silhouettes

[Ian Podmore]

I seem to remember reading that filters were allowed external to the sillouette, but if the filter were removed there should be nothing protruding the bonnet line   Not that's of any interest to me on my car !

[Blatman]

Unless you're being scruted by Mr Beardy at llandow (I think it was...)

Look out. Can opener.....

[Mark Stanton]

Leave it            

[SteveD]

thought they would of shot the bearded one by now    god he's an A*** !

[prelit]

Guys

I have spoken today to a 'championship co-ordinator' with respect to the silhouette rules and he believes that we may well be breaking the 'road going' regs by running diffusers and front air dams even if they are below axle centre line.

A quick thumb of the 04 blue book states that the silhouette for 'Roadgoing Specialist Production Cars' must remain unaltered (no mention of axle centre line so I take it that this also must mean both plan & side views)

As I compete in class 2b (roadgoing), I really need to know if my car falls into this above class.

However in the regs for 'Modified Production Cars' (which I'm guessing must be non road going) it clearly states the silhouette in side elevation only needs to remain above the wheel centre line thus making these diffuser and air dams legal.

The 'diffuser' on my pre-lit car is a simple alloy sheet to seal the fuel tank area with 4 vertical alloy fences pop riveted on.

This was made before the car was even sprinted and was/is just a fashion statement. I don't believe in any way it adds to the cars performance, in fact I've been thinking of removing it anyway to save a little weight but unfortuately it has made an ideal place to mount the fuel pump and filter.  

Hopefully I'm reading the Blue Book wrong, but I almost asigned myself to removing the vertical fences this weekend just to be sure I'm not contravening any rules or any grey areas for that matter.

Help needed please

Cheers,

pre-lit

[Mark Stanton]

'Modified Production Cars

Westfields are not seen as falling into this class.

Thing is you've hit the nail on the head with

just a fashion statement. I don't believe in any way it adds to the cars performance, in fact I've been thinking of removing it anyway to save a little weight but unfortuately it has made an ideal place to mount the fuel pump and filter.

To have any proper and fully effective aerodynamic effect they should really be mounted far less than 100mm above ground level       Which would then directly contravene Blue Book Rulings - without any "grey areas" of different interpretations

All these air dams and diffusers make very little difference to times put in by drivers but simply "wind-up" your fellow championship competitor - IMHO I think this was proved recently when Ash was made to remove his diffuser at Shelsley and drove a quicker time without it    

With regard to the WSCC Championship - we've been quite open about allowing these items as cars fitted with them are often beaten by cars without        

Other championships however may have different views as they perhaps do not attract as many Westfields and as such are not so specifically involved      

[Arm]

Midland Speed Organisers were very clear on this after discussing again at the last event.

If the rear diffuser changes the silhouette then it is not allowed.

I have a cut down diffuser and this does not project rearward and does not change the silhouette; it was deemed acceptable.

A rear diffuser in my opinion reduces the turbulance around the rear of the car at speeds of 100mph or over. If we are running at these speeds then I feel it is a gain.

Although I went quicker at Shelsley without it was a suprise and the car was more unstable than on the earlier runs.

I dont mind now its been made crystal clear. So I can run the big diffuser at a WSCC round, the small diffuser at a Midland round or no diffuser at a slower circuit.

Ash

[prelit]

Thanks Mark & Ash,

but I'm still unsure !!!!!!

Are we saying that these air dams & diffuser's such as mine with vertical fences are OK for the Westfield speed series but not OK for normal speed events? (roadgoing classes)

Ash, has your cut down version got any vertical planes?

Cheers

Pre-lit

[Mark Stanton]

Ash

Are you saying you are using a large diffuser which extends way past the rear bodywork line - bit like the ones Adrian and Derek use in mod class - that for sure can be interpretated as changing silohouette and not allowed in road going class           

If you use the smaller verison then that is far more acceptable for road-going class car        

Perhaps in hindsight - we need further clarification in future WSCC regs          

100mph or over - I wish

I have a cut down diffuser and this does not project rearward and does not change the silhouette

So does that mean you are accepting the large one does change silohouette          

[Arm]

The cut down diffusor as viewed at a Midland event on Sunday is still visible from the side of the car thanks to its vertical sides, however as it did not stick rearward of the body it was considered acceptable. Makes it appear more like the std fit rear apron from side elevation. Thats possibly why its acceptable.

Thats the greyness to all this because my arguement in favour of the larger diffuser (hanging out the back of the body) was it was no further rearward than the spare wheel and carrier / numberplate. And so the confusion is with the limited descriptions in the blue book and club regs.

So there are still big diffusers out there and they have been in use for many years on roadgoing sprint cars so why change ?

Prelit - yes it has vertical planes. If removing it slows you down then please comply  

[prelit]

Midland Speed Organisers were very clear on this after discussing again at the last event.

If the rear diffuser changes the silhouette then it is not allowed.

Ash,

I guess this must include those 'trick' air dams as well.

Thankfully I don't run one of these !!!! although I was in the process of fabricating one. b******* !

Looks like I will be removing the vertical fences and just

keeping the flat sheet.

Pre-lit

[westy]

Perhaps in hindsight - we need further clarification in future WSCC regs          

I'll carry on as usual then