front strut brace for a V6 156

[cc]

Hi all
Does anyone know of an australian supplier as per the brace in the pic below.

Between the front suspension top mounts to the body.
cheers

ps a guy selling a GTA in victoria mentioned his was made by momo

[warsch]

The one on your picture has Ultra Racing sticker on it, so I assume that's the one.

They have a dealer in Aus or you can get their products off eBay. I've got three of their braces (just not like the one pictured) and they are good quality and fit perfectly.


I also recall Momo indeed having made a similar one. And there's also a couple of other designs.

[poohbah]

A previous owner imported Wiechers strut bars (front and rear) and a wishbone strut for my GTA direct from Germany
from a company named Squadra Sportiva which specialises in Alfa, Maserati, Fiat, Ferrari etc. The PO also used them to import Eibach anti-roll bar kit and the 330mm Brembos on my car.

But that was in 2010 - total cost way back then was only Euro220, including shipping. No idea what shipping might cost in today's crazy world, but the supplier is still going.

You can check out their Alfa stuff here:  https://shop.alfisti.net/, and sport suspension in particular here: https://shop.alfisti.net/Tuning-Styling/Alfa-156/Sports-Suspensions:::1_15_16.html

[cc]

are they are a worthwhile piece of gear to install?
Any recommendations?

[johnl]

Maybe, but probably not particularly worthwhile (but it can't hurt). It depends on the architecture of the 'strut' towers, mostly on how far forward of the firewall the towers are located. This type of 'strut' brace acts to prevent the tops of the two 'strut' towers moving closer together or farther apart when heavy loads are imparted into the towers (as the springs and dampers compress and decompress with suspension movements).

With many unibody chassis the tops of the 'strut towers' are located some distance forward of the firewall (often the case, but typically less so with more modern chassis). The longitudinal connection between the top of each tower and the firewall can be of a significant length, and may well lack lateral 'depth'. This means the metal structure between the firewall and the tower can lack lateral rigidity and so may flex sideways as load is imparted into the tower, allowing the tops of both towers to move a little closer together or farther apart. This affects the torsional  rigidity of the chassis as a whole, and has a minor destabilising affect on suspension geometries.

With such a chassis, if each (somewhat flexible) tower is laterally braced to the other tower by means of a 'strut brace' then each tower will be reinforced by the other tower, and so both towers will become more laterally stable. There will still be at least some lateral movement because neither tower is 100% laterally rigid and so despite being linked both towers can still move in unison (just less so than if unbraced to each other). But, if a secondary bracing tube were added that triangulated from at least one tower to somewhere on the firewall then nearly all lateral tower deflection will be near eliminated.

Note that the firewall is hugely resistant to lateral flexure, which is why triangulating the towers to it is a good thing (and some chassis designs do this without using a tower to tower brace). But whether a secondary bracing tube is used or not, a tower brace may add quite significant rigidity to this kind of chassis design and be a worthwhile fitment, eg. I added a simple robust home made strut brace to my old CB7 Accord, and subjectively could feel an improvement (not a huge one, but a noticable 'sharpening' of steering response).

However, with many unibody chassis (typically relatively newer designs rather than relatively more ancient ones) the strut towers are located far closer to the firewall, or are even effectively integrated into the firewall structure. With such a design feature there is inherently far less lateral tower deflection because the towers are already robustly braced by the firewall. With such a design, adding a tower brace will most probably add very little rigidity (but it can't hurt).

The 147, 156, GT chassis is of this second type. The 'strut' towers are located directly adjacent to the firewall and are braced to it with welded in triangulating plates, so this is not really a weak point in the chassis. Ages ago I added a simple robust home made tower brace to my 147, and subjectively I didn't feel any improvement...

Regards,
John.

[johnl]

Note too that some tower braces are poorly designed, and so lack the compressive / tensile rigidity that such a brace requires to be at all effective. 

An effective tower brace should ideally be straight with no bends. Any bend weakens a bracing tube in both compression and in tension (the brace will be more prone to significant flex at the location of the bend). If a bend is unavoidable (due to other components preventing the use of a straight tube), then to maintain rigidity the OD and / or wall thickness of the tube must increase substantially (ideally both).

Any brackets (that attach the brace tube to the towers) must well designed and robust. Quite a few strut braces that I've seen (actually seen or seen detail photos of) use brackets made from very thin steel and / or have poorly designed load paths within the bracket. Such brackets will flex under load, rendering the tower brace more or less ineffective, no matter how robust the brace tube itself may be.

I suspect this may be at least one reason why some people report that fitting a tower brace noticably improved their steering and / or handling, but other people report no difference after fitting a brace (to the same make / model of car, assuming it is a car that does respond to such a brace, and not all do). The suspicion is that person A may have fitted a good brace that actually works, while person B may have fitted a bad brace that looks cool but is actually useless. Of course the other explanations might be that person A may be experienceing a placebo affect, or that person B is insenstive to subtle steering and / or handling improvements...

Also, some manufacturers of these things claim an advantage over competitiors in their tower braces being fully welded into one integrated component, as opposed to being bolted together from seperate components (i.e. each end of the brace tube bolted to the mounting brackets). But note that this makes pretty much zero difference to whether a tower brace is effective or not. Tower braces only work in compression and tension. The brace tube may be exposed to some slight bending load, but regardless of whether it is 'fully welded' or bolted together it will have no significant strength in bend (it doesn't need to because this isn't how it works...). A well designed / made tower brace that is bolted together will work equally as well as a well designed / made brace that is 'fully welded'...

Regards,
John.

[GTVeloce]

A friend of mine has an NC MX5 which came with (I believe) a factory strut brace as per the image. It locates back to the firewall rather than over the top of the engine to the other side only.

[johnl]

I think Mazda has triangulated the towers to the firewall for very good reason (and very much doubt they would for no good reason...). This is a clear example of a chassis with 'strut towers' that are located some distance forward of the firewall, and would be less laterally constrained as a result. The triangulating brace tubes would be better if they were not somewhat curved, but things do need to fit in the available space...

Adding a tower to tower brace would create further rigidity, but might be a squeeze between the top of the motor and the underside of the bonnet? On closer inspection, it looks that perhaps in order for a tower to tower brace to pass over the top of the engine, the tube would need to be substantially curved (?). If so this would impair the rigidity of the brace, so at least partially defeating the purpose of it...

If the towers were located directly adjacent to or were in effect part of the firewall, then I doubt there would be any need for either a tower to tower brace, or for the stock firewall triangulating brace tubes.

Regards,
John.

[cc]

hadnt considered the adjacency of the strut towers to the firewall for the 156, they are quite close.
Might wait a while for members to comment before spending the a Lira.

[bazzbazz]

As John has mentioned, the strut towers on your 156 are already well braced by the firewall, and unless you intend taking to the racetrack and going 10/10ths at it, I think any effect you would notice in road going use would be more of a placebo.

I recon you'd be better off spending the money on taking your wife out somewhere nice for dinner and making her feel special. (well at least more special than the Alfa). You just know those brownie points are going to come in useful next time you really need to spend money on the Alfa.

[Colin Edwards]

One simple way of determining if front (or rear!) strut braces are needed is to string cotton thread between where a brace would be installed. 
See attached factory brace arrangement on the 124 Abarth Spider (Mazda MX5 ND!)
One end of the cotton thread would be clamped under a top strut mount nut.  The other end of the thread stuck to the firewall with Blu Tack or clear tape.  Whatever used, the cotton thread needs to be as tight as possible and no longer than is necessary.  Mark the cotton tread with liquid paper on either side of the Blu Tack or tape.
Drive the car in a manner and at a location (ideally a race track) where you believe a strut brace may have an impact. 
Have a look at the cotton - noting if it has pulled away from the Blu Tack / Tape.  If so, this means the distance between the fire wall and strut tower has increased for whatever reason. 
The test will likely need repeating a number of times before you get a reliable understanding of what's going on.  Also need to do both left and right suspension towers. 
Can be done with lasers - but a bit more costly!

[johnl]

Yes, the thread method has its' uses.

But in this case, what if the thread won't pass over the top of the engine without touching it or some part of it? This at least looks probable with the Fiat and Mazda engines in this 'Fiazda' chassis (judging only from the supplied photos). If so, then any engine movement would be likely to place at least some tension into the thread, and so the thread may slip at the 'Blu Tack' end (or whatever is loosely holding the thread). This could easily create the impression that one or both of the towers had flexed significantly, when neither may have done so...

The thread method works for checking whether an unbraced structure may significantly flex in a manner that would place the thread 'gauge' into tension. But, what if the nature of the flexure only imparted a compressive load into the thread? In testing the thread would just sag momentarily before resuming it's original position and 'length', leaving no 'tell tale' thread relocation...

Regards,
John.