I drive a 2011 XJL S/C and I'm lost and could use some help.I purchased the EBC Stage 4 brake kit S4KF1323 for the front and S4KR1175 for the rear but they are all way too small. Some websites show 14' rotors and some show 14.8" or 15". The dealership was a whole lot of help. He said nooooo your have 480 MM rotors. Killin me!!
Is there an upgraded brake system that bumps the rotors from 14" to 15" on a supercharged XJ?
Thanks guys,

 

Not an XJ owner but I'm fairly sure a 2011 XJL SC would have the exact same brakes as a 2010/2011 XFR (I used to have a 2010 XFR) which are 380 mm front (not 480 mm - typo?) and 376 mm rear. Both are sometimes called 17" in parts catalogues.
Without checking I would say the EBC kits you have are for the "cooking" XJ with 355 mm front and 325 mm rear brakes, sometimes called 14.8" and 14" in parts catalogues.

 

380 mm = 15" or 14.96" rotors. I have a 2012 XJ 5/0 S/C.. If you look at the Centric catalog (or access the listings at a place like Rockauto.com) they have the dimensions listed. The 380 mm rotors use 2 piston calipers, ans I believe the smaller ones are single piston.

 

Yes, 380 mm = 14.96", but that is not what the parts listings are measuring when they talk about 17" or 14" parts.
I have been there done that many times and still haven't figured out exactly what the hell the parts listings are talking about with these brake part measurements in inches but take it from me they have absolutely nothing to do with the actual diameter of the brake rotors!
And yes, the front 380 mm brakes are 2 piston and the 355 mm brakes are single piston, I have had both and done several brake pad and rotor replacements on both.

 

Agreed you have 380mm front and 376mm rear. The easiest way to confirm you are ordering the correct parts is to call the seller and tell them the brakes you have and ask for the best corresponding part. I did this with R1 Concepts and the rotors and pads were exactly the same size as stock.

All the best.

 

Cool. Thanks for the info guys. I'm glad I'm not the oly one to have this problem. I have a call in to EBC and will see what they have to say.

All the best,

 

"The easiest way to confirm you are ordering the correct parts"..... is to measure your brake rotors.