Welcome to Flyin' Miata!

Flyin' Miata butterfly brace (NA)

Viewed from the front of the car
Flyin' Miata butterfly brace (NA)

Regular Price: $689.00

Special Price $548.00

The ultimate in aftermarket chassis stiffness.

Made in the USA

Exclusive to Flyin' Miata

Availability: In stock



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.

Additional Information

Additional Information

Part number 13-69920 1990-97
TÜV approval available No
Fits: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
Manufacturer Paco Motorsports
Flyin' Miata exclusive Yes
Fits Exocet? No
Proposition 65 Warning: Cancer and reproductive harm
California emissions No

Customer Reviews 12 item(s)

your mom will know
my 95 has been reborn. I was genuinely surprised with how much rigidity was gained from this brace. I had previously put strut bars and a hard dog roll bar in to little effect. Once this was installed even my 63 yr old mother could tell the difference in ride quality. If you don't have a lift available I would hand this job off to someone who does. Pretty simple drill job and the end result is well worth the money. No more weird chassis squeaks or twists, my car only had 73k when I put this on but now it feels almost brand new.
Review by Buffering... / (Posted on 6/27/2018)
Best Value Upgrade
Installed on a 1990 with 140k on the odometer. Simply put, it is the best money I have EVER spent on my car. I wish I had done it sooner.
Review by Stephen / (Posted on 4/26/2018)
A+ product. Thank you Flyin' Miata for engineering amazing parts for these cars
Installed on a '93 with 200k miles on Xidas. Had the frame rails about a year before springing for butterfly section. Frame rails added rigidity front and back but the butterfly brace really mitigates the side to side shaking that would happen on large bumps or railroad tracks. Really transforms the car from a limp noodle to new-ish car. One of the best mods available and a must have for higher mileage cars.

A surprising side-affect is improved steering feel on power steering deleted cars. Even with a 330mm wheel steering is much lighter and loaded with feedback

It is difficult to clear the stock downpipe on a 1.6. Had to hack away at the shielding with tin snips
Review by M3guy87 / (Posted on 2/20/2018)
Great body stiffner
Installed this about two weeks ago and i love it. My coilovers are done for so they aren't as stiff as they were in the beginning and are super loose, therefore creating a lot of body roll when i drive the canyons. This chasis brace took more than half of the body roll away, it was quite suprising and this is after upgrading strut bar, sway bar and suspension (even though it was pretty shot). I would recommend this to anyone who wants to stiffen up their car and reduce body roll, worked like a charm for me.
Review by David / (Posted on 7/12/2017)
Might be worth it eventually
I have a 1995 with 60k miles and just put on the butterfly and frame rails at the same time. I'm not sure if my car had been babied previously and retains some rigidity from the factory but I did not experience the night and day difference that everyone else did. It helped a little with the shuddering over large bumps, but I'm not sure it justifies the price/effort. In a way it's good that I got both the rails AND the butterfly, since I'd be left wondering if I only got the rails.

Please note that the reviewer who took 2 and a half hours to finish the job did it with the help of a lift AND A TECHNICIAN. This is not an easy job, especially if you're by yourself on your back. Allow for a day's work.

Advice: get a lift and a technician. No seriously, the rails weren't so bad, just be prepared to manhandle the brake/fuel lines more than you think you should. When it comes time to tighten the center section, use a 6 inch extension with a universal joint attachment. I had to remove my catalytic converter to get enough room for the driver side front corner bolt.

Bottom line: maybe it will pay dividends as the car ages and loses its inherent rigidity, but don't expect miracles if you have a relatively low mileage car.
Review by Dao / (Posted on 7/5/2017)
A good purchase
Just installed the brace on my 94. It might have been helpful if Flyin Miata mentioned what ratchit to use when tightening up the 4 bolts in the middle brace. They even admitted there would be bad words when trying to tighten them up. Over all tightend up suspension and allowed the shocks to take the bumps instead of the body. But I bought the Vmaxx extreme coilovers and sway bar combo so the ride should be 100% I think if Flyin Miata opened the rectangle opening by 1/4 in. you could tighten those 4 bolts with no swearing. It would be a simple fix. You could get a box end wrench ratchet in there and be done quick.
Review by cyouatsema / (Posted on 4/14/2017)
I finally had the Butterfly Brace installed. I had put the frame rail reinforcements in previously but should have done both at the same time. The car is completely transformed. I have the FM Stage 1 suspension so without the bracing it made the car shake worse. I really can't believe how solid the car is now. I agree with the post above, that this should be one of the first things you do for your Miata.
Review by Drmoto / (Posted on 12/20/2016)
Best chassis upgrade for the daily driver
Installation is actually really easy, FM's instructions are very detailed and give good tips. The great thing about this upgrade is that it stiffens the chassis while maintaining stock appearance and convenience.

It will not stiffen your car as much as door bars combined with a roll bar, but obviously for daily driving you don't want that as the Miata'a cabin is small enough already. This is the best practical bolt-on chassis upgrade!
Review by RyGuy / (Posted on 11/29/2016)
If you are a true driver this is a must.
The difference right after I installed this wasn't completely noticeable at first, like new shocks or sways. When started to build some speed and push the car a little I really noticed the difference. Much more responsive steering and turn in. It's like my suspension wasn't really doing its job before the brace because of so much chassis flex. I had to back off some of my adjustments on the rear end to keep the car tame for commuting. The added bennefit of solid jack locations all the way down the car is just a bonus. If you are planning a suspension upgrade this should be on your short list.
Review by Scott / (Posted on 4/19/2016)
Excellent modification
TRANSFORMED MY 61k mile 1994 miata!

Don't even question the price. It's the best $400 you can spend on transforming your car. It's rock solid. The car went from a quivering shuddering mint condition miata to a strong solid pumped up version of its former self...

I noticed it the first few feet. There is no question the vehicle has the structural rigidity it always deserved. The suspension now has the job of soaking up the potholes or uneven pavement...not the cowl...not the body and not the interior pieces rubbing together...

All that nonsense is gone with this modification.

The feels really solid and much more stable. Mid corner bumps no longer upset the car or driver confidence....

It's a whole new world...

2 and a half hour install in the lift. Lots of fun. Great instructions.....

We disconnected the wiring from the ecu and placed a small piece of wood under the ecu just because I'm extra careful ...didn't need it. The rails went on easy pizzy....the butterfly we put together and used a jack to suspend in place while we set the holes...

The bolts went in easy....the fuel lines and brake line was no problem to move a little and reset by floating out the 90 degree clamp..

I'm far from a mechanic and I had a technician do the work with me...

Just a fun day and the results are outstanding....

I was thinking of doing the shocks but I don't even have to...all the shuddering and quivering the car did is gone...

Now it's chassis rigidity rivals the best sports cars....this is what my miata needed and I am glad I did this butterfly brace from flyin miata.

I highly recommend this easy modification that is truly transformative for the miata.

Glad I did this mod.

Hope my insight helps others

Review by JB / (Posted on 7/14/2015)
Excellent, must buy.
Excellent item. Probably the best money I've spent on my Eunos. If I knew how much it effected the handling and feel when I first got the car this would have been my first upgrade.
Review by cookyy2k / (Posted on 7/14/2015)
This almost should be mandatory for any NA
I can't rave enough about how awesome the butterfly brace is. It completely changes the character of the car for the better, both at low speed and highway cruising. Bridge expansion joints and road imperfections get soaked up with more confidence, and the car feels light years more solid.

Not only that, but it makes working under the car easier, as the frame rails give you more options for putting the car up on jack stands. I'm not sure if this is just coincidence, but my jack stands fit absolutely perfectly onto the FM frame rails. It's like they were made for each other!

Really, this should be one of the first things you get for your Miata.

If I had to find something to complain about, the center section can be awfully frustrating to install and get fitted. You will notice how crappy your old exhaust hangars are looking, too.
Review by VividredMiata / (Posted on 3/20/2015)
Click here for instructions for this part.