We have developed a DIY dual caliper kit for the people who don't mind doing the hard work themselves.
Our DIY weld on kit was all engineered in SolidWorks around a 3d scan of a Miata rear knuckle. this kit works for all Miata's from 1990-2005.
we included the following in the kit described below.
2 weld on dual caliper brackets
1 bolt on fixture plate to line up the brackets easily and guarantee a perfect fit.
4 ft of Aerospace TIG filler rod that had a higher nickle content that you wont find at any local weld supply. (we strongly recommend you have these welded by an experienced TIG welder with a 200AMP welder)
fixture bolt kit, this is critical as this hardware helps to self align to the knuckle and self align to the tab.
detailed instructions on how to align the fixture and weld the tabs onto the knuckle, along with tips on how to prep your knuckle and what amperage to weld the knuckles at using supplied filler rod.
Q: what calipers do i need for the extra pair in the rear?
A: we reccomend using the same caliper as what your current caliper already is in the rear.
for example: 1.8 sport brake cars will run 1.8 sport caliper, wilwood bbk in the rear will run another willwood. A 1.8 car trying to run a 1.6 rear caliper wont work!
Q: my brakes wont bleed properly cant figure out why?
A: make sure your brake bleeder screw is facing up, if its facing down you need to swap the calipers from left to right. Or your hydro handbrake might need to be help up higher while bleeding the lines.
Q: my caliper isn't sitting center on the rotor.
A: make sure you are matching the correct rotor with the correct caliper, or make sure you welded the tabs on correctly, you can check by bolting the fixture back onto the knuckle and see if their is any offset between the two sides.