F8X Brembo BBK Swap on E46 M3

[YoitsTmac]

Hey everyone, long time lurker but registered. Was hoping for some help with this because I feel really stumped. I plan on doing this on my 330 (overkill yes but I have big power plans in the next year) and need some help with the bias when only doing F80 fronts. I feel the M4 rears is just overkill.

I'm looking for some in-between solution for my non-M rear axle, but am coming short. There's the 135 rear calipers but the table here implies the piston specs of 135 rear calipers are similar to the GT3 rear calipers, and then this calculator here implies that the bias will be closer to 70/30. The chart here on post 52 also states that the rear piston on my car is the same as a stock M3. Also interesting is that the E46 non-M master cylinder is the most neutral of all. The rest of the calculations don't factor disc diameter so don't mind the calculations. I am also running 255 square on 240TW tires with 8k/10k springs. Any advice would be appreciated

[Johnvu]

I'm not registered on M3Cutters but I will if I have to, before I do, has anyone gotten ahold of OP there and is he still selling the rear brackets? If you have an email address even better.

I have a spare set of my F8x brakes from my previous M4 Comp, so it's a question of rear brackets for me. Let me know please!

Oh man, I found the seller over in Europe and it is the same price! Here is the eBay link!

https://www.ebay.com/itm/E46-M3-F80-Brembo-Conversion-Brackets/184458311446

[Johnvu]

Wow, the brackets are made from 7075-T6? That's like overkill lol, unless someone's done proper FEA and made the decision that yes, I want to use an aluminium grade that is nearly 2x the yield strength and cost as 6061-T6.

If corrosion is going to be an issue you could anodize them. There are DIY kits you could buy

Yeah, I definitely agree here. These are way overkill and anodizing them would definitely be the best route. However, I called around and most of the places wouldn't do it for less than $100 and that wasn't worth it for me. Instead I just sealed them with the stainless corrosion inhibitor, which should be more than enough in the Texas weather.

[timmo]

Wow, the brackets are made from 7075-T6? That's like overkill lol, unless someone's done proper FEA and made the decision that yes, I want to use an aluminium grade that is nearly 2x the yield strength and cost as 6061-T6.

If corrosion is going to be an issue you could anodize them. There are DIY kits you could buy

[WestBankM4]

I'm not registered on M3Cutters but I will if I have to, before I do, has anyone gotten ahold of OP there and is he still selling the rear brackets? If you have an email address even better.

I have a spare set of my F8x brakes from my previous M4 Comp, so it's a question of rear brackets for me. Let me know please!

[Johnvu]

I just read thru the m3cutters thread and they mentioned the brackets are made of 7075-t6 untreated aluminum which degraded over time. Keep us updated on how yours is holding up?

I haven't checked on the rears in awhile but in step 0.2, I sprayed the exposed aluminum with a corrosion inhibitor to ensure they don't degrade over time. My car is also always stored in the garage and rarely sees rain, so it may not be the best candidate for corrosion results LOL.

[enjoy_m3]

I just read thru the m3cutters thread and they mentioned the brackets are made of 7075-t6 untreated aluminum which degraded over time. Keep us updated on how yours is holding up?

[Cglhut]

That much for an aluminum bracket eh, oh well perhaps its early production or something thats why its expensive.

I have a set of M2/M3/M4 brakes with only 2,000 miles on them (already had the calipers machined as well) and a set of brackets I may be willing to sell, PM me if you’re interested.

[Johnvu]

That much for an aluminum bracket eh, oh well perhaps its early production or something thats why its expensive.

I honestly think they are charging that much just because they can lol.

Here is the link to the guy on the M3Cutters forum:

https://forums.m3cutters.co.uk/threads/f80-brakes-on-e46.198617/page-4

His name is TomCress and as of April he had quite a few sets available for ~$155 + Shipping & PP fees. DM him and see if he has any left!

[mikeetastic]

Hmmm The ones I bought on eBay are no longer available. There is another set on there (CLICK HERE) but for almost double the price at $300 + $50 shipping . Check the M3Cutter forums and see if the guy is still selling them; shipping will be more expensive, but overall price should be less than that user on eBay. Good luck!

That much for an aluminum bracket eh, oh well perhaps its early production or something thats why its expensive.

[Johnvu]

Anyone know where i can get the rear caliper adaptors? Thanks.

Hmmm The ones I bought on eBay are no longer available. There is another set on there (CLICK HERE) but for almost double the price at $300 + $50 shipping . Check the M3Cutter forums and see if the guy is still selling them; shipping will be more expensive, but overall price should be less than that user on eBay. Good luck!

[mikeetastic]

Anyone know where i can get the rear caliper adaptors? Thanks.

[r4dr]

are there any markings on calipers or as long as they blue like the first post and just avoid the m2 competition?

thanks btw.

There's at least one other blue one-piece caliper that looks similar: https://www.realoem.com/bmw/enUS/partxref?q=34116799465

This came off of other cars like the M235i, I want to say they mate with different brackets for different sized rotors? But I'm not 100% on the difference. So blue alone isn't correct.

If they're blue and came off of one of the cars that you listed first (and/or part number matches) then you're good.

[mikeetastic]

All the M cars on that list will have them, but the non-M cars would have to have been optioned to have the same brakes as the M cars. M2 Competition have different brakes -- they came after the M2 LCI cars.

are there any markings on calipers or as long as they blue like the first post and just avoid the m2 competition?

thanks btw.

[r4dr]

So if i need to source the set, what donor car and year im looking for? I check realoem and partnumber and found these cars with the same caliper/rotors, is the list correct?

thanks all, really not familiar with newer cars and since ill be needing pads and rotors soon on my zcp perhaps add more money and upgrade to this setup.

All the M cars on that list will have them, but the non-M cars would have to have been optioned to have the same brakes as the M cars. M2 Competition have different brakes -- they came after the M2 LCI cars.