Using Brembo 2-Piece Type 3 Rotor w OEM '13-'14 GT500 Caliper

[cholmes1]

I am going down a rabbit hole with the Type 3 Brembo rotors 380x32 front for my 2013 GT500 caliper swap on my 2013 Boss 302 LS and am hoping for a greater explanation of why I have been repeatedly told that Brembo Type 3 rotors cannot use custom hats and work with the OEM '13-'14 GT500 calipers?



For example, if you purchase the rotor rings separately and make custom aluminum hats, I see no reason why this would not work; that said, I am not an engineer and not nearly as skilled with brakes as many on this forum



If the OEM ’13-’14 GT500 rotor is 14.96"x1.26" or 380mmx32mm

Rotor Outside Diameter (in.): 14.96" = 380mm

Brake Rotor Bolt Pattern (in.): 5x 4.50"

Brake Rotor Bolt Pattern (mm): 5x114.30mm or 5x4.50"

Nominal Thickness (in.): 1.260" = 32mm



and the Brembo Type 3 rotor/ring is also 380mmx32mm or 14.96"x1.26"



Why would you not be able to take a custom hat CNC cut to the same/similar specifications as the OEM replacement hat sold by Baer for their 2013-2014 GT500 Eradispeed OEM rotor swap but use the bolt pattern from the Brembos (10 in ring circle as opposed to 12)? Especially given multiple Brembo race setups utilize the 380mm rotor. Even if a larger width ring was selected, like 34mm, you could adjust the pads, and it would fit.


Baer Eradispeed Hat Specifications
Wheel Bolt pattern 1: 5 x 4.50" or 114.3mm

Wheel Bolt Hole Diameter: .625"

Baer Rotor Bolt Circle: 12 x 8.500" (Cut to match Brembo Type 3)

Rotor Bolt Hole Diameter: .257" Through hole (Cut to match Brembo Type 3)

Hat Center Bore: 2.796"

Hat Depth: 0.235" (Likely a further adjustment point - but maybe not)

Hat Face Thickness: .300"

Mount Style: Fixed or Floating (Custom McClaren Hardware)

Material: 6061 T6 Aluminum



Has anyone made custom hats? I know they are more common in the kit market (Factory Five, etc.) ,but hoping someone has insights or some glaring aspect I am overlooking.



I like the Girodisc rotors, and having spoken with them yesterday, I know some very nice developments are coming this summer for all S197s (especially 2013-2014 GT500s) to enjoy. However, I still am confused why the multiple vendors I contacted stated custom hats of the Brembo Type 3 rotor could not be done with the OEM caliper.

I could understand vendors saying Type 3's are ‘not recommended for primarily street,’ a ‘waste of my time or money to make it work,' or even ‘possible but look, we sell XYZ, which is easier/better' but to say ‘it cannot be done' is confusing if the only limitation I can see for fitment is making certain the hat is perfectly aligned to the OEM '13-'14 GT500 caliper.


Any and all help/guidance is appreciated.

 

[Bad Company]

At one time Ford Racing, now Ford Performance offered a 2 piece Brembo rotor kit to replace the stock rotors for the 2013/2014 GT500. The 2 piece rotors use a traditional aluminum hat with a steel rotor ring to reduce unsprung weight as the factory 1 piece rotors weighs approximately 30lbs each. The kit reduced this by 10lbs at each wheel if I remember correctly. I bought this kit as at the time no one else was offering a aftermarket 2 piece rotor to reduce weight. At the time the only ring available was a solid ring, no drilled, slotted or grooved ring was available through Ford. My thought were to replace the ring with a Brembo slotted ring if I ever needed to in the future. I don't believe Ford will ever offer a replacement rotor or ring for this application in the future. Ford advertised this kit as a custom design that they worked with Brembo to offer. I don't know if the custom aspect was the fact it was a solid ring so that it wouldn't change the braking characteristics of the car which would then not effect the way the ABS system functioned or what. I couldn't find any information about whether any of the 380mm x 32mm rotor rings from Brembo would fit the Ford Racing/Brembo aluminum hat. What you're purposing has been done by Brembo and Ford Racing

Now the Type 3 ring is going to be aggressive on a street car with a lot of initial bite as you apply the brakes. It probably will upset the balance of braking between front and rear and it may also cause issues with the ABS system if you can't find something for the rear axle that will work in a similar manner. The Girodisc rotor you put a link to came out shortly after I bought the Ford Racing kit, I would probably go that route today. Also the cost of the Brembo rings is close to what the complete Girodics kit costs with the hats, by the time you purchase the Brembo rings and then machine a custom set of the hats you'll have considerably more money in the Brembo rotors versus the Girodisc kit

 

[cholmes1]

Thank you @Bad Company. I am familiar with the FRPP unit you described and believe some are still available through Dean Martin at Kohr. That said, you are correct that FRPP is certainly not making any new rings, so using them for actual track use would be a challenging effort knowing they cannot be replaced. I attached an image of the rotors at a PRI event if you have not already seen how they were displayed when they were released. They look great and were certainly a great factory option when they were released.

Fortunately, a racer on a separate forum (JAJ at TMO) highlighted that the challenge with the OEM to Brembo match is down to the annulus length, not the exterior dimensions. He ultimately found that Brembo does make a Type III ring that is a nice match for the OEM dimensions for the GT500 ring. It is 380x32 with a 65mm annulus to fit the '13-'14 GT500 pad size.

Brembo Rotor - Porterfield Brakes Official Site

OD 380mm, Thickness 32mm, 10 X 232mm, 48 Vanes, Left Rotor GT3R w/Annulus Front

porterfield-brakes.com

You are correct that the Girodisc options are the easiest (and they are an awesome company), plus they do have some exciting '13-'14 GT500 releases pending this Summer that will certainly be purchased. That said, seeing that Brembo has a ring that will work does warrant that I investigate further. It will certainly cost some time and money, but if/when it works, it should benefit the whole community

** Separate question - does anyone have a go-to source for caliper hardware? I am looking to replace my anti-rattle spring and the pad retention bolt and pins **

 

[tomshep]

Did I understand you to say Girodisc is going to be releasing a 2-piece rotor set for front/rear? Any pricing yet?

Tom

 

[2011 gtcs]

I hope Griodisc makes a rear set for the 13/14s. I'll be buying a set asap.

 

[cholmes1]

Did I understand you to say Girodisc is going to be releasing a 2-piece rotor set for front/rear? Any pricing yet?

Tom

I cannot speak in specifics, and have no idea regarding pricing, but yes, Girodisc is planning a matched front and rear 2-piece set for the ‘13-‘14 GT500. The slot design is being revised and the hat color may be changing as well. All pending for this Summer

 

[cholmes1]

I finally connected with US Brembo engineer Dani via George at Race Technologies to discuss a variety of Brembo rings, and the annulus and/or air gap are the deciding factors for why a Brembo 2-piece rotor ring cannot be used with the '13-'14 GT500 caliper. If one was correct, the other was way out of balance.


Girodisc really is the best player in this game for a race-spec 2-piece rotor for the '13-'14 GT500 caliper. While Baer and FullTiltBoogie offer 380x32 2-piece setups, they lack the thermal capacity to be effective in anything beyond street driving, though they are very lightweight. StopTech offers their 380x32 2-piece AeroRotor, which may be a bit more robust but still not on par with the Girodisc option.


The closest Brembo option to OEM was disc 09.A009.22 at 380x32 with a 65mm annulus, but the air gap is 20mm v OEM 12mm. Essentially, the disc is the same thickness as OEM (32mm), but the rotor wall is 8mm thinner, greatly diminishing thermal capacity.


Disappointingly, the rabbit hole I fell into came to an end without any positive results for the community. Thanks again to JAJ at TMO for his insights. My thought with this project was, "If it works, we all benefit, and if it does not, my wallet and time were the only casualties." Fortunately, my wallet was spared, and my time learning the nuances of brake rotor construction, and caliper pairing was worthwhile. I eagerly await the Girodisc releases this summer.