Originally Posted by The HACK
If you mean take the existing front OEM caliper and use it in the rear, the answer is a simple NO. First you would have to custom fabricate a bracket to fit the much larger caliper to the rear. Second, that rear caliper now will have significantly increased in size of piston and therefore completely f**k up your front/rear balance AND totally screw up your master cylinder to slave size ratio.
It won't work. The only reason(s) why most front only kit works, is that the overall surface area of the multiple pistons are no larger than the factory single piston size, so the brake proportioning remains the same while brake torque, heat capacity and dissipation has increased thus improving overall efficiency.
Do you know what the single piston size is in the front of the 335i?
The stoptech 335i kit is 4x30mm, 2x36mm... unless the stock piston is ~70mm, then the stoptech caliper would have more piston area. If the front piston is 60mm, then stoptech has considerably more...