN 996.352.421 996.352.422)
  • RallyRoad Rear Caliper Brackets - http://www.rallyroad.net/content/e36e46-non-m-rear-brembo-brackets
  • Porsche 996 Pads
  • Porsche 996 Pad Shims - These prevent the brakes from squaking like many people complain about. Not needed, but cheap enough to not skip over.
  • RallyRoad Front Brake Lines - http://www.rallyroad.net/content/e46-big-brake-kit-front-lines
  • RallyRoad Rear Brake Lines - http://www.rallyroad.net/content/e46-bbk-stainless-rear-brake-lines
  • M3/CSL Rotors - Read above
  • 325xi/330/M3 Wear Sensor
  • 996 Wear Sensor
  • Flush the system with DOT 4 or higher fluid
  • M3 Rotor Screws
  • Grind casting marks on the spindle - This will vary between vehicles. On some (most?) you will need to grind away the casting lines on the spindle so that the caliper bracket sits flush. It is nothing major, but it does need to be noted.
  • (Optional) When doing the rear, you will lose the parking brake functionality unless you swap the rear trailing arms and hub assembly from a 330 because the parking brake shoes are larger. With a 325xi you already have the larger 330 sized parking brake so this does not apply to you.
  • (Optional) 996 Speed Bleeders. Not needed, but allows the brakes to be bled quickly and you don't need a second person do do them. Worth every penny - http://www.speedbleeder.com/
Stage 4: 135i Upgrade - For All Non-M Cars

17" Wheels required with +35mm offset or lower. Front rotor size: 325mmx25mm (unless using ECS kit or custom brackets). Rear rotor size:327x20mm.

This process is similar to the 330 upgrade, but requires some cutting and minor wiring. The wear sensor wires must be spliced between the 135i sensor (pad side) and the E46 sensor (vehicle side).





  • 135i Calipers
  • 135i Caliper Brackets. Stock caliper brackets will leave a little bit of pad overhang. Not 100% ideal, but will work fine. Currently the only solution is to buy the whole kit from ECS tuning or have custom brackets made.
  • 135i Pads
  • (Unsure) Extended Front 135i Brake Lines - Stock 135i lines MAY work. Not sure on where to get these other than having a set custom made, need to be 600mm long. Front 135i lines can be used on the rear to possibly solve the rear length issue if needed.
  • 330 Front Rotors
  • M3 Rear Rotors
  • 325xi/330/M3 Wear Sensor
  • 135i Wear Sensor
  • Flush the system with DOT 4 or higher fluid
  • 330 Rotor Screws
  • M3 Rotor Screws
  • Trim/replace rear dust shield - In order to clear the M3 rotor on the dust shield must be trimmed or replaced with an M3 shield.
  • (Optional) When doing the rear, you will lose the parking brake functionality unless you swap the rear trailing arms and hub assembly from a 330 because the parking brake shoes are larger. With a 325xi you already have the larger 330 sized parking brake so this does not apply to you.
  • (Optional) 135i Speed Bleeders. Not needed, but allows the brakes to be bled quickly and you don't need a second person do do them. Worth every penny - http://www.speedbleeder.com/
  • (Optional) The stock 135i caliper pistons are prone to cracking under hard (read:track day bro) use. Replace with a quality set of pistons.
I will update this thread as I find time. I hope this is a good start for some of you, and I hope it's good enough to not be deleted right away. Every other forum I've been on has had guides like this posted, but I have not found very many on this forum. PLEASE SEND OR POST PICTURES OF YOUR BRAKES!!!
 

·
Registered
Joined
·
8,016 Posts
A great contribution to the forum. :thumbsup:



Rob43
 

·
Banned
Joined
·
187 Posts
Discussion Starter #3
I've slapped together pretty much everything I could think of besides the obvious off the shelf Brembo or Stoptech kits. Should be a good place to start.
 

·
Registered
Joined
·
209 Posts
Also, you can use the f30 rear calipers with the e46 330i carriers. Why do this you ask? I had a set of take off f30 calipers, and horrible scaly 330 calipers. The only sticking point is that you will need a 90 degree adapter as the f30 line goes straight into the caliper, whereas the e46 goes at a angle.

Piston size

model ext internal
325i 38.1 19.8
330i 41.1 24.6
f30 40.5 29.5
 

Attachments

·
Banned
Joined
·
187 Posts
Discussion Starter #5
Also, you can use the f30 rear calipers with the e46 330i carriers. Why do this you ask? I had a set of take off f30 calipers, and horrible scaly 330 calipers. The only sticking point is that you will need a 90 degree adapter as the f30 line goes straight into the caliper, whereas the e46 goes at a angle.

Piston size

model ext internal
325i 38.1 19.8
330i 41.1 24.6
f30 40.5 29.5
Is there any advantage to doing this? Bigger rotor, bigger pads, more clamping force, anything?
 

·
Registered
Joined
·
209 Posts
Is there any advantage to doing this? Bigger rotor, bigger pads, more clamping force, anything?
It would fall along the same lines as the 330i upgrade for the 325is. Not sure if the small difference in piston sides would correlate to a difference in clamping pressure. The calipers are a different design, but I am not sure if they are more stiff or not (which could increase clamping force). I just happened to have all the parts so I figured I'd try it. Also, Im running m3 brakes up front but with a stock MC
 

·
Registered
Joined
·
209 Posts
Well I thought about going to a M3 MC as the piston size is different, but I haven't noticed any issues with pedal feel or travel. Granted I don't track my car and the upgrades are more cosmetic than anything.
 

·
Ironman
01 330iT 6MT, 98 M Roadster
Joined
·
4,946 Posts
What fits and all is nice, but that's not the whole enchilada as it were.

First of all, when changing the braking system, you're probably changing the bias, especially if doing the fronts only.

When upgrading from say a 325 to a 330, the change should include a MC change (as well as changing both front AND rear components) to keep the system balanced.

There are formulas that can be used to keep the system working efficiently and effectively. Of course, once and throw darts at a board and randomly hope for a bulls-eye. I've never needed to do the calculation as I've only changed out the braking components on one car (one platform actually - multiple cars) and the change actually improved the braking overall. It's entirely possible to increase braking distances if you install powerful front calipers/pads/rotors without changing the rears and/or the MC. The reason for this is you could easily throw the bias towards the front of the car with little effective braking from the rear. It's great for confidence, but not necessarily for overall performance.

Racing brake set-ups have adjustable bias, either through a proportioning valve or dual MCs (one front, one rear) with a bias bar that allows adjustment between them.

I would imagine throwing 996 brakes on a 325 would mess up bias in a big way.
 

·
Ironman
01 330iT 6MT, 98 M Roadster
Joined
·
4,946 Posts
Well I thought about going to a M3 MC as the piston size is different, but I haven't noticed any issues with pedal feel or travel. Granted I don't track my car and the upgrades are more cosmetic than anything.
Feel and travel are certainly important, but so is bias, which is quite often overlooked.
 

·
Registered
Joined
·
209 Posts
Master Cylinder Sizes

325/330 Front 22mm Rear 20mm
M3 Front 25mm Rear 20mm

325i Rotor 300x22
330i Rotor 325x22
M3 Rotor 325x28

With that we can deduce that the 330i will have the highest front bias of the three. It seems that BMW designed the M3 to have more of a neutral braking setup as well. As I am using the smaller MC, I should be at about the same level of front to rear bias as a stock 330. The rear calipers of the f30 seem to be more rigid, but I cannot be sure. I can run the math but I really dont feel like it right now :)
 

·
Ironman
01 330iT 6MT, 98 M Roadster
Joined
·
4,946 Posts
Don't forget the area of the pistons in the calipers.

My main point is that we need to look at more than just what calipers and rotors can be bolted on if we want an efficient and effective braking system.

[edit] BTW, no disrespect meant to the OP or any contributor here. It's a nice solid start and creates a great depository for info.
 

·
Registered
Joined
·
209 Posts
FRONTS
m3 front 60mm = 2826mm sq total piston area per caliper
330i front 57mm = 2550mm sq total piston area per caliper


m3 setup (stock) ~420 ft lbs of torque
330i setup (stock) ~488 ft lbs of torque
m3 brakes on smaller MC ~541 ft lbs of torque
CSL (since they use the m3 caliper) ~ 446 ft lbs of torque
(All assume 60 lbs of leg force)


REARS
m3 rear 42mm = ~324 ft lbs
330i rear 42mm = ~324 ft lbs


BIAS
M3 Stock 56% front 44% rear
330 stock 60% front 40% rear
m3 on small MC 62% front 38% rear
CSL 58% front 42% rear **Interesting**


Now granted you are correct that my current setup has more front bias than stock, so I will go through pads more often. I don't track my car, and Ive also increased the tire width in the front (255mm) so I have more friction to play with. Something else that might be interesting to think about is since mine is a touring, how does the additional rear weight affect brake bias :)
 

·
Ironman
01 330iT 6MT, 98 M Roadster
Joined
·
4,946 Posts
Beyond going through front pads more often, your rear brakes won't contribute as much to the braking process.

More to the point, as I said before, one need be careful with upgrades. Just throwing large calipers and rotors on the front of a car may not actually improve anything (people could argue over looks).

Believe me, I'm all for improved braking. :)
 

·
Banned
Joined
·
187 Posts
Discussion Starter #15
What fits and all is nice, but that's not the whole enchilada as it were.
That's the point of this thread, trying to round up as much information as possible!

First of all, when changing the braking system, you're probably changing the bias, especially if doing the fronts only.
I was implying to do both the front and rear, but I'll add a note for that. The percentage of people that actually track/autocross their cars here is pretty low so it shouldn't be an issue for most.

When upgrading from say a 325 to a 330, the change should include a MC change (as well as changing both front AND rear components) to keep the system balanced.
From what I see on RealOEM, all of the Non-M cars have the same booster/MC, and the M3s have a different booster/MC. The M3 MC has 2 additional holes in it, maybe because it has a different stability control system? The boosters looked to use the same mounting/attachment from M to Non-M so that might be a place to start. Interestingly enough, the xi cars have a different MC than the RWD cars.

I would imagine throwing 996 brakes on a 325 would mess up bias in a big way.
With the fronts only, I noticed that the fronts will obviously lock up far before the rears. There was also more front end dive, again for obvious reasons. Under hard braking the car still stays straight though, it does not get squirrely at all. With all 4 corners the car just kind of squats all around, fronts still lock up before the rears but just barely. With both configurations the pedal did feel a little softer than OEM (bled with speed bleeders). I kind of prefer this because there's less initial bite and makes it easier for me to modulate the pedal. I autocross about twice a month, give or take. Not sure if RallyRoad did any calculations for brake bias, but the setup seems to work pretty well. The 330 swap is probably enough for anybody except a dedicated balls to the wall track car, but that's not the point of this thread.
 

·
Ironman
01 330iT 6MT, 98 M Roadster
Joined
·
4,946 Posts
That's the point of this thread, trying to round up as much information as possible!
:thumbup:

I was implying to do both the front and rear, but I'll add a note for that. The percentage of people that actually track/autocross their cars here is pretty low so it shouldn't be an issue for most.
The point is, why "upgrade" brakes if you harm the overall braking ability? Doesn't matter the environment. But yes, if upgrading, do it as a system in most cases.

From what I see on RealOEM, all of the Non-M cars have the same booster/MC, and the M3s have a different booster/MC. The M3 MC has 2 additional holes in it, maybe because it has a different stability control system? The boosters looked to use the same mounting/attachment from M to Non-M so that might be a place to start. Interestingly enough, the xi cars have a different MC than the RWD cars.
I'd guess a little more forward bias due to weight distribution with the AWD system as it relates to the xi. I didn't know that the same MC is used for all RWD non-M. Good to know and good info to have here.

With the fronts only, I noticed that the fronts will obviously lock up far before the rears. There was also more front end dive, again for obvious reasons. Under hard braking the car still stays straight though, it does not get squirrely at all. With all 4 corners the car just kind of squats all around, fronts still lock up before the rears but just barely. With both configurations the pedal did feel a little softer than OEM (bled with speed bleeders). I kind of prefer this because there's less initial bite and makes it easier for me to modulate the pedal. I autocross about twice a month, give or take. Not sure if RallyRoad did any calculations for brake bias, but the setup seems to work pretty well. The 330 swap is probably enough for anybody except a dedicated balls to the wall track car, but that's not the point of this thread.
I agree that the 330i upgrade is a nice easy upgrade path. With big 4-pot fronts and larger rotors, a larger rear system would likely be a good idea. I wouldn't expect either end to lock up with ABS. :D

The reason for the softer pedal is almost certainly due to the larger brake piston area when using the stock MC. I would think with a stock MC that the 330i brakes would be nearly unnoticeable, but bit 4-pot calipers would almost certainly yield a softer pedal.

This is good work. As I said, I'm not trying to diss your thread at all. Just pointing out that for truly upgraded braking performance, there are other factors to consider.
 

·
Banned
Joined
·
187 Posts
Discussion Starter #18
After looking at some diagrams, the M3 and Non-M boosters might be interchangeable, minus one part. The Non-M boosters have 2 vacuum ports where as the M boosters only have one. This could easily be fixed with a T fitting, but they look to be about the same. I'd have to have them both in hand to get a real comparison.
 

·
Registered
Joined
·
552 Posts
Has anyone noticed the left side of the brake pedal (least likely to be pressed since your right foot is used for gas, transitioned over to left side of the footwell for brake) on the e46 stops more of the front of the car (or 60-40 split), meaning the more center to center left you move your foot to modulate the brake pedal, the more direct contact path for the four wheels your braking power is distributed to.

Example:
Brake using the right part if the pedal closest to gas and the bias is more towards rear.
..But brake closest to the center to left side (horizontally speaking) of the brake pedal, and more 50/50 or even (since 330 is front bias) application is applied.

I doubt this is just me, can anyone confirm? Or is this just another 'its just my imagination' moments
 

·
Ironman
01 330iT 6MT, 98 M Roadster
Joined
·
4,946 Posts
Uh, it's your imagination.
 
1 - 20 of 73 Posts
Top