Feeler: Girodisc 2-piece floating rotors for E46 M3

[Obioban]

Next trick is to get FCP to sell them!

[tlow98]

I'd love a post on how brake rotors are made

i second time this!

[r4dr]

Are the dimensions still 345x28?

Yup, stock CSL/ZCP rotor size.

I'd love a post on how brake rotors are made

Let me see what I can put together. It's an interesting process and it's very different from mass-market one-piece cast rotors or the co-cast factory discs.

[r4dr]

Teaser pic, Bimmerworld listing coming soon.

[r4dr]

Looks sick. Any idea the weight difference between these and stock or ZCP rotors?

These came in at 17.5 lbs per assembly (hat + ring with hardware). I have in my notes that the ZCP co-cast rotor weighed 19 lbs when we had a new one here. Can't recall if it was a genuine or Zimmermann unit, I can double check if we documented that.

[Tbonem3]

Ofc I have FCP CSL rotors

Would absolutely rock these otherwise.

[r4dr]

Ofc I have FCP CSL rotors

Would absolutely rock these otherwise.

I can send you the high res pics to look at and tempt yourself.



"Unsprung weight... rotating mass..."

[Tbonem3]

That's my "love language "

[pawa_k2001]

Still interested in a rear rotor if you guys make one.

[r4dr]

Bimmerworld order link: https://www.bimmerworld.com/GiroDisc...-345x28mm.html

They bought up the first production run, so I would recommend placing your order there. Let me know if anyone has any questions.

Still interested in a rear rotor if you guys make one.

Me too. Stay tuned.

[Cronenberged]

r4dr bring us an update beginning of next year please.

[r4dr]

We made some progress today. Thanks to rapid prototyping via 3D printing, I test fit a proof of concept cross-section to see how much room there would be with a Porsche caliper. Plenty of clearance. Note that this is with the D738 pad shape (much more common Cayman rear) versus the D737 shape (986 front) which people run to sweep the full E46 rear rotor.

For the fellas who want to keep the stock rear caliper, I double checked with PFC's current stock on their 7855 shape. This is the custom shorter pad they developed to run with their own 2-piece rear rotor. They have plenty available in race (including PFC11) and street Z-rated compounds.

With this setup, we should be able to run off the shelf pad shapes while retaining the factory e-brake.

[pawa_k2001]

Nice. Definitely interested since I am looking to replace rear rotors very soon. Will be looking for weight since I want these as a weight savings over OEM.

[r4dr]

Finally had the chance to install my front Megane RS kit with the rotors and they fit like a glove. I'm still impressed by the bang for buck with the Freakyparts kit. Rears are next on my list!

[maupineda]

Finally had the chance to install my front Megane RS kit with the rotors and they fit like a glove. I'm still impressed by the bang for buck with the Freakyparts kit. Rears are next on my list!

NIce, can you share your impressions when compared to stock? I have 6-Pot E82 calipers and they are nice, but if I am honest they dont have as much bite. the calculator shows they have less clamping than OE, and it shows. I think these with the larger pots dont degrade clamping force. do you know the piston size?