"They keep the pavement off your head" I do enjoy Keith's dry humor in these videos. These videos make me love my Miata just a little bit more. Thanks for taking the time to make them.
As a non-Miata owner… these technical videos are the best! Keep them coming. Been slowly going through all of the Facebook live videos that have been posted and they are by far the most informative and well explained on TH-cam. I also want a Miata more and more for some reason after watching these vids…
I was about to type more or less the same thing but you beat me to it! I've been subscribed to FM for around 8 months and even though I don't own, never have owned, and not really considering owning an MX5 (maybe a 4th gen in a few years when prices drop, or rather if prices drop with todays silly used car inflation), but there's no other TH-cam channels or automotive journalists that go this in depth and it's so useful for tuning my own car! Only other outlet that comes close is Hot Version, however the English subtitles can be unclear at times and their videos are short. Would be cool if they worked on different cars some day!
I don’t own one either but I anticipate buying one when the snow melts to replace my ES350. Looks like an unbelievably fun car for very little money, and I’m coming off a modded 350z
@@roddydykes7053 The degree to which Miatas have been documented, not just in the FM videos but also on the forums, is remarkable. Arguably the Miatas have been produced in greater numbers than any other light weight sports car. Just about any repair or modification to the car you might want to considered has been done many times by others, and discussions of these modifications exist on line. Both the factory and the after market parts availability for the car is extraordinary. This knowledge base, and this community, is a non-trivial benefit that comes with Miata ownership.
Please consider making a companion video to your diagrams for seam welding. Not necessary to actually weld anything, but have the areas uncovered, and talk about prep, after care, and approximate amount of "high effort".
Great video Keith, chassis stiffening is so underrated - I learned loads, thank you. I have a 1991 1.6 Eunos and funnily enough adding a roll bar helped with the 63mph jiggle. But what really made it disappear was installing door bars; I highly recommend them to anyone with an early 1.6 or even a 1.8. Keep up the great work - it's really appreciated by more people than you might think.
My experience is that an NA Miata, in the condition it rolled off the show-room floor, does not shimmy. If this is true, generally, as it was true for my car, then the closer the suspension parts are to 'as new' condition the more precise the handling, and the lower the chassis vibration will be. Ball joints lose stiffness long before they fail. I replace them every 30 or 40 thousand miles, not because they 'need' to be replaced but because I enjoy the precise handling that factory fresh suspension parts provide. Ball joints cost little and the job is a simple one. Many people seem to delay replacement of the upper front control arm bushings. Often they believe that it is necessary to replace the whole control arm. Moog, however, sells a bushing that presses into the factory control arm nicely. Also, I find that when bushings start to squeak they are ready to be replaced. I have replaced all of mine twice. Rubber hardens as it ages, and old, low mileage bushings will slip rather then flexing. Once they start to do this they wear quickly. I used urethane for a while. Even with Zerk fittings these are hard to keep lubricated, and then they squeak. I am currently using the IL bushings sold by Flyin' Miata, which I like very much. The IL bushings are slightly stiffer than stock, but not as stiff as a competition bushing. Replacing all the suspension bushings is a lot of work. With new IL bushings, new ball joints, fresh shocks, moderately sticky tires, a good alignment, and some chassis bracing you will have a car that is exceptionally nimble, even in comparison to some up-market cars famous for their agility. For chassis bracing, I am using Flyin' Miata's frame rails, a Cannon brace, and Racing Beat's front chassis brace and the Delrin door blocks. Collectively these made an enormous difference.
Shimmy complaints were common when NA Miatas were new, unfortunately. It's been a conversation in the Miata world for over 30 years. It's not all worn suspension parts.
The factory hardtop makes a massive difference in perceived chassis rigidity over bumps. It and the large rear window are the only reasons I like to run it because top down is more fun.
I hadn't realized you wrote those books. I don't know when I was last in a Barnes & Noble, but I remember seeing those books on the shelf, way back before I bought my NA6 Miata.
I could not believe how much of a difference the strong arms made on my K-swapped car. Cut down on vibration, and made the whole front end feel like it was doing what it was supposed to do. Frame rails are next!
We're obviously not biased ;) ... BUT, replacing suspension bushings on a vehicle, especially those on "Fun" cars can make such a difference. Ride, comfort, turn in, tyre life, resistance to oil etc (because some cars like to leak) are all benefited by changing to a Polyurethane bush, but even changing for a new OEM rubber bush will be and upgrade from the originals.
@Flyin' Miata Does improved chassis stiffness improve the longevity/durability of the car by any noticeable amount? You guys have been working on cars that have been on the road for many years, and I was wondering if you have notice if cars that had stiffness installed earlier in their life were healthier later on?
Enough to own a noodle shop. I noticed these harmonics symptoms at 62 mph and maybe another. I thought I saw the nose dive and hunker down a little more. So could be wrong but I concluded the front lip was designed to work harder as an air dam at faster than "normal" speeds. Bull's wool? 🤔
Got a 95 NA8 and see tire and rims being a big factor for the 65mph shimmy (even with new bushings, bearings, suspension, etc.). When having tires balanced at a shop I've found the ideal number is a road force value of 10 or less with 0 being ideal. Roadforce related to the vibration in the tire due to slight manufacturing discrepancies across the tires carcass. Anything more and the wheels and rims transmit the resonance vibration to the rear subframe then into the PPF upto the front of the car.
I’ve got a stock 95 M with the bbs, road forced and have zero shimmy. My 94R with various wheels, road force and tons of bracing has it. Luck of the draw but road force for the win!
Yeah had a nasty case of it on my '94 around, you guessed it, 65. Ultimately fixed through getting the best tire shop in town to do a proper road force balance on the wheels as well. Still very occasionally rears its ugly head, but it's at the point where it's so intermittent that I just haven't really bothered to chase it off. Figured that the bushings might also be playing into it (~170k miles on chassis and I'm 99% certain it's the same bushings the car left the factory with), but I haven't really bothered since I'm still debating moving up to a NB2 at some point.
I've seen people welding in the extra plate that reinforces the transmission tunnel and some of the metal behind the seats on an NB into an NA. Does this actually do anything for the chassis or is it more of a crash safety thing?
It should help - there are actually quite a few detail changes around the tunnel at both ends in the NB2 that contribute to the increases rigidity of that chassis. It's hard to say if it's worth the effort, though.
Absolutely loving these videos. Which steering wheel is that in the blue NA Miata? And where did you find that blue Mazda horn button? I didn’t see them on the website lol
From my internet research the best chassis stiffening mods you can do to the NA/NB is anything that braces the car longitudinal like the frame rails, door bars, fender braces and roll bar to some extent. The other braces can help but like Keith said at what point are you just adding more weight to the car instead of benefiting from a stiffer chassis. I would really like to drive a fully seam welded chassis and compare that to a fully braced one to see if there is any noticeable difference.
I have the Paco motorsports strong arms, FM sways front/rear, Koni yellows, FM springs, top-hats, brand new Storm S1's with road force balanced Conti extreme contact sport, upgraded door bushings, Hard dog rollbar, FM shock tower brace, new rotors/pads, checked/torqued all suspension components and I STILL get the 65mph 'shimmy'. About the only bracing left would be the frame rails w/butterfly bracing. Other than that, I am at a loss as to what fill fix it.
I think some cars are more prone to the 65 mph shimmy than others. Are you still on the stock suspension bushings? I noticed better ride quality when I upgraded my bushings but I wasn't focused on a certain road shimmy. I jump from 30 to 80 pretty quick😁
@@FlyinMiataVideo Yes, still on stock bushings. Perhaps that will be my next project, after I get my turbo kit(from you guys!), stageII airflow/fan/crossflow and coolant reroute installed. As far as the shimmy, it's only when I linger @65-ish. The traffic around here averaged 80 so I'm pretty smooth at that range, it's just one of those things that I'd like to resolve eventually.
Right on! It seems you've got a great upgrade list planned. Some cars may need more or less than others. My personal 1992 Miata was a vibrating mess before I threw all the chassis stiffening bits on it along with all new control arm bushings. It's now rock solid cruising at 65 mph. Feel free to send us an email or give us a call if you have any questions about it.@@Buzz65
We’re changing manufacturers of the front brace, and that also involves a redesign. I forgot that when I was shooting the video :) The new one will definitely include the lessons we’ve learned from 25 years of making shock tower braces with multiple generations, but it won’t be exactly like our current one. The area of the firewall that is usually used for triangulation is not a structural one - it’s just there to separate the engine bay from the gutter at the base of the windshield. Strut suspensions put fore-aft loads into the upper strut mounting points so that sort of triangulation is very useful, less so on our double wishbone front ends which mostly only see vertical loads there.
People on the forums report that aftermarket front subframe braces (for ND) makes a (positive) difference, however, no one has experience with them after installing the butterfly frame. People usually install everything all at once, or front subframes first then butterfly. My question is would having the butterfly brace make it unnecessary to install front subframe braces, or can benefits still be had for both? Also, I also read that the factory front subframe braces are flexible and in an area that is meant to crumple, and that getting into an accident or hitting a curb with stiffer aftermarket ones could cause more expensive damage to the chassis. Can you comment on this please?
The front subframe braces and butterfly braces are bracing different parts of the chassis. There are definitely benefits in applying both, as a stiffer chassis allows the suspension to work better and will keep the car flatter and more precise while cornering. We have not seen any crash testing on aftermarket bracing (besides roll-bars), so we can't comment there.
If anyone's doubtful it exists, I 100% have the 65 mph shimmy. I've read about and done the hunter roadforce tire balance and that does work for me, for a time, but after 6-8 months the vibration comes back until I get my tires meticulously balanced again. Coincidentally, my NA is missing some braces that I never got around to installing. Might be time to focus on stiffness
The frame rail braces with the butterfly brace makes a huge difference. Get someone to help you with it, I made the mistake of doing it by myself, it was a monumental pita.
I have FM frame rails to install. The problem is the PO has used the rails as jack points and had squashed them flat. Can the offending sections be cut out to facilitate installation of the FM frame stiffeners without weakening the structural integrity.
We usually recommend "assisting" the old frame rails into a shape that the new ones can fit over. C clamps to squeeze, hammers to move. If they're damaged badly enough, cutting them out might not be a problem. The new rails are far stiffer than the originals ever were.
The transmission tunnel was mentioned as the main stiffener, but there wasn't any proposal offered to increase its rigidity. Is there any effort in that area?
Can you comment on the effect of Nielex Pro Spec Knuckle Support on daily comfort/NVH for ND Miata? Anecdotes claim that steering feel/turn in response is improved but can only see real benefits at the limits of grip. Do these support the suspension in a way that allows the suspension to do more of what it’s designed to do and mitigate harshness from transmitting into the undamped spring that is chassis flex?
While we don't have direct experience with that part, the only thing it might do is prevent the knuckle from flexing under hard cornering loads. It's not going to affect harshness as it's really not in the load path from the wheel to the lower control arm to the shock.
@vfellas98 Thanks for watching! The rear shock tower braces aren't really necessary as those shock towers don't see cornering forces anywhere near as strong as the front of the car does.
What in your opinion is the best over all year to buy used? I personally like the looks of the mx-5 I've found a 2008 with 28k for 15k one owner and the fact that they r a little roomier.
If you have all of the factory bracing, we think that's pretty good for street performance. If it's a track-prepped car, you might look at IL Motorsports for their bracing options.
@@FlyinMiataVideo I have all the bracing (it's a 2.0), I wanted to know if with the under bracing il motorsport I can feel less noises with the poth holes and the cloth of the roof that moves on the metal support when I go in my box and the chassis twist a bit LoL.
i have the 65mph shimmy in my 99 model, its my 3rd 99 and i didnt have it in my other 2 cars. i wonder since everything runs in cycles at what speed the next occourance above 65mph would be....i would imagine it would be somewhere around 130mph
There's probably one more area worth discussing since you mentioned about the front crash bar under the bumper, will adding a torsion bar just before the rear bumper (two points between the rear tow hook) helps in improving chassis rigidity?
The big difference between the front and rear is the engine. In the rear, there's room for structure to span side to side - the subframe has multiple cross sections, there's the trunk floor and even the vertical skin of the unibody. All of that is missing on the front because there needs to be room to put a big chunk of engine up there along with associated parts and their airflow requirements. So while adding some bracing back there might help, it's more likely to help when applied directly to the subframe pickup points.
Late comer to this video. This is my first convertible. 2023 ND2 ST. I read the term cowl shake thrown around a lot. What is it? How do you know if you have it? What does it feel like? How does one minimize it? Thanks again
Cowl shake is basically the feeling that the front of the car is shaking in different directions from the passenger compartment, and it's most obvious at the base of the windshield and the hood - the cowl. The 2023 shouldn't have very much of it at all, it's more of a problem in the earlier cars. A shock tower brace that also connects to some significant structure on the firewall - like the factory ND one - is probably the best first step. If your ND doesn't have one from the factory, it can be retrofitted with some work.
What is the point of the Anti-roll bar in respect of the chassis, also anti- roll bars can be thicker & more robust. With poor constructed roads and potholes. Will the upgrades of making the miata more rigid, be better in protecting the suspension.
Keith has a couple of videos on suspension and the effects of sway bars. They will probably answer your question better than we can here: th-cam.com/video/wvqw-f4dhlA/w-d-xo.html th-cam.com/video/oYaoDgMCmtc/w-d-xo.html
I recently tracked my "stock" 91 NA. Used sticky tires (Yokohama A052) and 9kg/6kg coilovers. Had great traction and balance with a passenger, but when I drove alone in certain coners the back right wheel lifted and I couldn't get the power down. Is that necessarily a chassis stiffness problem and if yes is there a easy fix for it?
You might try adjusting your sway bar or softening your rear suspension to let the rear squat a tiny bit more in corners to help with grip. Keith doesn't run a rear sway bar on his V8 Miata to make sure he can get all the power down when he needs it. Feel free to give us a call if you need to talk through it or have a more in-depth conversation!
@@FlyinMiataVideo Thanks for the advice. I will definitely try taking out the rear bar during an event and see if it improves the grip while not messing too much with the overall balance. Do you guys think rake could also be a factor for my problem?
@@FlyinMiataVideo i know sometimes things appear one way but there are blindsides. my mind tells me it should stiffen the car some and offer some side impact protection. but my mind also tells me that with the car so low im probably imagining things. speaking of seats...Ive been hunting something "race inspired" that is decently made but have a reclining back and utilize the stock seat belt. I would be happy with a dang CG lock but you can;t get one anymore.....i just want some decent bolstering to hug me and stop me from moving so much and lower me down some for my off track driving. seems my request is unreasonable
If you can find one of our old butterfly designs, that should work. We don't have any of them left and they haven't been manufactured for a few years. The current design is unfortunately not compatible without welding new metal into the old frame rails.
Something I've noticed, having two separate NB2 Miatas, and going with the Flyin Miata butterfly brace each times Is that the V2 brace doesn't provide as much fore/aft rigidity as the V1 did. V1 effectively was a big X brace across the center of the car (makes it more triangularly braced) whereas V2 is more of a box with the front and rear separate cross supports. I definitely have more of the center console-meets-HVAC/dash panel squeak going over bumps in the road from the flex that I don't recall having my previous car. Any chance you guys will put out a template for a cross bar? There's a company called Oshcut that anyone can submit cad plans to and get laser cut metal made and shipped. I'd love to add a cross brace to mine using the existing bolt holes from the dual cross bars and really stiffen it up.
@@aygwm I could, I have AutoCAD, just getting accurate measurements would be easier with a lift. I recall FM actually mentioned having an idea for a flat aero panel that could bolt up to the rails so they have the designs in system that would be there and could be sold to people who wanted to take the known measurements and have it made. Instead of FM having to fabricate it themselves
Our testing on a rig showed the V2 to provide better torsional rigidity, so this is interesting feedback. I suspect there are some other differences between the cars that might be causing this noise. We don’t currently have any plans to publish models or measurements. The flat panel unfortunately didn’t give the results we wanted.
@@FlyinMiataVideo lateral rigidity does feel great, turn in is improved with the front and rear braces installed, just diagonally and longitudinally it's just not as good as the V1 in my opinion. I could feel the front and rear acting more cohesively in my old Miata with the V1 vs the new one with the V2 just seems to be just a hair looser. And the old NB had more miles when I bought it (47k bought-94k sold) on it than my 2nd NB has ever had (24k bought currently 28k).
Can chassis flex be beneficial and act to reduce NVH during daily street driving? I remember reading somewhere that Toyota kept with the C-channel frames on the Tacoma's instead of full box frames to maintain flex and articulation while rock crawling. The ND Base model (Sport in the US) doesn't come equipped with the shock tower brace. If I'm looking for max comfort, should I install one? What about all the other braces you mentioned?
Chassis flex may be beneficial when you're trying to make a car twist as far as possible - that's the rock crawling scenario - but it's not good for NVH because the chassis acts like a big undamped spring. That ND factory shock tower brace is well worthwhile for both handling and comfort. I have my doubts about the legitimacy of that Toyota story. It's more likely they want some flex to avoid cracking the chassis when overloaded - something that's much easier to do with a pickup than a sports car. Plus it's cheaper to make a C-channel frame.
@@FlyinMiataVideo would triangulated front strut braces (connecting between both strut towers and firewall) be ideal over ones that just connect between towers, or just from the shock tower to the firewall area, or is it overkill for daily driving?
@@richard-mai This is where the distinction between shock and strut becomes important. In a strut car, there are longitudinal loads on the strut towers due to braking and acceleration. On a double wishbone car with shocks (such as all Miatas), the loads are almost all vertical. So the need for fore-aft bracing is smaller. Add to that the fact that the firewall area used for these connections on an NA/NB is very thin and unsupported, and there's not much point to triangulating to it. On the NC and ND, Mazda added some better mounting points near the firewall so they're more likely to do something but the design of the cross bar and how it's mounted is still more important.
Was just looking to pick up a set of bronze Kogeki 17x8 and saw that they went out of stock. Is there any kind of timeline on the restock? Thanks a bunch!
Can't wait for the fall for the V2 frame rails and butterfly brace. This is how I progressed in my build. Delrin door bushings Strut tower bar Paco fender braces 15x8 wheels and ECS tires (game changer) Competition engine mounts Sway bars adjustable end Links and sway bar mount reinforcement block. Dave fab Jack bar Racing beat front control arm brace Canon brace Roadster sport PPF brace (one of my favorites) Now I just installed my rear Koni sports with FM springs. Still have to do the fronts. Lots of other mods that are not suspension and bracing related.
Is there any way we can pre-purchase a butterfly brace for whenever you get going with the new manufacturer and they come back in stock? Or is the pricing subject to change?
We don't take orders for products that are more than 30 days out. Since we don't have a solid date with the new manufacturer, we can't take orders at this time.
Question: if the main contributor to chassis flex is the car being a vert and a roll bar mostly benefits crash safety vs chassis stiffness, would a cage that is minimal (for ingress/egress), that bridges the gap created by the absence of the roof, greatly improve stiffness?
Yes, a cage can have a significant effect on chassis rigidity. The hard part is getting one into a Miata without it being too close to an unhelmeted head.
@@FlyinMiataVideo thanks for the response. I can see how that could be an issue. Maybe just bars that tie into the windshield frame, like the video says then. 👍🏼 Thanks!
you mentioned that mazda said the hardtop didn't add much rigidity on the NAs, but would you say this changes with the bolt-in hardtop brackets available now? I'd imagine a hardtop secured with metal brackets is stiffer than one clamped on with the oem plastic latches.
The OEM latches are metal all the way through, other than a small bit of nylon right at the nose. There's no squeaking when they're adjusted properly, so there certainly wasn't much movement with them. Solid metal brackets properly designed would probably improve things a bit, but most of them are designed more to restrain the hardtop instead of making it structural.
I have a 97 with the 65 mph shimmy. I have put in a rollbar, butterfly brace, frog arms and completely replaced/rebuilt the entire suspension with new Mazda parts or better (IL motorsport bushings, Koni shocks, Tein springs, etc). All the bracing reduced the problem but when I drive with the hard top it is completely gone, and this is a retrofitted one that didn't have the middle mounts. Referencing what Keith said, the hardtop may not improve rigidity but likely changes the chassis resonant frequency enough that it completely gets rid of the problem.
@@thunderbirdizations That's the intention of the door bushings, yes. It would be a challenge to make a hood strong enough but that's an interesting idea. It would require more, and more secure, mounting points which would make access more difficult.
@@FlyinMiataVideo sorry, asked before I got to that part of the video. Making my own hood (see profile), would some kindve long bushing under the entire outer hood work, with extra mounting points in the corners?
@@thunderbirdizations You'd definitely want to anchor at the corners and you'll want to minimize any possible slop on the hinges - or even replace them with strong pins like Aerocatches. Off the top of my head, you'd likely primarily want diagonal bracing joining the opposing corners where the mounting points are.
@@FlyinMiataVideo would love to see the Targa Miata back doing what it was built for with all the upgrades it has received over the years since the last time it raced The Rock. I watched every video you made about the race and it's what first made me purchase my 97 Miata. I have high hopes it will happen again in the future and I think it would be great content and R&D for future development. Also, it would be cool to see the Targa Miata and a ND chassis run it to see the differences on such a demanding course.
Keith almost went back with an ND in 2015, but Mazda’s lawyers got twitchy at the last moment! That comparison would definitely show the progress of the chassis, the suspension of the ND would be very useful in that event.
"They keep the pavement off your head" I do enjoy Keith's dry humor in these videos.
These videos make me love my Miata just a little bit more. Thanks for taking the time to make them.
How many times did I say "noodley"?
Looks like you were operating at a rate of about 12 NPH (noodles per hour) by my calculations
Doesn't the NC have the most stiff chassis?
great engineering talk about chassis. this video deserves more views. Not everyone is into miata's tech talk
As a non-Miata owner… these technical videos are the best! Keep them coming. Been slowly going through all of the Facebook live videos that have been posted and they are by far the most informative and well explained on TH-cam.
I also want a Miata more and more for some reason after watching these vids…
I was about to type more or less the same thing but you beat me to it!
I've been subscribed to FM for around 8 months and even though I don't own, never have owned, and not really considering owning an MX5 (maybe a 4th gen in a few years when prices drop, or rather if prices drop with todays silly used car inflation), but there's no other TH-cam channels or automotive journalists that go this in depth and it's so useful for tuning my own car!
Only other outlet that comes close is Hot Version, however the English subtitles can be unclear at times and their videos are short.
Would be cool if they worked on different cars some day!
I don’t own one either but I anticipate buying one when the snow melts to replace my ES350. Looks like an unbelievably fun car for very little money, and I’m coming off a modded 350z
@@roddydykes7053 The degree to which Miatas have been documented, not just in the FM videos but also on the forums, is remarkable. Arguably the Miatas have been produced in greater numbers than any other light weight sports car. Just about any repair or modification to the car you might want to considered has been done many times by others, and discussions of these modifications exist on line. Both the factory and the after market parts availability for the car is extraordinary. This knowledge base, and this community, is a non-trivial benefit that comes with Miata ownership.
Please consider making a companion video to your diagrams for seam welding. Not necessary to actually weld anything, but have the areas uncovered, and talk about prep, after care, and approximate amount of "high effort".
Great video Keith, chassis stiffening is so underrated - I learned loads, thank you.
I have a 1991 1.6 Eunos and funnily enough adding a roll bar helped with the 63mph jiggle. But what really made it disappear was installing door bars; I highly recommend them to anyone with an early 1.6 or even a 1.8. Keep up the great work - it's really appreciated by more people than you might think.
I wish we had a channel like this for the BMW E46 M3 !!
My experience is that an NA Miata, in the condition it rolled off the show-room floor, does not shimmy. If this is true, generally, as it was true for my car, then the closer the suspension parts are to 'as new' condition the more precise the handling, and the lower the chassis vibration will be. Ball joints lose stiffness long before they fail. I replace them every 30 or 40 thousand miles, not because they 'need' to be replaced but because I enjoy the precise handling that factory fresh suspension parts provide.
Ball joints cost little and the job is a simple one. Many people seem to delay replacement of the upper front control arm bushings. Often they believe that it is necessary to replace the whole control arm. Moog, however, sells a bushing that presses into the factory control arm nicely.
Also, I find that when bushings start to squeak they are ready to be replaced. I have replaced all of mine twice. Rubber hardens as it ages, and old, low mileage bushings will slip rather then flexing. Once they start to do this they wear quickly. I used urethane for a while. Even with Zerk fittings these are hard to keep lubricated, and then they squeak. I am currently using the IL bushings sold by Flyin' Miata, which I like very much. The IL bushings are slightly stiffer than stock, but not as stiff as a competition bushing.
Replacing all the suspension bushings is a lot of work. With new IL bushings, new ball joints, fresh shocks, moderately sticky tires, a good alignment, and some chassis bracing you will have a car that is exceptionally nimble, even in comparison to some up-market cars famous for their agility.
For chassis bracing, I am using Flyin' Miata's frame rails, a Cannon brace, and Racing Beat's front chassis brace and the Delrin door blocks. Collectively these made an enormous difference.
Shimmy complaints were common when NA Miatas were new, unfortunately. It's been a conversation in the Miata world for over 30 years. It's not all worn suspension parts.
Thanks, just bought your book after seeing this.
Right on!
The factory hardtop makes a massive difference in perceived chassis rigidity over bumps. It and the large rear window are the only reasons I like to run it because top down is more fun.
Love my FM frame rails, made a huge difference to my NA...cheers from NZ...
Great video. I'm going to do a full bare metal resto on my NA and I'm very tempted to add seam welding while I do it.
Definitely.
That would be the time to do it.
Helpful technical info. Well explained easy to understand how the Miata structure is. Looking forward to checking out the Flyin’ Miata parts for NA.
Worn out door hinges will negate any improvement you get from the door braces (delrin pucks)
I hadn't realized you wrote those books. I don't know when I was last in a Barnes & Noble, but I remember seeing those books on the shelf, way back before I bought my NA6 Miata.
I could not believe how much of a difference the strong arms made on my K-swapped car. Cut down on vibration, and made the whole front end feel like it was doing what it was supposed to do. Frame rails are next!
We're obviously not biased ;) ... BUT, replacing suspension bushings on a vehicle, especially those on "Fun" cars can make such a difference.
Ride, comfort, turn in, tyre life, resistance to oil etc (because some cars like to leak) are all benefited by changing to a Polyurethane bush, but even changing for a new OEM rubber bush will be and upgrade from the originals.
Very true!
Great vid! I need one of those flyin miata stickers for my bar.
What about the possibility of rust for the frame rail bars?
@Flyin' Miata
Does improved chassis stiffness improve the longevity/durability of the car by any noticeable amount? You guys have been working on cars that have been on the road for many years, and I was wondering if you have notice if cars that had stiffness installed earlier in their life were healthier later on?
Love the idea of adding bracing but when will the butterfly braces be back in stock? They have been out for a while.
We are moving to a new manufacturer for that part. They're in production now but we don't have a solid date for when they'll be on the shelf.
Very informative
Enough to own a noodle shop. I noticed these harmonics symptoms at 62 mph and maybe another. I thought I saw the nose dive and hunker down a little more. So could be wrong but I concluded the front lip was designed to work harder as an air dam at faster than "normal" speeds. Bull's wool? 🤔
Got a 95 NA8 and see tire and rims being a big factor for the 65mph shimmy (even with new bushings, bearings, suspension, etc.). When having tires balanced at a shop I've found the ideal number is a road force value of 10 or less with 0 being ideal. Roadforce related to the vibration in the tire due to slight manufacturing discrepancies across the tires carcass. Anything more and the wheels and rims transmit the resonance vibration to the rear subframe then into the PPF upto the front of the car.
I’ve got a stock 95 M with the bbs, road forced and have zero shimmy. My 94R with various wheels, road force and tons of bracing has it. Luck of the draw but road force for the win!
Yeah had a nasty case of it on my '94 around, you guessed it, 65. Ultimately fixed through getting the best tire shop in town to do a proper road force balance on the wheels as well. Still very occasionally rears its ugly head, but it's at the point where it's so intermittent that I just haven't really bothered to chase it off. Figured that the bushings might also be playing into it (~170k miles on chassis and I'm 99% certain it's the same bushings the car left the factory with), but I haven't really bothered since I'm still debating moving up to a NB2 at some point.
I've seen people welding in the extra plate that reinforces the transmission tunnel and some of the metal behind the seats on an NB into an NA. Does this actually do anything for the chassis or is it more of a crash safety thing?
It should help - there are actually quite a few detail changes around the tunnel at both ends in the NB2 that contribute to the increases rigidity of that chassis. It's hard to say if it's worth the effort, though.
Absolutely loving these videos. Which steering wheel is that in the blue NA Miata? And where did you find that blue Mazda horn button? I didn’t see them on the website lol
The wheel is a Momo Prototipo, and the horn button is a custom piece from Revlimiter.
From my internet research the best chassis stiffening mods you can do to the NA/NB is anything that braces the car longitudinal like the frame rails, door bars, fender braces and roll bar to some extent. The other braces can help but like Keith said at what point are you just adding more weight to the car instead of benefiting from a stiffer chassis.
I would really like to drive a fully seam welded chassis and compare that to a fully braced one to see if there is any noticeable difference.
Did you say that there is an instruction for the areas to seam weld on your website?
help.flyinmiata.com/en_us/lots-of-pain-a-little-gain-BkYvAnA3s
I have the Paco motorsports strong arms, FM sways front/rear, Koni yellows, FM springs, top-hats, brand new Storm S1's with road force balanced Conti extreme contact sport, upgraded door bushings, Hard dog rollbar, FM shock tower brace, new rotors/pads, checked/torqued all suspension components and I STILL get the 65mph 'shimmy'. About the only bracing left would be the frame rails w/butterfly bracing. Other than that, I am at a loss as to what fill fix it.
I think some cars are more prone to the 65 mph shimmy than others. Are you still on the stock suspension bushings? I noticed better ride quality when I upgraded my bushings but I wasn't focused on a certain road shimmy. I jump from 30 to 80 pretty quick😁
@@FlyinMiataVideo Yes, still on stock bushings. Perhaps that will be my next project, after I get my turbo kit(from you guys!), stageII airflow/fan/crossflow and coolant reroute installed. As far as the shimmy, it's only when I linger @65-ish. The traffic around here averaged 80 so I'm pretty smooth at that range, it's just one of those things that I'd like to resolve eventually.
Right on! It seems you've got a great upgrade list planned.
Some cars may need more or less than others. My personal 1992 Miata was a vibrating mess before I threw all the chassis stiffening bits on it along with all new control arm bushings. It's now rock solid cruising at 65 mph. Feel free to send us an email or give us a call if you have any questions about it.@@Buzz65
When's the FM front shock tower brace coming out? Will it be triangulated to the firewall or is there not enough structural rigidity up high?
They had a shock tower brace that they discontinued.
@@aygwm I thought that was the case, was surprised to hear Keith make a case for the front brace. Perhaps Keith will weigh in?
We’re changing manufacturers of the front brace, and that also involves a redesign. I forgot that when I was shooting the video :) The new one will definitely include the lessons we’ve learned from 25 years of making shock tower braces with multiple generations, but it won’t be exactly like our current one.
The area of the firewall that is usually used for triangulation is not a structural one - it’s just there to separate the engine bay from the gutter at the base of the windshield. Strut suspensions put fore-aft loads into the upper strut mounting points so that sort of triangulation is very useful, less so on our double wishbone front ends which mostly only see vertical loads there.
@@FlyinMiataVideo excellent, on the Wish List it will go. My NB is a rolling FM cart 😏
@@FlyinMiataVideo will it allow for the use of the clutch master cylinder brace?
Thanks for another good one!
People on the forums report that aftermarket front subframe braces (for ND) makes a (positive) difference, however, no one has experience with them after installing the butterfly frame. People usually install everything all at once, or front subframes first then butterfly.
My question is would having the butterfly brace make it unnecessary to install front subframe braces, or can benefits still be had for both?
Also, I also read that the factory front subframe braces are flexible and in an area that is meant to crumple, and that getting into an accident or hitting a curb with stiffer aftermarket ones could cause more expensive damage to the chassis. Can you comment on this please?
The front subframe braces and butterfly braces are bracing different parts of the chassis. There are definitely benefits in applying both, as a stiffer chassis allows the suspension to work better and will keep the car flatter and more precise while cornering. We have not seen any crash testing on aftermarket bracing (besides roll-bars), so we can't comment there.
If anyone's doubtful it exists, I 100% have the 65 mph shimmy. I've read about and done the hunter roadforce tire balance and that does work for me, for a time, but after 6-8 months the vibration comes back until I get my tires meticulously balanced again. Coincidentally, my NA is missing some braces that I never got around to installing. Might be time to focus on stiffness
The frame rail braces with the butterfly brace makes a huge difference. Get someone to help you with it, I made the mistake of doing it by myself, it was a monumental pita.
I have FM frame rails to install. The problem is the PO has used the rails as jack points and had squashed them flat. Can the offending sections be cut out to facilitate installation of the FM frame stiffeners without weakening the structural integrity.
We usually recommend "assisting" the old frame rails into a shape that the new ones can fit over. C clamps to squeeze, hammers to move. If they're damaged badly enough, cutting them out might not be a problem. The new rails are far stiffer than the originals ever were.
The transmission tunnel was mentioned as the main stiffener, but there wasn't any proposal offered to increase its rigidity. Is there any effort in that area?
That’s effectively what the butterfly brace does, as it closes the box on the tunnel.
“Because you can never be too stiff” is a perfect example of what she said. 😂
Can you comment on the effect of Nielex Pro Spec Knuckle Support on daily comfort/NVH for ND Miata? Anecdotes claim that steering feel/turn in response is improved but can only see real benefits at the limits of grip. Do these support the suspension in a way that allows the suspension to do more of what it’s designed to do and mitigate harshness from transmitting into the undamped spring that is chassis flex?
While we don't have direct experience with that part, the only thing it might do is prevent the knuckle from flexing under hard cornering loads. It's not going to affect harshness as it's really not in the load path from the wheel to the lower control arm to the shock.
So would you say a rear Strut Bar is wasted Money because it is super stuff in the chassis back there anyway? Talking about the NC. Thanks!
@vfellas98 Thanks for watching! The rear shock tower braces aren't really necessary as those shock towers don't see cornering forces anywhere near as strong as the front of the car does.
What in your opinion is the best over all year to buy used? I personally like the looks of the mx-5 I've found a 2008 with 28k for 15k one owner and the fact that they r a little roomier.
For the ND which are in order the braces that make major difference? I have Ohlins coilover and I'm thinking to put underbraces.
If you have all of the factory bracing, we think that's pretty good for street performance. If it's a track-prepped car, you might look at IL Motorsports for their bracing options.
@@FlyinMiataVideo I have all the bracing (it's a 2.0), I wanted to know if with the under bracing il motorsport I can feel less noises with the poth holes and the cloth of the roof that moves on the metal support when I go in my box and the chassis twist a bit LoL.
i have the 65mph shimmy in my 99 model, its my 3rd 99 and i didnt have it in my other 2 cars. i wonder since everything runs in cycles at what speed the next occourance above 65mph would be....i would imagine it would be somewhere around 130mph
There's probably one more area worth discussing since you mentioned about the front crash bar under the bumper, will adding a torsion bar just before the rear bumper (two points between the rear tow hook) helps in improving chassis rigidity?
The big difference between the front and rear is the engine. In the rear, there's room for structure to span side to side - the subframe has multiple cross sections, there's the trunk floor and even the vertical skin of the unibody. All of that is missing on the front because there needs to be room to put a big chunk of engine up there along with associated parts and their airflow requirements.
So while adding some bracing back there might help, it's more likely to help when applied directly to the subframe pickup points.
Thoughts on seam welding just the door jambs? Any tips?
Late comer to this video. This is my first convertible. 2023 ND2 ST. I read the term cowl shake thrown around a lot. What is it? How do you know if you have it? What does it feel like? How does one minimize it? Thanks again
Cowl shake is basically the feeling that the front of the car is shaking in different directions from the passenger compartment, and it's most obvious at the base of the windshield and the hood - the cowl. The 2023 shouldn't have very much of it at all, it's more of a problem in the earlier cars. A shock tower brace that also connects to some significant structure on the firewall - like the factory ND one - is probably the best first step. If your ND doesn't have one from the factory, it can be retrofitted with some work.
I appreciate your speedy response
@ flinmiata
I've been looking to buy your front tower brace but is not listed on your web site?
These are temporarily unavailable while we work on a new design, but we are hoping to have them again soon! So sorry for the hassle!
What is the point of the Anti-roll bar in respect of the chassis, also anti- roll bars can be thicker & more robust. With poor constructed roads and potholes. Will the upgrades of making the miata more rigid, be better in protecting the suspension.
Keith has a couple of videos on suspension and the effects of sway bars. They will probably answer your question better than we can here:
th-cam.com/video/wvqw-f4dhlA/w-d-xo.html
th-cam.com/video/oYaoDgMCmtc/w-d-xo.html
For a 2001 nb which is the best choice under transmition?
I recently tracked my "stock" 91 NA. Used sticky tires (Yokohama A052) and 9kg/6kg coilovers.
Had great traction and balance with a passenger, but when I drove alone in certain coners the back right wheel lifted and I couldn't get the power down.
Is that necessarily a chassis stiffness problem and if yes is there a easy fix for it?
You might try adjusting your sway bar or softening your rear suspension to let the rear squat a tiny bit more in corners to help with grip. Keith doesn't run a rear sway bar on his V8 Miata to make sure he can get all the power down when he needs it. Feel free to give us a call if you need to talk through it or have a more in-depth conversation!
@@FlyinMiataVideo Thanks for the advice. I will definitely try taking out the rear bar during an event and see if it improves the grip while not messing too much with the overall balance.
Do you guys think rake could also be a factor for my problem?
what are you guys thoughts on the Hard Dog side rail bars?
It’s not a great place to have an unpadded steel bar with a stock seat.
@@FlyinMiataVideo i know sometimes things appear one way but there are blindsides. my mind tells me it should stiffen the car some and offer some side impact protection. but my mind also tells me that with the car so low im probably imagining things. speaking of seats...Ive been hunting something "race inspired" that is decently made but have a reclining back and utilize the stock seat belt. I would be happy with a dang CG lock but you can;t get one anymore.....i just want some decent bolstering to hug me and stop me from moving so much and lower me down some for my off track driving. seems my request is unreasonable
a good foamectomy will make your stock seats more comfortable, lower and give you more lateral support. We did a video on it a few years back.
Pretty sure I have V1 framerails, what are my options for a butterfly brace?
If you can find one of our old butterfly designs, that should work. We don't have any of them left and they haven't been manufactured for a few years. The current design is unfortunately not compatible without welding new metal into the old frame rails.
Something I've noticed, having two separate NB2 Miatas, and going with the Flyin Miata butterfly brace each times
Is that the V2 brace doesn't provide as much fore/aft rigidity as the V1 did.
V1 effectively was a big X brace across the center of the car (makes it more triangularly braced) whereas V2 is more of a box with the front and rear separate cross supports.
I definitely have more of the center console-meets-HVAC/dash panel squeak going over bumps in the road from the flex that I don't recall having my previous car.
Any chance you guys will put out a template for a cross bar? There's a company called Oshcut that anyone can submit cad plans to and get laser cut metal made and shipped.
I'd love to add a cross brace to mine using the existing bolt holes from the dual cross bars and really stiffen it up.
Why not design one yourself?
@@aygwm I could, I have AutoCAD, just getting accurate measurements would be easier with a lift. I recall FM actually mentioned having an idea for a flat aero panel that could bolt up to the rails so they have the designs in system that would be there and could be sold to people who wanted to take the known measurements and have it made. Instead of FM having to fabricate it themselves
Our testing on a rig showed the V2 to provide better torsional rigidity, so this is interesting feedback. I suspect there are some other differences between the cars that might be causing this noise.
We don’t currently have any plans to publish models or measurements. The flat panel unfortunately didn’t give the results we wanted.
@@FlyinMiataVideo lateral rigidity does feel great, turn in is improved with the front and rear braces installed, just diagonally and longitudinally it's just not as good as the V1 in my opinion.
I could feel the front and rear acting more cohesively in my old Miata with the V1 vs the new one with the V2 just seems to be just a hair looser. And the old NB had more miles when I bought it (47k bought-94k sold) on it than my 2nd NB has ever had (24k bought currently 28k).
Are frame rail braces worthwhile? I have a 99.
Definitely.
Can chassis flex be beneficial and act to reduce NVH during daily street driving? I remember reading somewhere that Toyota kept with the C-channel frames on the Tacoma's instead of full box frames to maintain flex and articulation while rock crawling.
The ND Base model (Sport in the US) doesn't come equipped with the shock tower brace. If I'm looking for max comfort, should I install one? What about all the other braces you mentioned?
Chassis flex may be beneficial when you're trying to make a car twist as far as possible - that's the rock crawling scenario - but it's not good for NVH because the chassis acts like a big undamped spring. That ND factory shock tower brace is well worthwhile for both handling and comfort.
I have my doubts about the legitimacy of that Toyota story. It's more likely they want some flex to avoid cracking the chassis when overloaded - something that's much easier to do with a pickup than a sports car. Plus it's cheaper to make a C-channel frame.
@@FlyinMiataVideo thank you!
@@FlyinMiataVideo would triangulated front strut braces (connecting between both strut towers and firewall) be ideal over ones that just connect between towers, or just from the shock tower to the firewall area, or is it overkill for daily driving?
@@richard-mai This is where the distinction between shock and strut becomes important. In a strut car, there are longitudinal loads on the strut towers due to braking and acceleration. On a double wishbone car with shocks (such as all Miatas), the loads are almost all vertical. So the need for fore-aft bracing is smaller. Add to that the fact that the firewall area used for these connections on an NA/NB is very thin and unsupported, and there's not much point to triangulating to it. On the NC and ND, Mazda added some better mounting points near the firewall so they're more likely to do something but the design of the cross bar and how it's mounted is still more important.
@@FlyinMiataVideo wow learned something new about shocks/struts. Thanks again!
Was just looking to pick up a set of bronze Kogeki 17x8 and saw that they went out of stock. Is there any kind of timeline on the restock? Thanks a bunch!
If we have an ETA from the supplier, it's visible on the website. If there's no ETA listed, that means we don't have one that's reliable at this time.
@@FlyinMiataVideo okay, thank you anyways!
Can't wait for the fall for the V2 frame rails and butterfly brace.
This is how I progressed in my build.
Delrin door bushings
Strut tower bar
Paco fender braces
15x8 wheels and ECS tires (game changer)
Competition engine mounts
Sway bars adjustable end Links and sway bar mount reinforcement block.
Dave fab Jack bar
Racing beat front control arm brace
Canon brace
Roadster sport PPF brace (one of my favorites)
Now I just installed my rear Koni sports with FM springs. Still have to do the fronts.
Lots of other mods that are not suspension and bracing related.
What’s your feedback on the PPF brace?
Is there any way we can pre-purchase a butterfly brace for whenever you get going with the new manufacturer and they come back in stock? Or is the pricing subject to change?
We don't take orders for products that are more than 30 days out. Since we don't have a solid date with the new manufacturer, we can't take orders at this time.
@@FlyinMiataVideo Fair enough, thanks for the reply!
Question: if the main contributor to chassis flex is the car being a vert and a roll bar mostly benefits crash safety vs chassis stiffness, would a cage that is minimal (for ingress/egress), that bridges the gap created by the absence of the roof, greatly improve stiffness?
Yes, a cage can have a significant effect on chassis rigidity. The hard part is getting one into a Miata without it being too close to an unhelmeted head.
@@FlyinMiataVideo thanks for the response. I can see how that could be an issue. Maybe just bars that tie into the windshield frame, like the video says then. 👍🏼
Thanks!
you mentioned that mazda said the hardtop didn't add much rigidity on the NAs, but would you say this changes with the bolt-in hardtop brackets available now? I'd imagine a hardtop secured with metal brackets is stiffer than one clamped on with the oem plastic latches.
The OEM latches are metal all the way through, other than a small bit of nylon right at the nose. There's no squeaking when they're adjusted properly, so there certainly wasn't much movement with them. Solid metal brackets properly designed would probably improve things a bit, but most of them are designed more to restrain the hardtop instead of making it structural.
You can bend the hardtop by hand… so it doesn’t add much.
@@aygwm lol true, probably the reason why mine's bowed at the top
I have a 97 with the 65 mph shimmy. I have put in a rollbar, butterfly brace, frog arms and completely replaced/rebuilt the entire suspension with new Mazda parts or better (IL motorsport bushings, Koni shocks, Tein springs, etc). All the bracing reduced the problem but when I drive with the hard top it is completely gone, and this is a retrofitted one that didn't have the middle mounts. Referencing what Keith said, the hardtop may not improve rigidity but likely changes the chassis resonant frequency enough that it completely gets rid of the problem.
What can i do to limitate the mx5 nd rolling? I would like it a bit more flat.
Sway bars.
@@FlyinMiataVideo only one sway bar at the rear can help?
C70 has entered the chat.
Is it possible to somehow leverage the doors or hood to “close the box?”
Aftermarket structurely strong hood
10:02
@@thunderbirdizations That's the intention of the door bushings, yes. It would be a challenge to make a hood strong enough but that's an interesting idea. It would require more, and more secure, mounting points which would make access more difficult.
@@FlyinMiataVideo sorry, asked before I got to that part of the video.
Making my own hood (see profile), would some kindve long bushing under the entire outer hood work, with extra mounting points in the corners?
@@thunderbirdizations You'd definitely want to anchor at the corners and you'll want to minimize any possible slop on the hinges - or even replace them with strong pins like Aerocatches. Off the top of my head, you'd likely primarily want diagonal bracing joining the opposing corners where the mounting points are.
do nb front strut braces fit na's?
Sometimes. The NB has a slightly taller hood line and a taller engine in some variations, so an NB specific brace may make contact with an NA hood.
Will Flyin Miata ever return to run the Targa race again
Never say never, but it's not in our current plans. It's a pretty big commitment on the part of both the company and the team.
@@FlyinMiataVideo would love to see the Targa Miata back doing what it was built for with all the upgrades it has received over the years since the last time it raced The Rock. I watched every video you made about the race and it's what first made me purchase my 97 Miata. I have high hopes it will happen again in the future and I think it would be great content and R&D for future development. Also, it would be cool to see the Targa Miata and a ND chassis run it to see the differences on such a demanding course.
Keith almost went back with an ND in 2015, but Mazda’s lawyers got twitchy at the last moment! That comparison would definitely show the progress of the chassis, the suspension of the ND would be very useful in that event.
Important for the loser moment of inertia