# What size are these? help. Audi brake conversion



## VDub2625 (Jan 4, 2003)

I know it's hard to tell, but bear with me. Found these in the yard:









Car was a B5 A4. Obviously, they've been upgraded, and all my research tells me they're most likely 312mm, since that is the more common size available (I compared the rotors to 11.3s, and they were easily about an inch bigger). They are single piston. Also, from what I've found out from ETKA and looking around, the carriers should fit on my Mk3 5 lug wheel bearing housings (the bolt holes are definitely the same distance and they will bolt on). 

I forgot to measure the rotors exactly, but I am 98% convinced they're 312mm, in which case all I need are Audi TT/GLI 1.8T rotors to fit them onto my Mk3 5 lug hubs, correct?

Anything else I should be aware of for this conversion? I have a set of Montreal IIs to go on the car with them (16x6.5), and those should fit ok? Thanks!


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## Eric D (Feb 16, 1999)

Look for the number 451 stamped on the carrier. That is for the 12.3" brakes.
If it's stamped 301 its for 11.3" carriers.


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## VDub2625 (Jan 4, 2003)

Eric D said:


> Look for the number 451 stamped on the carrier. That is for the 12.3" brakes.
> If it's stamped 301 its for 11.3" carriers.


Is there a specific place? I looked on all visible areas and didn't see any markings. I haven't removed the caliper from the carrier though. 

I did compare the rotors on the Audi to a mk4 VR6 (11.3"), and they were clearly an inch or so larger, so I know they're at least 12". What I'm unsure of is exactly what size, since there's 312, 321, 320, blah blah blah for Audi and VW from about 02-today that they could potentially be. But like I said they're likely 312 since that sends most common. 

I will snap a picture of the pad when I get a chance soon. That seems to vary on the later 12" brakes, along with the caliper. They look the same as 11.3 calipers I think, thigh, which are shared on the 312.

Sent from my LG-LS970 using Tapatalk


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## Eric D (Feb 16, 1999)

On the ends.


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## VDub2625 (Jan 4, 2003)

Thank you, they fit fine with the GLI 12.3" rotors 

Another question... what splash shields (if any) do I use with these? The stock 11" ones interfere, and the spindle holds them VERY close to the rotor. Maybe with the flow-through vent design, there is no splash shield? Help please! 

EDIT: I have found these:
http://www.ecstuning.com/ES454494/
8N0615311A
Jetta GLI, Audi TT

http://www.ecstuning.com/ES7647/
1J0615311B
GTI 20th anniversary with 312mm brakes

Same cars (Jetta/GTI), same brakes, different look and shape?


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