I'm still researching, so please bear with me and make corrections.
The mazdaspeed 3 front rotors and calipers will "bolt on" with the correct bracket for the caliper and different bolts to mount it to the knuckle. This leads me to believe the knuckle mounts are identical across the board for the 5, 3, and ms3. The issue I see is the clearance between the caliper and the stock 5 wheels. Phunky Buddha used a 3mm spacer and MX5 wheels and made the clearance work.
Here's what I've found. http://www.therpmstore.com/store/p/...Front-Brake-Caliper-Kit-for-Mazdaspeed-3.html
The caliper is 1.67" from the rotor face to the outside of the caliper and the mazdaspeed3 users say the caliper is "smaller" than the oem calipers and gave them more clearance between the caliper and wheel.
Would it be safe to say that the "thinner" wilwood caliper clamping down on a ms3 rotor would fit behind the oem 5 wheels or should I keep researching?
Thanks for looking!
The mazdaspeed 3 front rotors and calipers will "bolt on" with the correct bracket for the caliper and different bolts to mount it to the knuckle. This leads me to believe the knuckle mounts are identical across the board for the 5, 3, and ms3. The issue I see is the clearance between the caliper and the stock 5 wheels. Phunky Buddha used a 3mm spacer and MX5 wheels and made the clearance work.
Here's what I've found. http://www.therpmstore.com/store/p/...Front-Brake-Caliper-Kit-for-Mazdaspeed-3.html
The caliper is 1.67" from the rotor face to the outside of the caliper and the mazdaspeed3 users say the caliper is "smaller" than the oem calipers and gave them more clearance between the caliper and wheel.

Would it be safe to say that the "thinner" wilwood caliper clamping down on a ms3 rotor would fit behind the oem 5 wheels or should I keep researching?
Thanks for looking!