NA6 / NA8 front swaybar geometry and effect of NA8 fitted to NA6 vehicle

[plohl]

be careful with a lot of the american feed back as well. Mx5's are used for heaps of autocross events over there, so set ups can definitely lean toward that - which is a stiff rear end to get it around the super tight tracks.

Whiteline have a sale on at the moment, 20% off apparently.

RS2000's sway bars might have been a bit more if he had them custom made buy signature. I assume the ones main are selling about the 24 and 16mm ones. Signature would probably sell a lot more if they made the rears 14mm.

[twr7cx]

Whiteline have a sale on at the moment, 20% off apparently.

Yep, GRIP20 is the checkout code to use on their website. Not sure when it expires though.

I assume the ones main are selling about the 24 and 16mm ones. Signature would probably sell a lot more if they made the rears 14mm.

I'll advise once I hear back from MX5 Mania Motorsports - perhaps on Tuesday when they reopen.

[RS2000]

RS2000's sway bars might have been a bit more if he had them custom made buy signature. I assume the ones main are selling about the 24 and 16mm ones. Signature would probably sell a lot more if they made the rears 14mm.

?? 14mm rear is what they made for me. I might be wrong, but I got the impression that Signature only make to order, so all are custom made in the sizes you want.

[twr7cx]

I might be wrong, but I got the impression that Signature only make to order, so all are custom made in the sizes you want.

Will find out on Tuesday when businesses reopen and advise the outcome.


I had a thought today. The vehicle as Flyin' Miata Improved Bump Stops https://www.flyinmiata.com/improved-bump-stops.html and Flyin' Miata Rear Shock Mounts https://www.flyinmiata.com/1990-97-flyi ... ounts.html fitted to what is an otherwise stock standard suspension (struts, coil springs and swaybars) - would this perhaps have increased the vehicle being more 'rolly-polly' than ordinary stock standard setups'?
My thought behind this, and reason for asking, is that I've read the Miata's use the bump stops as part of the suspension more than other vehicles do and it's not uncommon on the standard setups to be on them during hard corners. So if the Improved Bump Stops are shorter than the OEM units (which I believe they are at 54mm in length), I assume therefore the spring and strut would need to compress a bit further before the bump stop starts limiting the suspensions travel (meaning the vehicle rolls over further in a hard corder). Then in addition, I believe they're an increasing progressive rate unlike the OEM ones which I read are a linear hard rate, so there may be some further compression of the bump stop in the initial softer progressive part (so the vehicle is rolling over even a bit further again).
Likewise with the Rear Shock Mounts, they increase the shock travel by raising the bump stop up into a recess increasing the amount the strut can travel before the bump stop makes contact. Again isn't this increasing the amount that the rear spring and strut need to compress before the bump stop comes into play (meaning the vehicle rolls over further again in a hard corner)?

[manga_blue]

Sway bar arm lengths.jpg

[twr7cx]

RS2000's sway bars might have been a bit more if he had them custom made buy signature. I assume the ones main are selling about the 24 and 16mm ones. Signature would probably sell a lot more if they made the rears 14mm.

?? 14mm rear is what they made for me. I might be wrong, but I got the impression that Signature only make to order, so all are custom made in the sizes you want.

Spoke to Ajay at MX5 Mania Motorsport and he advised 24mm front and 16mm rear for their Signature Swaybars. But can get othersizes made up.

Spoke to directly to Todd at Signature Swaybars and he advised he can made them up, 3 - 4 week wait period though. Pricing for 22mm front and 14mm rear is:
Front fixed (non-adjustable) - $269.00
Front adjustable - $291.00
Rear fixed - $236.00
Rear adjustable - $253.00

The custom sizing seems to add a bit to the price as MX5 Mania Motorsport are offering them at $235.00 a pop on their website https://mx5mania.com.au/products/nc-198 ... 4376981538 in the larger diameter.

I've got a set being made up in yellow. And ordered the adjustable Super Miata SwayBar Links from MX5 Mania Motorsports.

[twr7cx]

While waiting for the Signature Swaybars I perhaps got a little bit over excited. As of this evening the vehicle is back assembled and due for a wheel alignment, it's now fitted with:
Signature Swaybars - 22mm adjustable front set to middle medium setting and 14mm adjustable rear set to middle medium setting.
SuperMiata End Links < https://supermiata.com/SuperMiata-miata-end-links.aspx >.
TEIN EnduraPro Plus shock absorbers < https://www.tein.com/products/endurapro.html > with 16 Level Dampening Fore Adjustment. Currently set to level 8 all around as per TEIN's starting recommendation. Still using the Flyin'Miata short bump stops and rear long travel shock tops.
King Spring Standard coil springs - Front KMFS-52 230lb/in and Rear KMRS-53 140lb/in (I believe a bit higher spring rate than standard) - they've raised the vehicle 15mm from the old NA6 standard springs which is very practical as no longer grinds on the frame rails going over the lip to get into the workshop or rubs on my washed out dirt driveway. I also picked up a set of their Low Springs that I'll keep aside for the future if I ever want to drop it for looks or if practicalities don't matter.

Took it for a quick spin, as it needs a wheel alignment, the rolly polly nature has changed, it's not a flat stiff car, it still leans, but it doesn't seem to just flop from side to side now which feels much nicer and I prefer.

Any thoughts on settings for the wheel alignment?

[plohl]

The supermiata alignment guide is a pretty good start.

https://supermiata.com/miata-race-alignment-info.aspx

Supermiata Street Alignment

For most street dríven Miatas, tire wear is the most important parameter. Excess toe in or out will usually cause more tire wear than somewhat aggressive camber will. The OEM alignment numbers with more rear camber than in front, are designed to induce a bit of understeer. Lawyers ultimately dictate the OEM alignment, not the clever engineeers that designed the suspension. The actual suspension geometry is designed to require greater front than rear camber. The SuperMiata Street Alignment will generally result in no increase in tire wear over OEM and possibly a reduction in tire wear if you occasionally load the tires to maximum cornering forces. In general, this Street alignment is conservative and intended for cars that never slide their tires and spend almost no time at maximum conrnering loads.

NOTE: This alignment will require a slightly larger front sway bar. NB factory, FM or Racing Beat 1" solid bars will work. The Racing Beat 1.125 bar is too much for normal street tires (>240 treadwear). The Street Alignment may cause a 100% stock Miata to oversteer, or be too "loose" so it is recommended to use the front sway bars described here.

5.00 ~ 5.5" front pinch weld height
.06 ~ .18" rake, rear higher
(Exocet - .4" rake, rear lower)

Front camber: -1.4°

Caster: >4.5°
Front total toe: +1/16" (.06")

Rear camber : -1°
Rear total toe: +1/8" (.12")

[twr7cx]

The supermiata alignment guide is a pretty good start.

https://supermiata.com/miata-race-alignment-info.aspx

Thanks, I had read that and a few of the other popular ones around. A few conflicting opinions within them:

Camber:

Miq's Miata.net Alignment, Factory recommended alignment, Icehawk's Alignment Spec < https://www.miata.net/garage/align.html > and Flyin'Miata (FM) < https://www.flyinmiata.com/support/inst ... stands.pdf > all have the rear with around 0.5* more negative camber than the front. The average seems to be -1 front and -1.5 rear. with an explanation being:

Because the front tires turn, less camber is desired on them as it effects other characteristics

SuperMiata however suggest the opposite of with more negative camber than rear (-1.4* front and -1* rear) with their explanation being:

The OEM alignment numbers with more rear camber than in front, are designed to induce a bit of understeer. Lawyers ultimately dictate the OEM alignment, not the clever engineeers that designed the suspension. The actual suspension geometry is designed to require greater front than rear camber.

Toe:

Again some differing opinions here:
Factory specs, SuperMiata and Flyin'Miata uses toe in (positive) front and rear.
Miq's and Icehawk recommend toe out front and toe in rear with their explanation of:

In the rear, toe out is bad, it won't help the car any, even to understeer.
The front wheels actually like a bit of toe out, about the same measurements. This helps to counteract the effects of all that positive caster.
If you decide that tire life should not be sacrificed for magnificent handling, then setting toe fore and aft to zero is a good safe route to go.

Having read through various threads and guides this is what I'm thinking I'll try:

Front:

Front Caster: hopefully at least +4.2°. More is better but may need to sacrifice additional caster to achieve the camber specs.
The best way to set up caster and camber on the front wheels is to have the shop give you as much positive caster as physically possible, then dial in the maximum negative camber while keeping the caster. It is possible to see numbers like 4.7° to 5.5° degrees positive caster depending on the year and ride height of the Miata.

Front Camber: -0.7° - more is better
(Front camber should be -0.4 to -0.5° less than the rear)

Front total toe: between 0 and 1.6mm (0.06”, 1/16", 0.15° or 9 arcminutes) total toe in
0.8mm, 1/32", 0.075° or 4.5 arcminutes per side

Rear

Rear Camber: -1.1 - -1.5° - more is better
(Rear camber should be -0.4 to -0.5° more than the front)

Rear total toe: 1.6mm (0.06”, 1/16", 0.15° or 9 arcminutes) total toe in
0.8mm, 1/32", 0.075° or 4.5 arcminutes per side

[plohl]

It's almost down the preference really. You're not at the track, so probably the most important thing is you want the car to steer fairly straight and not dart around/track on the road.

They're probably recommending different things like toe out on the front with more rear camber because it pushes more with extra rear camber, so they're trying to get it to turn in better with the extra toe.
The rear gains more camber than the front in roll, so that's why 949 have less rear camber, so it's almost equal when cornering... in a hand wavey kinda way.

I've always found toe out at the front makes the car dart around under brakes at the race track, but others swear by it.

I would say go with the 949 settings personally. I've dríven on the road with... lots... of different settings, more rear camber, less rear cambers, toe out, toe in... Always been a fan of about 0.5* less rear camber and 0 toe all round with the standard engine.

Probably should make sure whoever does the wheel alignment is able and willing to give you what you ask for, else you'll get 0 camber all round and 2mm toe in front and rear.

Let us know how you go with above settings. Can always go back after a month and try something else if you're not happy with it.

[twr7cx]

Probably should make sure whoever does the wheel alignment is able and willing to give you what you ask for, else you'll get 0 camber all round and 2mm toe in front and rear.

I hope they should be able to achieve. Heading to the large Bridgestone dealer first thing Monday morning. Chatted to them on the phone during the week and they're going to let me sit in the car so that it can be aligned at proper road going height with half tank of fuel and drivers weight.

[twr7cx]

Thanks for the chat all and sharing your advice, guidance and thoughts. I'm super happy with the current setup. It also offers me flexibility to drop it in the future if I so desire (I have a set of King Spring lows sitting on the shelf) but the standard ride height is very practical for the cars current use and along with the slightly increased spring rates, thicker swaybars and superior shock absorbers it seems far more controlled in it's corner lean in rather than the rolly polly previously experienced.