Hello everyone i know everyone on here likes to run big brakes so i have a question, im looking to install rear boxster s brembos onto my car, i have done some research and i have a question for anyone here who has done the conversion.

Stock boxster s rear rotors are 299mm x 24mm, the largest rear rotor i can get for my car is 299mm x 20mm. I looked up the specs and they say 22mm is the rear rotor replacement thickness.

Since i can only get a 20mm wide disc with boxster s pads can the brembo pistons start to leak or exit the caliper if i run this set up? Or is there enough travel in the pistons to keep everything together?

Thanks everyone!

The issue here is that we don't know how much piston you have to work with. So we couldn't really tell you if it will leak or not.

Your guess is as good as ours. Rotor replacement thickness has to do with structural integrity of the rotor itself and it's ability to dissipate heat, not the pistons.
Also, check the specs of your front rotors and whether or not it will fit on the rears.

Also, consider how much the pistons would have to travel after the pads AND the rotor are worn all the way down.

Assuming the following:

New pads = 12mm
Brembo rotor (new) = 24mm
Brembo rotor (dead)= 22mm
Stock rotor (new) = 20mm
Stock rotor (dead) = 18mm <-(Just assuming here, -2mm)

You will be extending the brembo pistons 2mm on each side (fixed) or 4mm on the single piston, when you run new stock rotor/pads with the brembos.

By the time you finish the pads and the rotors, you're extending the piston 12mm from our 2mm baseline. (14mm extension)
If the upgrade calipers are fixed, then the pistons on each side will extend 12mm. (14mm extension)
However, if the upgrade calipers are floating, that single piston has to extend 24mm to make up for the pad wear and the rotor wear. (26mm extension)

This post was edited by SlyGoSu on Dec 30 2014 11:25pm

The front will not fit, the ebrake is integrated to the inside hub of the rotor so the largest rotor i can find that will keep the e brake working is 299x20. Its a 4 piston brembo so both sides would be moving inwards at the same pace. I was also thinking that about rotor integrity but in that case 2mm on off on each side would be equal to a slightly worn out pad. so if i dont take the pad all the way to bare metal it should have no problem..




this is the spec of the brembo pad

This post was edited by Avenger987 on Dec 30 2014 11:28pm

Was worth asking, lol.

Well the 4mm difference in rotor thickness is hypothetically equal to 2mm on each pad, so yes, hypothetically, it should work.

As a side note, I doubt that they'd make the end of piston travel before leaking so close to full pad/rotor wear, but don't run the pads to bare metal, just in case

This post was edited by SlyGoSu on Dec 30 2014 11:44pm

Yeah that was what my common sense said but just needed to hear another opinion, would a brake pad spacer exist possibly? Thanks bro!

This post was edited by Avenger987 on Dec 30 2014 11:44pm

Not that I know of. You can add extra pad shims, I'd advise against it though. Stick to not running pads to metal and you'll be fine. No need for fancy things

No probs!

Yeah screw it, i believe! lol my front ones will be installed soon waiting on my brackets

Call them, they have people that answer these questions

picked them up today did some math, if i wore the pads down to bare metal 25%-30% of the piston is still inside the caliper.