Flyin' Miata Frame Rails

I ordered a set of these when FM had their Black Friday sale, and they just came at the end of last week (the sale was apparently more popular than expected)!

Since my wife and son were out of town, I actually had time to install them. I'm a fairly competent mechanic when it comes to simple things - I know just about enough to get myself into trouble, and sometimes enough to get out of it too - but these were even easier to install than I expected. Did it on jackstands in my driveway, and pulling my seats was probably the hardest part thanks to my particular setup. All in all, it took somewhere around 3 hours start to finish, including some persuasion of my poor car's framerails.

I've heard a lot about these over the years, but I have to say - the effect was WAY bigger than I expected. The car feels totally transformed. A lot of that probably has to do with the fact that my Miata has 230k hard miles on it, but WOW! Consider me another happy customer.

Now I have to deal with my failing alternator (crossing my fingers that I make it home from work today), but that's another story. It's a much less creaky and rattly car, and it's so much more enjoyable to drive. If you're considering a set - it's definitely worth the time and expense.

Guessing this is the butterfly brace?

Pete

pictures needed. That's awesome though. Always good when a new product makes a tangible noticeable difference. 

Pictures are not exciting - here's one from.when I finished the first side

This is actually just the rails, with no butterfly brace. I imagine that the brace has an even bigger effect, since it ties both sides together and boxes the bottom of the car.

Thanks for the kind words!

This isn't the butterfly brace, he's talking about just the frame rails. The butterfly brace adds on to those to make even more stiffer!

Frame rails:

Full butterfly (which includes the frame rails)

I'm entering year 2 of not installing the ones that came with "Nice Miata" I don't know why maybe the missing hardware (PO didn't include it) posts like this increase the motivation. 

I really liked my FM frame rails.

so hypothetical do these put one in PR or MR for rallycross?

Been considering these since the stock rails are crushed on my 99. Due wonder how it would affect autocross classing. Can't make out if it would affect from the rule book. Going STS this year.

MrChaos said:

so hypothetical do these put one in PR or MR for rallycross?

MR.  Not allowed in PR (well, SR-and-therefore-PR) unless you can conclusively prove that they are protective equipment, meaning they are required in order to keep the chassis from failing.  Since Miatas cracking in half is not a known chassis issue, I don't think it would fly.

IIRC, you are allowed to replace the hardtop's quick release latches with bolt in brackets even in Stock.

In reply to wlkelley3 :

Unfortunately I'm pretty sure these technically send you all the way to prepared. It's the kind of thing that people tend to not care much about locally, though. Ive given up on building a competitive car since I now drive this daily, so I decided that the trade-off was worth it.  Also, I'm pretty sure your 99 would be in STR, not STS

Byrneon27 said:

I'm entering year 2 of not installing the ones that came with "Nice Miata" I don't know why maybe the missing hardware (PO didn't include it) posts like this increase the motivation. 

Give Flyin’ Miata a call/email and they might be able to help point you in the right direction for replacement hardware and instructions.

Everything I’ve read says they make a very noticeable difference and are worth the relatively small amount of effort to install them.

cmcgregor said:

In reply to wlkelley3 :

Unfortunately I'm pretty sure these technically send you all the way to prepared. It's the kind of thing that people tend to not care much about locally, though. Ive given up on building a competitive car since I now drive this daily, so I decided that the trade-off was worth it.  Also, I'm pretty sure your 99 would be in STR, not STS

That's what I figured.

I've heard the thing about NB not allowed in STS. Rules do not specify a year. Rules just specify open diff which my car has. Open diff means STS, Torsen limited slip means STR or CSP. Been in CSP locally the past few years because I like R-comps. Tired of being outgunned and want to go where there is similar cars for friendly competition. The recent batch of 200 TW tires are supposedly almost like R-comps and better than the NT01's I've been running the past couple years since I got tired of changing tires twice a day during events. Anyway, plan is 15" rims and RE71R this year, next year some good coilovers and maybe after that a Torsen and go to STR or maybe back to CSP.

Instructions are posted online. I can get you a hardware list, but basically it's "enough 5/16" SS bolts to fill all the holes you drill".

As for classification, it could be argued these are armor for the chassis. A stock Miata frame rail is a weak, soft little thing. It was crushed rails that made us come up with these in the first place. These are strong enough to lift the car with.

I have heard a theory that if you extended them to attach to the subframes, they become subframe connectors and this changes their classification. I an not a rulebook expert so I don't know how legit that is.

Keith Tanner said:

As for classification, it could be argued these are armor for the chassis. A stock Miata frame rail is a weak, soft little thing. It was crushed rails that made us come up with these in the first place. These are strong enough to lift the car with.

While true (and you should see how much an RX-7's chassis rails can flex, too!), there isn't an endemic problem with the chassis that these are REQUIRED to keep it from being a consumable, in the same way that, say, MINI strut towers have.

As a general rule of thumb, for rallycross anyway, if you need to make permanent changes to the car such as drilling holes, it's not going to be allowable except in Mod.  Pretty much everything besides roll cage installation has the idea that everything is bolt-on upgrades.

Good to know that even without the cross-webbing this mod makes a significant difference. I was wondering.

What I did was to slice and dice and weld up a few 2 x4" pieces of tube to make a 1/8"  cladding along the entire length. The channel is seam welded along the top to the floor.  I also made  five 1.75" holes along the sides to attach to the sides of the original frame rail. The original plan was to make this strong enough to hold transmission mount. 

While it is theoretically a cheap and effective way to make the frame connectors, doing this without  the car on its side would suck unless you are really happy welding upside down.

The frame rails are great. Not only do they provide a great jacking point, they help with unexpected hoonery. 

Keith knows Hallet, years ago I had the Miata there running the "opposite direction" and went into The BI-CH too hot, and dropped a wheel on exit, hard hit, kept the throttle to the floor and kept going. 

Instead of caving in a frame rail, there was just a scrape. I'd show a picture but Photobucket is a bunch of assh----

If I have one concern about these for rally-cross, it's all those cavities collecting dirt and debris driving off road. 

I put the FM frame rails on my ‘04 and as cmcgregor noted, the result is transformative.  Based on Keith’s input, I didn’t opt for the butterfly as the NB2 has a lot of factory cross-bracing that does much, though not all, of the same thing.  I had to drill a couple extra holes to allow me to re-attach the rear-most factory cross brace, but that was a minor issue.  The benefit of the added rigidity is so impressive that its made me think about installing fender braces as well, but I’m balking at the amount of work that represents.  Call me a chicken...

On my '96 I have the frame rails with cross bracing and the fender bracing as well.

Makes a huge difference!