And now fitted to the car.
One thing I didn't think would be an issue is wheel clearance.
Offset with my wheels is fine but it's the actual inner barrel of the wheel that is incredibly tight.
I also had to make some clearance on the trailing arm as the bracket and bolts interfered which i have noticed across 3 different trailing arms to be different, clearly something in the casting of the trailing arms.

Handbrake works perfectly with same adjustment as with the stock disc given its the same 160mm size.

Disc retaining bolts line up and you can use stock e46 disc retaining bolts.

E46 stock pad wear sensor fits the pad.

Hel brake lines E46 M3 to F8x brake lines fit perfectly.

Lots of choice of pads available as they share the same pad as the M3/M4. I'm using Ferodo DS2500 pads.

I'm using a one piece disc currently for the trial conversion but BMW use a 2 piece construction from factory to save weight and 2 piece floating discs are also available.

 

So with the rears complete on to the front.
Using the M140i/F30 340mmx30mm discs and 4 pot brembos 40mm piston.

Calipers bolt straight up to the knuckle no problem.

Discs, there are a few options.

CSL 345mm bolts straight on but has the wrong swept area and requires 14mm cutting off the pad and the cost of CSL discs is ridiculous for essentialy the wrong fitting disc!

VW T6 340mmx32mm van disc requires the centre bore enlarging to 79mm and the disc retaining screw hole drilled and not to mention the weight of the disc! They are seriously heavy and have a 10mm thick face which will space the wheels out by 3mm.
Will also require Shims for the caliper to sit central.

Mercedes A45 AMG disc, requires the pcd re drilling to 5x120, the centre bore enlarging to 79mm and the disc retaining screw hole drilled.
Will also require Shims for the caliper to sit central.

All these options require modification every time you want to change pads (CSL) and discs (VW & Mercedes)

I have opted to use the F20/F30 340mm x 30mm disc and have a custom spacer made.

I used a 25mm off the shelf hubcentric wheel spacer and had it machined to locate on the hub where the disc would usually locate and also sits on the wheel hub snout, so it locates on both with a tight fitment, I then had the disc location machined into the front of the spacer to centralise and locate the disc like factory and the disc locating screw drilled to secure the disc and spacer.

Spacer, once machined to locate the disc is 18mm thick behind the disc.

I then had the caliper lugs machined down 2mm which isn't a lot given the amount of meat on the calipers.

A 20mm spacer would be perfect behind the disc so the caliper wouldn't need modifying but I really didn't want to space the disc any further out as wheel stud length would begin to be a problem and the offset with my wheels would also be tight to the caliper and arch.

The spacers are also completely interference free of the studs.

With that all machined it's a simple bolt on brake kit with pads and discs remaining untouched for future disc and pad change.

No modifying the brake dust guard.
Stock caliper bolts can be used.
Correct pad swept area.
M3-F8X Hel brake lines fit perfectly.
Pad wear sensor fits although could be a fraction longer.
Disc retaining bolts need to be longer. I used a 30mm stainless steel counter sunk bolt so it can be re used.


Pictures on next post.

 

 

My wheels are:
18x8 et40 225/40 front.
18x9 et31 255/35 rear.

The front wheels have a few mm clearance to the spokes of the wheels and a few mm to the inner barrel of the wheels so it's very close all round.
The rear has lots of clearance to the spokes of the wheels but again only a few mm to the inner barrel of the wheel.

This is the biggest brakes that will fit these CSL rep wheels, 19s would be needed to go any bigger.

Hope this helps others out and once fully bedded in and tested I will report back.

 

Just an update.
Covered a thousand miles now and zero problems, with the Ferodo DS2500 pads bedded in what a difference! So much more confidence in late braking, braking force has definitely improved and keeps on giving the more you push on the pedal and no pad fade due to lack of disc size anymore.
Pedal feel is greatly improved and I would say the same amount of pedal travel as the stock brakes which was my main concern having read other threads on the brake swap.

Very happy with the swap and love the look of the OEM appearance which was my aim with this kit along with reducing brake fade.

 

Another update with another thousand miles covered.

Brakes are working flawlessly!
Did a full check round everything and all is well, everything is still tight and where it should be.
Have had no adverse affects with the front discs being spaced, no wheel wobble at speed even at over 150mph, wheel nuts have not become loose etc as I'm sure some will be sceptical about the spacer but if done right it's fine.

Pedal travel hasn't altered and is almost the same as stock and doesn't affect heel toe braking so I'm chuffed with that.

I will be looking into having more rear brackets made up as I get contacted daily about them and have them drawn up to pass on to members .

I will also be looking into a true 2 piece floating disc setup for both front and rear so I can ditch the cheap heavy Mtec discs i used initially in favour of some billet bells and true floating discs.

 

Hi @R11CH, firstly thanks for the guide. I’m planning to do a very similar route myself.

I’m interested by your recent comments on floating rotors and have some questions.

1) Whats wrong with an off the shelf F30 2 piece offering like Paragon? Price?
2) Can you explain which i3 rotors you are talking about?
3) Comp motorsport sell 340mm rotors without bells for £340. I would expect it wouldn’t take me long to design a bell. A custom bell would allow us to edit the hat height, and possibly remove the need for a spacer behind the front discs. I understand most wheels would then still need a spacer outside the disc, but that is more preferable as it allows the use of lower offset wheels!

The comp rings were the first I saw, but if going down the custom bell route, there are audi etc rotors with the similar dimensions which may be cheaper! (If they have the right sweep face etc.

 

1. Paragon is probably the route I would go down for off the shelf. Genuine BMW off the shelf discs are pretty good and light weight but not a true 2 piece and the single piece disc I currently have are heavy and no vane technology.

2. I can't remember exactly which model but they use the same 340mm caliper and 340mm discs, they are 2 piece construction the same as the f30, the hat height was definitely lower but would still have required a spacer something like 5mm-6mm which I couldn't make a spacer that small and retain the hubcentric side of it all. I couldn't find any used in the UK only Poland on ebay so i messaged a few and one got back to me with the size and hat height. They weren't cheap even though they were used hence why I didn't take the gamble and try them.

3. I contacted a guy who makes brake kits for a living and he couldn't find any rings off the shelf with the same pad swept area, was a few close but still 6mm out so the pad would need cutting. He said the pad swept area is fairly large and the bell very small which makes it difficult and taking a look at paragon you can see there isn't much meat for fixings well as most bbk have a larger bell and smaller pad swept area.

Definitely a custom bell would be the answer with the same hat height as the csl disc although I have never looked into if the disc sits central in the caliper and as the csl disc is 28mm thick you can get away with it being off central so that would need looking in to but yes the spacer behind the disc isn't everyone's preferred method I know.

 

So a year later and a few thousand miles covered, all is well and working perfectly.
Nothing has moved regarding the spacer or rear bracket, pedal feel and travel is the same as stock but with added bite and no brake fade.

Love the way they look and perform!

 

Hi, I’ve just completed a brakes swap on my E46 320Cd from those factory tiny ones to F30 4 piston 340mm ones and rear F20 2 piston 345mm.

However I’ve made few changes.
In front instead of using factory discs and 18-20mm spacer behind the disc I’ve used Brembo 09B91311 discs. Because of that I also had to add 2mm spacer between the hub and caliper to center the caliper.

In the rear I’ve made custom bracket to fit the caliper just like you but I also had to add 6mm spacer behind the disc to center the disc and caliper. I do believe that yours disc is just located deeper then mine and this is something that I may reconsider.

So everything went smoothly until I started fitting wheels. In the rear I’ve successfully mounted styling 228 8x19 et 37. They are sticking out a little bit but they will do and I know that everything from 17” x 8 et 37 will fit.

However front wheels are driving me crazy. They always sticks to far out or they rub against the caliper.

Would u mind shearing where did u get you wheels and what brand they are? I do believe that my problem mainly comes from the wheel design and that’s why I’m looking for something else to fit.

Maybe somebody else has done this swap and can share some informations.
Right now I’m thinking about BBS CH-R 18x8 et40 or some csl replicas. But the only one I’ve found are AVUS AC-MB4 8x18 et 43, and I can’t find any reviews of them.

 

I have swapped those 4pot calipers into my e46. With e46 M3 CSL rotors. No spacers between rotor and hub. But had to add 20mm spacer between rotor and disk, so my standard factory 135 style will fit.

 

 

Another year another few thousand miles covered including a 1200mile euro trip to the Nurburgring, car was faultless and the brakes were amazing to say the least, never found the limit of the brakes just took all the abuse I could throw at them and even the Mtec disc surprised me as most complain of warping them but again perfectly fine.