Brakes upgrade on UFO,porsche cayene rear

[Majorcina]

I have found rear calipers from porsche cayene(which i plan to put on front),i have found this numbers on it:
207673031 and
3D1232
The fronts calipers of this car was 18 zr
So my question is,is this any big improvment on my stock ufo's,what kind of disc i need,also what kinda of work i need to make them fit?
I sopose someone run similar set up,but i didnt have luck finding such threat
Couple of photos

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t34.0-12/10389473_10202693125767910_5896132677835024792_n.jpg?oh=903bcdd4dc11c580c9964ab0a807e6ef&oe=54EB4E9D&__gda__=1424650354_615f7ec0858c9da566eb935fb98190c6

https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xpf1/v/t35.0-12/1799120_10202693120447777_23242641814342941_o.jpg?oh=b5cef377fc491075c243bc26893af536&oe=54EBAF74&__gda__=1424656971_78f0163ce0809ae52e64a531a5fad291

[junkeravant]

They will not make much of difference if any....

The pistons are too small. Sell them & get Boxster or 911 FRONT brake calipers. They have the bigger pistons and you will feel the difference. All sorts of tuners sell the mounting brackets for the Calipers.

[Thuppu]

Yes, too small pistons. No, keep them, but put them in the rear and 18z in front.

[Majorcina]

18zr are to expensive for me,this one was cheap so i toth it will work out

[popdemonic]

Marko,
The rear cayenne calipers has an identical pistons size(28/30mm) as you've seen on any rear brembo calipers ie, rear boxster,AMG,Cadillac...
The major problem is
1. the sliding face(brake pad cross sectional) is way too narrow.
2.the maximum thickness of the disc is 28mm
If i were you,i'd rather keep this calipers for the rear setup.I also have this pair of calipers in my storage too.I believe this calipers give you
some improvement over UFO's but if the cost of fabricated the bracket is way expensive there.I'd save another bucks and do it once on bigger
calipers Marko(Front 6 pistons Cayenne's is the best bang for the buck especially if you can sort the HP2 struts over there).my 0.02.

[Majorcina]

Hey Pop,
I didnt take the calipers,i had them offered but i wanted to talk with you guys since u have much more experience with this stuff
18zr cost 500e(thats which i found) and thats only the calipers,so thats kinda to much for my budged. Anything else which can be improvment in braking(above hp2 brakes) and which dont cost a fortune for calipers only
I am not happy at all with my UFO's,and also planing to improve my rear braked with biger disc and adapter from Thuppu

[popdemonic]

Hey Marko,
I did agree with all comments.i don't think it's worth to put rear calipers on the front.
500Euros for the front calipers is sound ok but don't forget you need to add some more
euros for brackets and discs too.

[Majorcina]

This guy also have 18lz for 450e so not sure what to do since i need new discs and pads.
I saw on here how to make ufo to hp2 and i was wondering did this 18lz bolt straith on the hp2 holes?

[PRY4SNO]

Find some 17z or Boxster or BoxsterS/911 brakes for cheaper than the 18z. They have more area on the pistons = more braking force, and lighter rotors which is better for acceleration and braking.

[Thuppu]

The 18z's could be close to plug and play on the UFO strut if used the merc disc(345mm..?) For use with A8 360mm discs I can supply adapters. 17z calipers would need smaller discs to fit PnP on the ufo strut(~330mm?).

Not always bigger pistons is good. You get more pedal travel the bigger the caliper pistons are. A bigger disc also adds a lot of more force on the brakes. 18z with 350 discs is enough to stop a 2500kg Touareg/Cayenne, so it's more than enough on a 1800kg car.

Good thing with the 17z calipers are that they can be cheaper in some parts of the world. You can fit a smaller wheel on them(if used a small disc).