Best chissis bracing configation

[Lokiel]

I think it was the first SE.
Which makes sense.

What additional bracing did it have, it hard to quantify anything with a list but for interest.

Dann

The SE has a few additional braces than stock NBs but mine also had the MX5 Plus Twin hoop rollbar, FM frame rails, Boss Frog Frog Arms and Carbing 3-point strut brace.
Aside from door braces/bars, seam welding or a cage, I think that's as stiff as you can get and when on 4 stands, if they're not finely adjustable and your floor is not flat, the car will pivot on the tallest diagonal stands.

[Magpie]

Dann did organise a group buy of 'Frog arms' that changes the resonant frequency that the chassis vibrates at due to changes in mass and damping in the flexibility by bolting on heavy components . However clarified this with "This is a noticeable change but claiming that its actually noticeably stiffer AND that its a performance improvement is just silly"

However the above conflicts with the 'sell' words used in the group buy... http://mx5cartalk.com/forum/viewtopic.php?p=795046#p795046

The forum has been subject to many debates about what stiffening does and doesnt do and what work and doesnt work.

General consensus is that well designed and substantially strong frame rails, door bars and fender braces (frog arms) work well to increase stiffness. The definite benefit is reduced noise vibration and harshness (NVH) and arguable benefits include increased predictability due to providing the suspension a stronger stiffer platform to work from.

Frog arms stiffen the front end from the firewall to the suspension tower tops to help reduce twisting over bumps and hard cornering. They help to triangulate the front frame rails and bolt to very substantial parts of the car.

Dann

[lizard]

reminds me of a snake oil salesman

[NitroDann]

I have said nothing contradictory and stand by evertthing I have written in both threads and contexts.

Dann

[Danny]

There's a simple test to confirm if the roll bar adds stiffness.

Open both doors and pinpoint, on masking tape if you don't want to scribble on the paint, two measure points where the A and B pillars would be. Jack the car up near one wheel and measure the gap. Now loosen the bar bolts and do another measurement. Any difference would indicate the bar is adding stiffness.

The butterfly brace, as on the SE, would be good to test this way too. It should show a more significant difference.

Don't disturb the jack or get in the car once it's lifted or the result could be corrupted.

[irwin83r]

Driving a nb8a with no additional bracing other than a tower brace (bring bring)
And then driving a nb8b with the additional factory bracing ( im guessing the engineers at Mazda decided was worth while.. And I agree) plus a carbing front and rear tower brace, frog arms and I think a rear cradle brace.
Both cars running tein mono flex, both cars running kumho semi slicks both cars running upgraded sway bars.
I can 100% vouch the car with more bracing is easier to drive, more predictable and the progression to over steer smoother.
I can also however vouch that these two cars were within hundredths of each other on any given day.
There are variables between the cars that could arguably gain a little more here or there.. Abs, vvt, ECU's but when you look at track times and see cars lapping that close routinely I think it's safe to say.. You learn to piss with the c#@k youve got.

That all being said. I have now purchased frog arms, butterfly brace and a rear cradle brace. Why you ask? I was getting the same results you say?
Because its easier to drive the nb8b at ten tenths for 60+ laps during theWakefield 300.

Had my time again I would buy some under body bracing along with the rest of my suspension for club level racing. Under body only. Lowest centre of gravity.. Minimal weight gain.. and the lightest cams approved half cage.
Once you get serious and get a full cage you would be silly not to get bracing fabricated between the suspension components under the body. Also putting the car on a chassis jig getting it all square.. Making the car chassis tunable and above all easy to drive is going to make you lap more consistently under pressure, not wrestling a wild animal around the track.. Both might be capable of the same lap times, same grip, same power. But one will let you play chess while you drive while the other will need every bit of brain power to stay on the black stuff.. (Some Exaggeration)

[lightyear]

When I drove the NB8B with the same suspension, tyres wheels and all the associated braces they come with. I found the car to be an over steering bucket to drive. Put all the same running gear in a "floppy" NA6 shell with no bracing what so ever. Much better to drive. My current NB8B has not one brace factory or otherwise. Until you have excessively grippy tyres, I don't think it's necessary to add weight to the chassis in the form of braces. Braces won't make you faster in a straight line, and will only help a small percent if any at a given point around a corner.
I vote for no braces, and put the money towards something like better tyres. I bet any money, you will go faster. Tyres>braces.....

[rascal]

But didnt that 'floppy' NA6 shell have a whopping big front spoiler and very little rear aero? suggesting that the aero imbalance may have been countered by the chassis flex? My NB8A with some braces(which would be stiffer than a no brace NA6) is an oversteering bucket when running front splitter and no rear aero, but back to neutral when front and back aero matched.
I'd also suggest that R spec tyres would be sufficiently grippy enough to see gains from a stiffer chassis.

I do agree with you that tyres>braces but I think then tyres+braces>tyres
Guess we need someone to run with all the braces and log their laps, and then run without the braces and log the laps and see the difference to really know if they help or hinder..