Pricing note: Our March 2019 catalog accidentally had the frame rail and butterfly prices swapped. We do have the butterfly on sale, but the price on the website is the correct one and not the one in the printed magazine. We apologize for any confusion. The good news is that the frame rails are considerably less expensive than shown in the catalog!
The Flyin' Miata butterfly brace does spectacular things to a Miata. We installed one of these on a friend's car without telling her. She noticed the stiffness by the time she'd backed out of her driveway. In fact, her mother noticed from the passenger's seat. The ride is improved because the entire car is now a solid unit. Handling is improved because the suspension has a more solid platform to work from. You cannot have a chassis that is too rigid.
How does it work? It ties both sides of the car together and "closes the box" for the transmission tunnel. Mazda knows it works, they added something similar themselves in 2001. However, Mazda did not reinforce the frame rails like we did. Designed by FM and exclusive to us.
The brace is made of laser-cut stainless steel that is folded and stiffened with ribs on the back side. The center section is adjustable for height to clear almost any exhaust. We have tried to build in as much adjustment as possible, but due to the plethora of aftermarket exhaust configurations we cannot guarantee perfect clearance with every combination. We haven't found one yet that doesn't work. In most cases, ground clearance is not affected. The fuel lines and rear brake lines are tucked away and protected from impact. If the exhaust or transmission needs to be removed, the center section can be unbolted for full access. 28 holes need to be drilled for installation. Our frame rails are included as part of the butterfly brace.
Developed and engineered by Flyin' Miata. We know there are cut-rate knockoffs out there, but they're made of much thinner, weaker material so they won't be very effective. We use a combination of 14ga and 12 ga 201L stainless steel for maximum strength and longevity.
Fits all 1990-97 Miatas except 1990-93 models with the stock header and catalytic converter. 1990-93 models with an aftermarket header or turbo downpipe and an aftermarket cat are fine.
Weighs 32 lbs, all below the CG of the car and well centered for the minimum effect on handling.
Here's what Grassroots Motorsports had to say about it.
Our Mariner Blue 1990 Miata—the very car that graced the cover of the June issue— has had a long life. It’s now pushing over 200,000 miles and has shown no signs of giving up the ghost. While new Miatas never really felt that stiff in the chassis-rigidity department, our rat has come to feel pretty flimsy over the years.
We recently gave the car a physical boost with the installation of Flyin’ Miata’s butterfly brace system. These laser-cut pieces of stainless steel tie the front and rear subframes together to create one beautiful structure. The kit took us a little more than two hours to install, and that includes the time it took to remove the seats and carpet for the drilling of the required holes.
Now when the steering wheel is turned, the front and rear suspensions instantly respond, making the car much more predictable. In one instant, it’s like we removed a few hundred thousand miles from the odometer.
The Flyin’ Miata Butterfly Brace is an impressive piece of engineering, as it improves the Miata’s rigidity with no real downside.