Speed Series 2013 - Regs now out

[graham frankland]

Hi folks

Any one know the whereabouts of a Narrow Body Roll Cage at a reasonable price?

Thanks

Graham

[pete g]

you dont need one of them :d

[Mid life crisis]

Try the external links tab, one on there for a tenner

[davidgh]

Here is a clue David

Simon Westwood told me they reckoned that the fullscreen cars were about 10 mph slower in top speed than the aero screen cars, for a given spec.

My point exactly, Steve. The number of people on this forum who "reckon" is large; the number who produce evidence is limited.

[Captain Colonial]

My point exactly, Steve. The number of people on this forum who "reckon" is large; the number who produce evidence is limited.

New keyboard please

[XTR2Turbo]

My point exactly, Steve. The number of people on this forum who "reckon" is large; the number who produce evidence is limited.

New keyboard please

evidence please

[Mid life crisis]

Apples with apples I believe you removed the weight and drag of your screen and then replaced it with the drag and weight of a full cage "Martin H's post" No wonder you found no differance in performance

Think I will go with the factories advice

[Kevin Jones]

But weight plays no part in top speed, only how quick you get to it.

Playing with numbers, a 0.3m2 increase in frontal areas looks like it would be enough to lop 10mph off a 200bhp car. You would not notice this at all up to 60mph but to 100mph you should be ~0.5s quicker/slower because of it. Got any datalogs David?

[stephenh]

My point exactly, Steve. The number of people on this forum who "reckon" is large; the number who produce evidence is limited.

I agree David, but I'd expect the factory to have an idea of how fast their cars go? Maybe you don't realise who I was quoting? Simon is (and has been for many years) the sales manager at the Westfield factory. It cropped up in conversation when we were discussing the specification of the car they were going to build for me nearly 5 years ago. I asked Simon what advantage/disadvantage an aeroscreen would be compared to a full screen. So it is an "informed" opinion which I was quoting!! :d

[Howard]

The drag on a cage could well be significant. Has anyone tried streamlining the tubing? Not altering the tubing itself of course, but with some nice carbon fibre add-ons. Could be a marketing opportunity.

I predict a conversation with Mick.

Remember where you saw it first...

[RobC]

Although the added rigidity if a cage may well out way the negative drag effects...

as said horse for courses...

carbon streamlining of a cage... awesome

[funky munky]

Thanks guys, was factoring extra weight of diffuser into diet regime, figured salad meals for a fortnight would be sufficient ? Wonder if Santa is visiting Plays-kool ? I have Harnesses on order from luke (top guy)

[Terry Everall]

IMHO cages do add weight and DRAG

[funky munky]

Kevin,

This has got me thinking

interesting info, feel free to comment, but here is an assumption. My car has much less than 200bhp but factor in Gurston Down Hillclimb this year my speed at the bottom of the hill and through the finish was 85mph ( yes I know thats not quick enough having seen Paul and Stuart there) so assuming I am at 60mph at each half way point of each section that could well be 0.5 of a second lost due to drag of having a Windscreen ?

I appreciate its difficult on a like for like, but two cars with same power/gearing/grip etc experiance of driver and the only difference is one has a windscreen and one has an aero, the aero could be 0.5 quicker over a given hill ?

[MartinH]

But weight plays no part in top speed, only how quick you get to it.

Playing with numbers, a 0.3m2 increase in frontal areas looks like it would be enough to lop 10mph off a 200bhp car. You would not notice this at all up to 60mph but to 100mph you should be ~0.5s quicker/slower because of it. Got any datalogs David?

And remember double the Velocity and the Drag increases by four fold

Edited to say: there is evidence to support the above statement (might have been by Mr Newton or one of that breed)