Okay i was cleaning all my rotors and came across this set...Not sure of the year of the rotor but are 12a...What is up with the design of the rotor? Why are they textured the way they are...Both rotors are designed this way

 

i dont recall seeing grooves like that on either of my set?

 

Those look, to me, like something that should not have passed quality control. They were poorly machined.

 

wish you could see them in person...the rotors are really lite have glare to them and the grooves are equal all the way through...any ideas

 

They are milled differently, perhaps, older?

 

those rotors, i almost bet are just a hair bigger then the others you have just by .010-.015 of a inch. Those were machined using a roughing endmill but never finished. I see those lines everyday working in a machine shop.

This was not a design it was most likely a screw up.

 

the faces on my S4 13B are like that. I've heard some came that way, some don't.

 

really, thats weird, are they worth keeping any uppers to keeping them and running them? Or just to keep them and say hey i got a fucked up pair of rotors from the assembly line sorta say?

 

MORE COMPRESSION!

Jk.

I would say some flaw in the machining/casting process.

Are those pictures from the future or something?

 

I've seen those on a customers FD. - Potential hotspots ?

Like Rob mentioned, they are from the rough milling stage.

 

You will find some of the same machining marks on S4 and S5 rotors, usually in the 'bathtub' area, not usually around the entire surface area. I don't believe the are bad, they may have been balanced . The grooves do make for a good spot for carbon to accumulate.

 

yeah there was **** load of carbon build up on them through out the whole rotor...I guess i thought i had something special...lol

 

ive never seen that on a 12a rotor, but i do on the fd rotors. its like they have 2 machines, one that spits out "normal" looking ones, and one that spits out rotors that look like that.

 

i guess there one of kind rotors if anything that were jsut fucked up from the factory...These rotors ran really well on carbon's...I couldn't complain