E46 Big Brake Project

[Cement 860]

Time for another side quest on the E46 !! This time it will be getting some bigger brakes in place of the 330 items currently on there.

The plan is to go with the current recommended setup from https://thebuildjournal.com/tech-guides/e46-m3-bbk-brake-bias-guide-why-the-megane-rs-trophy-r-is-the-best/ which will be using:

• Renault Megane Trophy R front 4 pots with (most likely) M3 CSL spec discs
• Porsche 996 rear 4 pots with M3 spec discs
• Steel rear adapters from creationsmotorsport.com
• Front kit will be from freakyparts.co.uk
• OEM master cylinder initially, will see how it behaves but as it's a 318 item I may swap this out to better suit

Have got the rear calipers and adapters ordered. Calipers were from Douglas Valley Dismantlers in the UK; pictured below.

[Vass 796]

Keen to see how you go with it. Not that I need bigger brakes on mine but keen to take on a similar project eventually. My plan is to go with a simple 135i setup, mostly because it's tried and tested, adapters are readily available and the brakes themselves are relatively easy to come by locally. My main fear being that shipping on such bulky items will be the biggest killer, not awfully keen on dumping several grand on brakes alone. Wonder how 135i brake performance compares to the setup you're going with.

Pretty sure all non-M E46's had the same master cylinder so your 318i one will be the same as on a 330i. From what I've read on the 135i conversion the master cylinder and booster should hold up just fine with the bigger brake setup, so long as they're in good working order. Pretty keen to know whether there are any out-the-box upgrade options out there though.

[Harper 520]

The NAM3Forum guys hate on the 135i setup, supposedly those calipers are a bit junky but maybe that's just in comparison with M3 calipers. Probably still a significant upgrade over the 330 ones.

I've had a set of 996 front and rear calipers sitting in storage for about a year waiting for a rainy day to rebuild and fit to my M3. Almost identical to the OE CSL brake bias with way better pedal feel. The stock brakes honestly are completely sufficient with decent pads and fluid even when I had them on track. I haven't quite been able to bite the $2000 bullet for new CSL front and rear rotors and rallyroad adapter brackets for a mostly visual upgrade but it's on the to-do list.

15 hours ago, Cement said:

Steel rear adapters from creationsmotorsport.com

The brackets from rallyroad are far superior, lighter (about half the weight), higher quality, and allow you to run the 98635193915 D737 shape pad which will sweep the entire M3 rotor, where the stock 98635293910 D738 pad won't.

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/3153-porsche-brembo-996-bbk-conversion - Very good write up comparing the different brackets

Look forward to seeing how you go with this and what your impressions are. 

Edited August 1 by Harper

[Cement 860]

Yea, I've got to be honest in that this is mostly for looks and the fun of wrenching on the car. The additional functionality with some good pads will be essentially a bonus. I was 'not completely shocked' on the freight of the rears which are on the way via TNT / FedEx and paid £295 all done.

As far as master cylinder options go I'd be looking at the M3 item as a replacement since it's what the kits are designed around. Speaking of which the link in my original post is an interesting one if you are looking at the 135i swap as it's (by their measurements / calculations) one of the worst options in terms of bias change ... table below:

I'll take a look at the thread thanks @Harper 👍 Looks like more than my Friday lunchtime read I did look at the Rallyroad brackets but i prefer to see them made from steel to be honest and hence going for the creationmotorsports items. I'll have the Renault calipers on the front so the disc sweep part won't be relevant for me, at least in the context of the thread from what I can see. The freakyparts folks will be designing the non-M kit for me so they should be able to give me some feedback on these aspects on the way through.

[Cement 860]

The couriers are being good to me it seems (at the moment) and I should have the rear calipers and brackets this coming week so I can do a test fitting before sorting out discs and caliper refurbishment etc.

The fronts are a little more complicated when looking at 'good value' options for the rotors. As the folks at freakyparts.co.uk will be putting this kit together I've been looking at the rotor options they currently provide for the E46 M3 kits:

• E9x M3 (360x30mm)
• E46 M3 CSL (345x28mm)

I made up the templates which are available on their web site to check fitment against the wheel and both easily fit with plenty of clearance which is nice (image below). For reference this is in a Work Emotion M8R 18x8.5 ET38. However, I'm sure the E9x rotor will foul the tie rod end and / or the lower control arm around the ball joint. Potentially this is where the M3 king pin / knuckle gets it's extra track width ?? More pics below to illustrate ... another difference that might make it work is the hat thickness being thicker on the E9x where it sits between the hub and wheel 🤔

So options from here for rotors will be (after seeking some wisdom from freakyparts.co.uk after they test fit with the knuckle they are buying):

• E46 M3 CSL (expensive)
• Maybe the E9x M3 will work but it's hella close to fouling ?
• Custom 2 piece using a DBA 5000 series rotor or similar to get the spicy size as well as a 'low offset'

[Cement 860]

Got the rear brackets this morning. They look really good and arrived super fast !!

[Cement 860]

Plenty of progress but not much posting of it lately. Plenty of spicy spam below ...

--- Rear End ---

The used 996 Brembo calipers arrived last week (very nicely packed) and on Friday I picked up the M3 rear rotors (DBA 4000 series) so I could check the fitment before carrying on with anything else.

Some findings / notes through the process so far (most of which can be found on the internet but will echo here for completeness):

• The rear Porsche calipers to get are from 1999-2004 996 (non-turbo), the Boxster S or Cayman S. Part numbers are 996.352.421 and 996.352.422
• Piston sizes on the Brembo calipers are ⌀28 and ⌀30
• Dust boot part numbers are 20 4872 40 and 20 4872 41
• Complete caliper seal kit part number is 143.37009
• You need to use M3 rear discs on either 330 or M3 trailing arms and source the appropriate brackets (Rally Road or Creation Motorsport the most common)
• 330 and M3 parking brake shoes are different widths (20mm on 330 vs 30mm on M3) but the disc drum diameter is the same at ⌀185mm, looks like i can just use my 330 shoes in the M3 disc no problem and upsize them when they wear out
• The M3 and 330 discs are the same overall height (61mm) but the M3 rotor itself is about 11.5mm further inboard (the 330 parking brake drum protrudes from the disc face, the M3 is basically flat)
• The dust shield needs to be trimmed for caliper fitment and flattened out to not foul the disc due to the rotor itself moving. I cut slits in mine (330 items) for now to flatten it back in sections, but this does look pretty average. You need to retain the centre of the dust shield if nothing else as the parking brake shoes mount to it.
• The disc retaining bolt on the 330 vs M3 discs are different, you will need to add this counter-bored hole to the M3 discs to do a nice job of things
• The specified OEM pads for this caliper are the D738 shape but apparently the D737 can also be used and wipes more of the disc (D738 leaves a ring on the inside where the pad does not wipe apparently)
• The OEM caliper cross over pipes need to be changed to the opposite ends of the calipers as they mount to the rear on the E46 and to the front on the Porsches.This maintains the correct piston size stagger (rotor passes the smallest piston first).
• Some other misc measurements which may help somebody for something in the future:
  • Piston size on the OEM 330 rear caliper is ⌀42
  • Rear disc centre bore is ⌀75mm
  • OEM 330 hub flange is ⌀145mm
  • Thickness of DBA rotor hats (where the disc sits on the hub) is 7mm

--- Front End ---

I've identified which direction I'll be going now with the front setup. Going to go for a two piece rotor using 356x30mm DBA disc and aluminium top hat. Still might look at getting the Freaky Parts folks to supply the calipers and brackets / hoses etc but will see now as they may not be interested if there is not wider market appeal.

The reasons for going this way over the CSL discs are:

• I don't want cross drilled rotors, which nearly all of the CSL spec items are
• Call me a snob here but I want front and rear rotors to match

So to that end I've been beavering away measuring my 330 king pin's / knuckles along with my wheel inside profile and getting everything modeled up to a reasonable state.

More random facts and measurements are as below for the front end based on Renault Megane 275 Trophy R Brembo calipers.

• Factory Renault uses disc size ⌀340 x 28mm
• Pad sweep depth of 61mm
• There are numerous options and from what I can tell the correct part numbers for the calipers are 410116043R & 410010873R
• The OEM pad part number is 410603303R
• Calipers use dual ⌀40mm pistons per side
• Some other misc measurements which may help somebody for something in the future:
  • Piston size on the OEM front 330 caliper is ⌀57
  • Front disc centre bore is ⌀79mm
  • OEM 330 hub flange is ⌀140mm

--- Images ---

What you get when you paint the calipers on the car. Factory colour is the grey.

The bracket installed, there is the slightest interference with the bolt head for the upper control arm. Literally needs a couple of passes with the file.

Trimming the dust shield in line with the bracket mounting face.

Test fitting the caliper. Note the slitting of the dust shield so it could easily be flattened out. I will likely trim this to the disc size so you can't see my handiwork here.

This is showing the pad sitting slightly away from the hat on the rotor, which is apparently solved using a slightly larger pad.

A good illustration of the difference between the M3 (left) and 330 (right) discs. You can clearly see the parking brake drum protruding on the 330 item.

Setting up the 'coordinate system' for measurements of the front caliper mounting in relation to hub centre. This is using a laser level and ruler taped onto the hub face which is set level. Here I am running the laser straight along the ruler edge so i can establish exactly where 90 degrees is to it so my measurements are all nice and square.

... then I can establish my 'zero offset' using the ruler measurements. Strange how the laser looks like a chalk line in the pictures

An example of measuring the mounting hole positions using this technique. I'd estimate accuracy of +/- maybe 0.5 - 1mm which will be good enough to prototype using the 3D printer, or to validate against known good values from an M3 to see what is the same and what is different etc.

Had to cut off the bridging pipes to be able to remove with a proper socket as the flare wrench was making a mess of things.

Pistons and dust boots removed ready for some paint stripping and cleanup prior to painting.

A couple of shots from the 3D modeling of the front setup. It's not meant to look flashy but represent accuracy where it's needed. I neglected to get pictures of taking the measurements of the inside wheel profile (spokes), but involved the same ruler sitting square and centres on the wheel mounting face then taking 'drop' measurements every 10mm. It worked out really well when you look at the reproduced contour.

 

[Cement 860]

A bit of a photo montage of cleaning up the calipers. First time using this gel based stripper and the first application I had not shaken the bottle enough so it was a bit too thin instead of a gel that would sit on the surface with some thickness to it. Overall the process to get to this point was:

• Roughen up where the stripper would be used
• Brush on the paint stripper, wait a while then hosed off
• Used compressed air to blast off / lift additional paint which was lifted but hanging on
• Use stiff plastic bristle brush to further loosen anything you can
• Another roughen up with sand paper and then re-application of stripper
• Dry off with compressed air
• Carefully scrape off any softened material with screwdriver or chisel
• Reinstall sacrificial dust boots, bleed nipples and stuff rags into the pistons
• Sand blast any remaining bits of paint, corrosion etc

If doing again I would have gotten a finer garnet (I got Toolshed 'medium') as even my shitty Aliexpress blaster gun was actually pretty good ... I think it'll be fine with primer then 2k single stage paint I've gotten.

[Cement 860]

Got some parts today from FCP Euro for the rear caliper reconditioning. Turns out the cross over pipes are actually different left to right side !! Gutted.

Part numbers for those interested are:

• Cross over lines 99635296102 and 99635296200

• Pad wear sensor 99661236500

• Pad retention kit 99635295901

• Bleeder screws 93035191900

• Caliper mounting bolts 99907340201

[Cement 860]

Perfect weather to get these rear calipers painted this weekend. Started off with a sand down with 360 grit to ensure the primer had something to bite into. Then a double wash in wax & grease remover. I should have gone for a hot soap and water scrub first in hindsight.

Installed the old dust boots and stuffed rags into the piston bores to keep the paint out. For the bleeder, cross over pipe and inlet I used trimmed down foam ear plugs Saw that in a YouTube video and it works perfectly !! Taped over the mounting surface so it's not sitting on paint.

Painting was two coats of 'Paraloc' etching primer, then two coats of 2k single stage polyurethane. I did this 'wet on wet' at the suggestion of the folks at the paint place, so I did not have to wait for the primer to harden and then sand it ... definitely gets my vote as sanding calipers properly would be horrid.

[Eagle 1653]

Didn't like the original gold colour?

[Vass 796]

Bold color choice indeed

[Cement 860]

2 hours ago, Eagle said:

Didn't like the original gold colour?

 

1 hour ago, Vass said:

Bold color choice indeed

🤣 Thought everybody liked blue and yellow !! Question is now should I leave the fronts red hah

[Eagle 1653]

I honestly thought you were running a blue gold theme. Suppose the subframe bushings will have some company now haha.

[Cement 860]

You know I'm actually aesthetically challenged I think, never even occurred to me that i have blue / gold anodised fittings in the engine bay 🤣 Story will be that you have to look at the car from below for the theme to make sense hah

[Cement 860]

I've baked the painted calipers in my 3D printing enclosure, ramped up to about 60 degrees and let them cook for a few hours. This has hardened up the paint nicely and they look great

The front Meganne calipers arrived today right on time, ordered them from https://eurofrance24.com based out of Poland and was a very smooth experience. Came in under the GST / duty threshold which was great ... still need to get the pin kit and bolts etc from else where.

3D printed some dummy brake pads which I will use to validate the rear before ordering (as looking to use the deeper D737 profile pads) and the fronts will be critical for caliper mounting bracket design.

Also printed out a small jig for drilling the rear M3 disc location set screw hole to suit my 330 rear hubs. On the other side of the starfish there are 5 nubbins which locate into the disc holes.

[hunter 407]

On 8/25/2024 at 9:25 PM, Cement said:

Perfect weather to get these rear calipers painted this weekend. Started off with a sand down with 360 grit to ensure the primer had something to bite into. Then a double wash in wax & grease remover. I should have gone for a hot soap and water scrub first in hindsight.

Installed the old dust boots and stuffed rags into the piston bores to keep the paint out. For the bleeder, cross over pipe and inlet I used trimmed down foam ear plugs Saw that in a YouTube video and it works perfectly !! Taped over the mounting surface so it's not sitting on paint.

Painting was two coats of 'Paraloc' etching primer, then two coats of 2k single stage polyurethane. I did this 'wet on wet' at the suggestion of the folks at the paint place, so I did not have to wait for the primer to harden and then sand it ... definitely gets my vote as sanding calipers properly would be horrid.

love the yellow!

 

[Karter16 390]

Yep that yellow is spot on - looks awesome!

[Neil McCauley 390]

On 8/26/2024 at 4:09 PM, Eagle said:

I honestly thought you were running a blue gold theme. Suppose the subframe bushings will have some company now haha.

If the brakes were still gold some cheeky 555 stickers wouldn't go amiss!

[Eagle 1653]

Be interesting to see what they look like mounted thats for sure

[Cement 860]

Doing plenty of things lately in the background:

• Design work and validation of some aspects via 3D printed prototype parts
• Looking at the technicalities of brake bias and where my combination will sit
  • Got a book which is well regarded "High Performance Brake Systems"
  • Messed about a little with some online calculators and a Google sheet based one
  • Trying to work out if the bimmers have a tandem, stepped or tandem stepped master cylinder and if that really has any bearing on the line pressure / bias etc etc ... bit of a mine field, need to read more of the book !! Same goes with proportioning valve and my E46 in particular which is ASC only.
• Looking at disc mounting options, might try and do a fully floating system instead of a rigidly bolted hat
• Trying to knock some cost out of having to get custom parts machined Anybody want the same kit for their non-M ?

This is what 7 hours of printing looks like !! Had to do it with enough resolution that the printed threads are functional.

I have more clearance than my measurements said I would which is good news !!

Also made this wacky little part to validate my laser level based measurements of the mounting holes relative to the hub. I was about 1mm out, this is the mk2 design. I'd still like something more accurate and have my thinking cap on 🤔

[Eagle 1653]

Ive taken apart an E39 one which id class as a stepped tandem master cylinder, presumably the E46 would have the same design but M3 one may vary in diameters compared to non m.

Have you looked at the price on an M3 master cylinder?   

[Cement 860]

On 9/4/2024 at 4:20 PM, Eagle said:

Ive taken apart an E39 one which id class as a stepped tandem master cylinder, presumably the E46 would have the same design but M3 one may vary in diameters compared to non m.

Have you looked at the price on an M3 master cylinder?   

Yuuuuur from the research I've done:

• My OEM 318 is 22.2 / 20.6
• 330 is 23.8 / 22.2
• E46 M3 is 25 / 20 with MK20 ABS and 25 / 22 with the MK60 (these look like approximate sizes, likely 1" in reality etc)

So I'll likely have a look around once I know what sort of front to rear size ratio will work best for my setup. Have located TRW M3 for a non insane price

Printed off a rotor hat so i can do more fitment mockups / validation, only just fit on my printer bed and took about 16 hours !!

I then added a portion of the rotor and glued them together ... too keen to get it glued up and neglected to ensure it was nice an square so may turn out to be of limited use 😕 Might do another one for the other side over the weekend and ensure i do it properly.

Picked up the result of my thinking cap time also and am really pleased with how these worked. This was to validate more accurately (than my 3D printed 'jig') what i had measured with my laser level. What I'm measuring here are the offset front to back as well as depth of the caliper mounting holes in the knuckle vs the centre. Attached is my high tech engineering drawing if anybody wants to replicate 😆 

Worked out really well, and proved the 3D printed jig was only about 0.2mm out front to back !! From memory there was a previous 1mm variation between the laser measurements and the 3D printed jig also. Shout out to James Simpson Engineering who turned these for a very reasonable in 2024 $40.

I should point out that while the 3D printed jig was a good fit when on the car it was essentially impossible to measure the 'as built' dimensions of the plastic part. I'm being pretty particular here as I'm in no hurry.

[Cement 860]

Got the front rotors ordered and should be here in ... November

Validated the fitment with all the printed parts and all looks well. Happy to press ahead with the manufacturing from a fitment perspective ... just not a budget perspective. Yet another project that's really stacking up far more than expected.

Got my rear caliper seals installed. Supplied by US Procurements if anybody else is in need of Brembo seals. Also installed the new bleed nipples and the cross over pipe which I have (need to get the other side still).

 

[adro 1075]

This thread is so next level, thanks for sharing!