I bought a used Flyin’ Miata front sway bar for the 00 SE a while back and installed it on the car. My son got a Racing Beat sway bar for his car, but also bought some sway bar mount supports. I wanted to add the supports but could not see spending $90 for some bolts, nuts and two pieces of aluminum. So this is what I came up with.
First I removed one of the sway bar mount bolts. It is an 8mm x 1.25. I then measured the distance from the frame to where the bolt head sits when installed. It is just over 60mm. I then ordered some stainless steel nuts and bolts and some spacers from AllensFasteners.com. I ordered extra of each since this was an experiment to see what would work.
I ended up using the following:
(4) 8mm x 60mm x 1.25 stainless steel bolts
(8) 8mm x 1.25 stainless steel serrated flange nuts
(4) 8mm x 1.25 stainless steel nuts
(2) 5/16″ x 1-1/4″ chrome spacers
I cut the 1-1/4″ spacers in half, so I could have ordered four 5/8″ spacers instead. I ordered the 5/16″ spacers since the hole is perfect size for the 8mm bolt.
This is how I used the parts.
Notice I used a flange nut against the head of the bolt. This was necessary since the bolts did not have a flange on them. I used the standard nuts as a lock nut to hold the spacer firmly in place against the frame.
I believe the spacers contacting the frame will be adequate support for the extra pressure exerted by the stiffer sway bar. They work the same way as the $90 kit that my son got.
I will keep an eye on them to be sure they work as planned.