The black plastic thingy mystery

[Cav]

Can anyone enlighten me on what this black plastic thingy does?

My guess is that it stabilises the AU at speed.

[aussiblue]

Bumper apron or valance. As they say at: https://www.carid.com/articles/what-...r-valance.html

In some cases, valance panels don't enhance aerodynamics at all. They might be simple cover pieces that conceal areas below the level of the bumper (or bumper cover) that would otherwise be exposed. In the front, this would effectively cover and protect the lower part of the radiator. more details on - https://www.carid.com/articles/what-...r-valance.html

I think the bolded bit is mostly what it does although the air flow might be untidier without it.

[Peter B - CV8]

Is that on the trailing edge of the wheel arch ??? If so, it's probably just a glorified rain/dust spat that utilises the disrupted air flow to keep crap away from the side of the car.

[Cav]

I assumed from the pic I posted that it would be clear as to where on the AU the 'thingy' is located.

These are on the front mudguards.

[Cav]

I think these are better pics to show their size and location on the front mudguards

[aussiblue]

I assumed from the pic I posted that it would be clear as to where on the AU the 'thingy' is located.

These are on the front mudguards.

Sorry no I though it was a pic under the front. OK spats to stop mud and dirt covering the bodywork to rear of wheels. Edit: Ok sen the new pis; those spats are aerodynamic; see https://www.youtube.com/watch?v=TCzfWgPKbbQ for how they work generally.

[Raptor]

Hardly a mystery, unless you live under a rock or are a flat-earther or something

They are to satisfy ADR requirements wrt wheel coverage (as you well know).

Also found on many imports, until discerning owners rip the ugly things off

Why they would be required on an AU Falcon/Fairmont/Fairlane etc (solely designed for the domestic market) makes you wonder if the designers had ever consulted the local regulations

AU's




.

[aussiblue]

But they are also still there to keep the bodywork clean especially if they are aftermarket rather than factory e.g. https://www.adamesh.co.uk/jaguar-x15...ats-4721-p.asp

[Cav]

Thanks Raptor but I have my doubts.

The hint is in the design - see how they are formed to slice through the air?

I did a search, but I came up empty. Maybe I missed something.

A comparison of airflow would settle it once and for all.

[superroo]

What Raptor said.
My memory says added on AU2 onward.
Still see them on many imports.

As to why my guess is late regulation change or unknown implementation.
With where they are it would knock into the guards and the front bumper to change. Too much tooling money when the small add on fixes it.

[Silver Ghia]

Originally Posted by superroo

What Raptor said.
My memory says added on AU2 onward.
Still see them on many imports.

As to why my guess is late regulation change or unknown implementation.
With where they are it would knock into the guards and the front bumper to change. Too much tooling money when the small add on fixes it.

My thoughts is because the wheels and tyres got larger with later variants of the AU, a styling trend that probably wasn't anticipated in the original design. My 1998 AU Fairmont wheels were only 15 inch which would have legally tucked into the guard.

[whitelion65]

Originally Posted by Cav

I assumed from the pic I posted that it would be clear as to where on the AU the 'thingy' is located.

These are on the front mudguards.

Sorry Cav,
I thought you'd left the lens cap in the way.....again ;-)

[Cav]

Originally Posted by whitelion65

Sorry Cav,
I thought you'd left the lens cap in the way.....again ;-)

[aussiblue]

Nah; their real secret purpose is to trap water between them and the guards to promote rust so you have to buy a new Falcon earlier than otherwise may have been the case.

[Tickford.]

Originally Posted by Raptor

They are to satisfy ADR requirements wrt wheel coverage (as you well know).

Raptor is 100% correct.

It was added to satisfy ADR regulations after a design oversight by FoMoCo Australia. You will find these "black plastic things" on ALL AU's (AU1, AU2 and AU3) fitted with the 17" (or 18") Tickford wheels and suspension (either optioned or standard fitment) and 235 wide tyres. Wasn't just a AU2/AU3 thing either. AU1 Tickford cars such as the XR's and T-Series had them. Even a AU1 Forte would have them if it was optioned up with 17" Tickford wheels and suspension.

The quick and simple explanation is, when the 17" or 18" wheels with 235 tyres were fitted to the AU, the front edge of the wheel and tyre were slightly visible from a direct top view, making the vehicle uncompliant to ADR's. A quick solution was designed and implemented by using these "plastic thingy's".

Wonder how many AU's that came factory fitted with 17"/18" wheels and 235 wide tyres still have them on? There would be many AU's out there that have had them come off, or removed by now. Making them non-compliant to ADR's.

Again, not a rain deflector, nothing to do with dust, aero, or slicing through the air, etc. The AU was a simple car. Please don't overcomplicate it.

edit: Read through this thread from the start.... oh boy....

[Cav]

So, are youse blokes saying that if the plastic thingies on 17 inch AUs (and above) are missing then it is a fail for roadworthy?

[Raptor]

Originally Posted by Cav

So, are youse blokes saying that if the plastic thingies on 17 inch AUs (and above) are missing then it is a fail for roadworthy?

Only if it's still at stock (4wd like) ride height and everything is in good original condition as per the LLBP brigade.

If like most old Falcons the front springs will have sagged, the balljoints are going and the bushes are stuffed. This fail safe will have the front end adopting some negative camber and the tops of the tyres should be tucked under the guards no probs



.

[Beastie]

It's a leaf deflector...

[Cav]

Originally Posted by Beastie

It's a leaf deflector...

I think I will leaf that comment alone.

[Cav]

Originally Posted by Raptor

Only if it's still at stock (4wd like) ride height and everything is in good original condition as per the LLBP brigade.

If like most old Falcons the front springs will have sagged, the balljoints are going and the bushes are stuffed. This fail safe will have the front end adopting some negative camber and the tops of the tyres should be tucked under the guards no probs
.

I think you are making it up.

Even if the top were tucked in as you say, what about the bottom?

Surely as you say the 'black thingy' is to meet design rules, then the bottom of the tyre will still protrude as much as it ever did.

I think you have a closed mind on this Raptor and are unwilling to look at credible alternatives such as wind deflection.

If what you profess, that the 'black thingy' is needed to meet Australian design rules, then those AUs with 17 inch or larger wheels must be defective. No?

Except for the ones with stuffed suspension.

[GasoLane]

Could it be an aerodynamic design to help lift the front to compensate for overweight drivers?

[Beastie]

Originally Posted by GasOLane

Could it be an aerodynamic design to help lift the front to compensate for overweight drivers?

Good point, but in this case it would only need to be on the drivers side...

Was it an optional extra...

[Captain Stubing]

Perhaps it was a stiffener, to strengthen the guard for when portly gentlemen owners non-nonchalantly lean against it, while telling of how they managed to acquire their fine steed.

[Cav]

It certainly is a weighty issue folks.

[aussiblue]

I always thought black plastic thingies were always battery operated, rocket shaped and it was forbidden to ask what they were for.

[superroo]

Originally Posted by Cav

So, are youse blokes saying that if the plastic thingies on 17 inch AUs (and above) are missing then it is a fail for roadworthy?

No. Roadworthy check does not cover all area's of ADR's.
For roadworthy, my memory says top portion of tyre tread must be under guard from above. Hence stretched tyres are legal.

Best example is on exhausts. ADR has static & drive by noise levels.
Road worthy only cares about static test, hence can be louder.

[Cav]

Originally Posted by aussiblue

I always thought black plastic thingies were always battery operated, rocket shaped and it was forbidden to ask what they were for.

You're a naughty boy AB

[Cav]

Originally Posted by superroo

No. Roadworthy check does not cover all area's of ADR's.
For roadworthy, my memory says top portion of tyre tread must be under guard from above. Hence stretched tyres are legal.

Best example is on exhausts. ADR has static & drive by noise levels.
Road worthy only cares about static test, hence can be louder.

So no yellow canary from Mr Plod?

[superroo]

You're good.
Reading below there is some ambiguity in the roadworthy (VSI), but general consensus I'm aware of is when viewed from above

ADR 42

42.12.1.2.1.
The wheel guards must meet the following requirements when the wheels are in the straight ahead position:

42.12.1.2.1.1.
In the part formed by radial planes at an angle of 30 degrees to the front and 50 degrees to the rear of the centre of the wheel (see figure 1), the overall width (q) of the wheel guards must be at least sufficient to cover the tyre ‘section width’ (b) of the tyres fitted to the vehicle taking into account the extremes of tyre/wheel combination as specified by the ‘manufacturer’

42.12.1.2.1.3.1.
The projection - situated in the vertical plane of the tyre axis - of the depth (p) of the outer edge of the wheel guards, measured in the vertical longitudinal plane passing through the centre of the tyre, must be at least 30 mm. This depth (p) may be reduced progressively to zero at the radial planes specified in clause 42.12.1.2.1.1

Vic Roads VSI 8

..and, when in the straight ahead position, the guard or bodywork of the vehicle must cover the section width of the tyre
Note - The section width of a tyre is the distance between the outsides of the sidewalls of an inflated tyre excluding any markings, bands or ribs.

[Uncle_Ken]

Originally Posted by Uncle_Ken

Well I've been busy doing 'stuff' of late.
But I did buy a set of AU wheel arch for a UTE.
As they are currently reddish, I put one on BMC's AU to have a look.


.

.


UK

Au Utes had these as an option
UK