Rear subframe brace - NA

[sailaholic]

Why not see if you can get the nuts put in the factory place and get the later model factory bracing from a wreck for sweet all.

Sent from my GT-I9100 using Tapatalk 2

[ralt]

Hi.
The rear brace you showed will work well and together with a front brace you will feel the extra rigidity. The only problem I found with that brace was that it hung down too low where it is bent. I modified mine and then made another very easy job. If you have a good vice,file,drill and if needed a hacksaw to split one side of the tube before flattening its not rocket science. Also just remember Mazda spent ten of millions of yen designing and executing the bracing for the clubman and surprise surprise its all bolt on.

[93_Clubman]

A few years ago Davamb had some 4 point braces made locally:
viewtopic.php?f=44&t=38542
viewtopic.php?f=44&t=37528
viewtopic.php?f=30&t=28511

Bensale then took over for a while:
viewtopic.php?f=44&t=39770
viewtopic.php?f=44&t=39423

Neither have them made any more due to busy lives & other commitments, but nothing to stop you getting one made as there should be enough detail in the threads to assist.

[KevGoat]

You asked for people's impressions of what they have actually changed rather than just opinions, so here goes

I own a 1990 NA. I don't track my car. My chase in suspension/bracing is for comfort and daily practicality, with good road handling for the occasional quick twisty sections. I am also chasing a reduction of chassis/suspension vibrations as these reduce the enjoyment factor in my view.

What I have done so far and my personal impressions:

1st upgrade: Tighten every nut/bolt/screw I could find over, under and in the car!!

Result: So many less rattles! That for starters makes the car feel like it's shaking less!!!

2nd upgrade: Stock style suspension - Monroe Sensa-Trac shocks, Kings standard height springs, FCM bumpstops, NA Top mounts. Standard NA sway bars, bushes etc.

Result: Over the stuffed setup the car came with when I bought it, this setup feels great (for me and what I want). Supple over 99% of bumps or pot holes. The slightly stiffer springs are handled fine by these shocks. Comfortable ride with sufficiently competent handling for my purposes. Some change to body shake/vibrations due to the improved suspension soaking up the bumps a lot better.

3rd upgrade: A cheap ebay Strut Brace.

Result: A very, very slight, but noticeable change in stiffness. Looks nice when opens bonnet.

4th upgrade: Brown Davis Roll Bar.

Results: Massive difference, not all good. Made car feel more solid. Less rattles. But ... felt like hit bumps harder. Now had a different type of vibration over bumps that I hadn't felt before.

Tried a test: Tried tightening the strut brace. Made quite a difference, noticeable reduction in the new vibration, but still there.

5th upgrade: Thompson Products front lower chassis brace.

Result: Big change to vibrations. Actually found this upgrade felt better after I backed off the strut brace to original setting. The Thompson Brace has taken away a fair degree of the strange vibration that the roll bar introduced.

Results of all these modifications all together - For not much cost or effort, it's a completely different car! The combination of new, properly working suspension components, roll bar and chassis bracing does make a discernible difference, though still not complete. I still have some resonance/vibration over bumps, though pretty negligeable after these mods, so I have also been looking at the rear lower braces and will probably fit one at some stage. I like the FM rear lower brace as my exhaust is difficult to remove/replace and there are a lot of very positive reviews on it, but I may just try one of the cheap MX5 Mania rear braces first.

When I can afford it, I might even make the change to Koni's/Bilsteins with these Kings and maybe change the front sway bar, but although I'm always looking at various setups - more for the heck of it than any other reason - I'm in no hurry to alter what I now have.

I am happy.

[zephyrus17]

I got the FM Butterfly Brace and put it on my 90NA6, I could tell the difference the moment I sat in the seat. It just sagged less and going over bumps made it feel so much tighter as a unit. I'd highly recommend that

[sailaholic]

I got the FM Butterfly Brace and put it on my 90NA6, I could tell the difference the moment I sat in the seat. It just sagged less

There is no way it could have had that effect. For that to be apparent it would mean the whole passenger tub was flexing by pushing towards the ground (ie bending in the horizontal plane) while placing a meer 100kg? Distributed, load inside the supports (4 wheels) and almost outside the braced portion.

If one person made that much difference imagine how much flex a full tank of fuel, 2 people and a boot full of luggage would do! It would look like a dashhound who'd been fed way to much.

Sent from my GT-I9100 using Tapatalk 2

[NitroDann]

In response to sailaholic, I definately believe that bolt on braces can work, and I understand that it works on clamping force just like wheel alignment bolts do.

However a huge majority of aftermarket and factory braces have real flaws which make them questionable at best, such as the factory rear brace which is an extremely low quality unit in all facets, I mean the damn thing comes pre buckled!

Things like 3 point strut braces are BS, the 3rd point is the firewall, a member which can be flexed a whole centimeter if pushed with a single finger. Most strut braces you can wiggle with your hand.

Its not that braces do not work, or can not work, but the short version is that if its got buckles, bolts onto weak points, or bolts onto other points which flex the same direction as the first point, how can it possibly make an appreciable difference to the total stiffness of the chassis.

Dann

[Lokiel]

:
Things like 3 point strut braces are BS, the 3rd point is the firewall, a member which can be flexed a whole centimeter if pushed with a single finger.
:
Dann

Not many people know this, especially those who've never seen one installed, but there is a rear firewall brace that goes with the 3-point front strut brace which minimises firewall flex:




It would be more effective if those 3 screws at the base of the rear brace were actually bolted into something rather than simply drilled and screwed in but it does the job of preventing the firewall from flexing at the strut mount point.

[NitroDann]

Thats the first 3 point Ive seen with that extra brace.

Cool.

Dann

[Lokiel]

The Carbing and MAZDASPEED 3-point braces all come new with this rear bracket - unfortunately many 2nd hand ones I've seen for sale do not.

[olboy]

I think the 3 point brace is probably not all that silly
the firewall flexes forward and back but it is fairly strong sideways and would help to stop the top of the spring area from moving sideways, not that that matters much anyway !

[ja9]

I do believe in bracing and in my opinion they work. I to was interested in the FM rails and butterfly brace but find it too expensive here in Aus. I was reading on another forum that someone recommended you drill holes and inject polyurethane into the chassis rails. After the mixture sets it would be as good as the frame rails and I'm guessing not as heavy and no clearance issues.

What does the collective have to say about this?

[sailaholic]

Are you sure it would way less? I can't be bothered measuring the stock rails, but if you get me dimensions ill tell you if it weighs less.

I highly doubt it would stiffer. A) polyurethane is inherently not stiff (not on the same scale as steel) urethane is between 69 and 690 MPa. I doubt the squeeze in a tube stuff would be right on The stiff end.

Steel is 210 000 MPa. (see what I mean about not on the same scale)

B) while it has volume to help it most of the volume and weight is towards core of the shape that has limited effect. Certainly would not make up for the huge difference in stiffness.

Sent from my GT-I9100 using Tapatalk 2

[NitroDann]

Stiff expandafoam works, it doesnt work due to its inherant stiffness it helps in the same way allumalite works, by sandwiching a light material between 2 super stiff yet thin materials.

Dann

[sailaholic]

But..... Your not adding super stiff thin material, just bulk in the middle.

Sent from my GT-I9100 using Tapatalk 2