Customer Reviews
tldr; This is arguably the best upgrade I've done for my '93. I'd argue 30% improvement in stiffness.
My Miata life started with an '02 NB with delrin door bushings and Megan EZ-II's, but no other suspension changes or stiffening to speak of. Of my own accord, I would have ballparked the door bushings alone (in both the NB, and NA) as a 3-5% improvement in stiffness. If you check the FM Door Bushing page, you will see that they have measured a "3% improvement in torsional rigidity on a 1990" and I think that is spot on, based on my experience with both my NB and now my NA.
One of my hesitations on pulling the trigger with the Frame Rails + Butterfly Brace, was the lack of any indication of a stiffness improvement expressed in a similar percentage. After calibrating my personal "StiffyDyno™", I would personally ballpark the improvement (for my specific NA with a mangled driver side frame rail) at around 30% improvement. It is seriously shocking how transformative this can be for your car.
I used to grit my teeth over potholes, but that is a thing of the past. The added stiffness truly does allow my suspension to actually do it's job, rather than just shove the body of the car around.
Just a few notes:
1) I used QuickJacks to get under the car, and did the entire install solo. It is possible to do, but if you can have a helper, get them. It's a lot of up and down, otherwise.
2) Do yourself a huge favor and grab some titanium drill bits from Home Depot etc. - probably 10x better/easier than forcing a wood bit through your floor.
3) I did snap like 2 nuts off the bolts while tightening. Not sure why, I was totally within the torque spec. A couple extra pieces of hardware would be appreciated (like 2-3) to avoid having to stop and run to the hardware store. Or overkill it and just send grade 10.9!
Thanks for your review! We're glad to hear that our Complete Butterfly Brace made such a positive impact on your Miata! 😀 Sorry to hear about the snapped hardware, though! That's pretty unusual. If this kind of thing happens in the future, please reach out to us directly so we can help get you sorted with replacement hardware, etc.
Was paranoid about drilling into the car like others. Mine being a 94, take extra care when drilling by the ecu. This is a good time to lay down sound deadener/carpet padding. The video seriously helps with install and I love that FM takes the time to make tutorials. These were the last (and most anticipated) bracing mod I did to my car so perhaps the results weren't as dramatic as I was hoping for. The car also has Paco strong arms and FM STB. Yes the car feels more solid, it takes bumps better. Doesn't completely eliminate NVH but helps make a 30+ year old convertible stiffer. You can feel the added weight, seems to give the car a more substantial base to let the suspension do its job better but a vintage car will still flex and rattle . Also, even though my motor mounts were new and exhaust hangers in okay shape, I did have to dimple the stock down pipe slightly for clearance. ymmv. Having a lift and someone to help torque the hardware down would save so much time.
I've been upgrading my NA Miata exclusively with Flyin' Miata (FM) components since 2001, starting with the FM II Turbo Kit. Over the years, I've made more than 30 major upgrades to my car using FM products. After the FM II Turbo Kit, this latest upgrade is, without a doubt, the most transformative. In my 20+ years of ownership, my Miata now feels like a different / brand-new car. If you're considering this upgrade, don't hesitate—it's worth every penny. I only wish I had done it sooner.
I installed this in my 1996 miata and it made the car feel so much more rigid. Installation was simple and straight forward. As long as you follow the directions on the frame rail installation the butterfly braces fit spot on. It was an easy install for me, took about an hour and a half, with a good chunk of that time markings and drilling holes. I recommend getting a good drill bit it makes the job a lot easier. Hardware worked excellent with none breaking or stripping before reaching the recommend torque specs the directions provided.
The kit installed good. To be sure the railes lined up, and the front butterfly brace lined up, we installed it before drilling the holes in the chassis (adjusted the rails during this step). We drilled the holes we could get to (all but one each side), and anchored it snug. Removed the butterfly, and drilled the other two holes, and anchored. The only issue is the intermediate pipe rests firmly on the front section of the front butterfly. It is a 1999 car, and only has 2200 miles on it, it is prestine! I have to figure out a way to get that intermediate pipe up higher...
It's surprising to have exhaust interference on an NB, but you could try stiffer exhaust hangers to keep it from sagging too much. You could also remove the stock heat shielding around the pipe at the interference.