Dunc
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| posted on 12/2/02 at 12:04 PM |
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Aerodynamics & stuff.
I know there probably isn't much scope for this kind of discussion as far as locosts are concerned but have any of you guys thought about aerodynamic
stuff. I'm not talking about cossie wings on the back or deep mouth spoilers at the front, more about extending the side panels down an inch to
create a lip, totally flat underside and a tuneable venturis at the rear. I've not given it much thought and perhaps need to be talked out of it as
being a stupid idea.
Dunc.
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Metal Hippy™
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| posted on 12/2/02 at 04:12 PM |
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Damn, there was me gonna put a huge Porsche Whaletail on ours... 
President of the Non-conformist Locost Builders Club. E-mail for details...
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chrisg
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 posted on 12/2/02 at 06:57 PM |
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Hey up Dunc,
I think the"flat bottom" of a Locost would suit a Ground efect approach very well.
Look at the underside of a Jag XJ220, or a model of one (if you don't happen to have one)it's comletely flat but with venturis at the rear as you
say.
I think we need someone with a wind tunnel!!
Cheers
Chris
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Dunc
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| posted on 12/2/02 at 07:09 PM |
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funny you should mention the XJ220, I have the model and there's a cute metallic grey one sitting in my local jag garage, need to be shorter than me
to fit in it though. Actually once I've finished my locost I'm going to use my new found skills and build a xj220 or similar looking, might go down
the db7 route first, that way I'm guaranteed to fit and I can change the crappy rear lights.
Dunc.
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bob
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| posted on 12/2/02 at 07:15 PM |
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Lads
I'm not convinced,is this an early april fools.7s are as aerodynamic as a brick(or pacific F1 car,remember them)
I'm not sure there is much you can do with that windscreen,or are we all going to start laying down in our cars.
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Dunc
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| posted on 12/2/02 at 09:57 PM |
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I agree with the windscreen being as slick as an air brake but the car does have a fairly small frontal area, important for reduced drag, and it is
wedge shaped which will create a vacuum below the car if the side skirts are adequate and depending on where the venturis starts, can produce extra
downforce to either the front or rear of the car.
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bob
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| posted on 12/2/02 at 10:12 PM |
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Dunc
Yep i see where you are coming from now,i think i'll get the car legal and on the road first.
Driving the car as basic for a while would give me a better idea as to wether tweeking is actually beneficial.
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chrisg
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 posted on 12/2/02 at 10:54 PM |
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Well I'm having barge boards and slicks, and I've already got our lass outside in a helmet with a plastic petrol can and a wheelbrace!
Cheers
Chris
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bob
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| posted on 12/2/02 at 11:07 PM |
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Have you got a camcorder i'd like to see that
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chrisg
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| posted on 13/2/02 at 11:53 PM |
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No Bob,
the wife's just smashed it over my head
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philgregson
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| posted on 8/8/02 at 09:23 PM |
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Is this such a daft idea? - probably - but I've just been looking at the photo's of that german 7 type thing everyone got excited about some time
ago - There was definately what seemed to be a difuser underneath the paneled rear floor.
I'm not actually convinced about the concept myself (although I know only the basics about this) because there is not, on most peoples cars, a solid
panel underneath the engine bay and this would surely cause problems with the airfdlow farther back. Also - would a functional side skirt have to be
too low and be too vunerable to damage?
Probably a dead duck but if it could be used to stick the old horseless carriage to the road even better it could be interesting.
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Jon Ison
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| posted on 9/8/02 at 03:49 PM |
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well rear defuser is on my list of mods, cosmetic maybe....but duin it anyways....
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Marcus
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| posted on 9/8/02 at 05:09 PM |
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Was at a hillclimb at Harewood last year, there was this Westfield and it had one of these diffusers under the rear panel. He swore it made a hell of
a difference to the grip at high speeds, so much so that it understeered everywhere so he had to put a big front spoiler on aswell. Looked stupid went
like doggy doos off a spear and jackson!
Marcus
Because kits are for girls!!
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philgregson
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| posted on 11/8/02 at 03:13 PM |
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So maybe it does work - I'm not sure how though:
I would have thought that an aerodynamicaly styled car (not a locost) was esentially like a wing in that air traveling over the top has further to go
and therefore has reduced pressure above the car and not below as you would need for ground effect.
In fact any car has further to go over the top I suppose although the turbulance of the flow will have an effect of some sort.
Now when it comes to diffusers my first thought would have been that they slow the flow relative to the air going over the car still further.
Obviously none of this can be true or ground effect would not work - so for interests sake can anyone enlighten me.
P.S. re the recent discussion on splitters: aren't they connected with this somehow - splitting the flow under and over the car.
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Highcost builder
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| posted on 12/8/02 at 08:17 PM |
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I think im missing something here i thought the idea of ground effect came into force the faster you go combined with the lower you go, but if you do
sucessfully take a roundabout at 90 let me know i might give it some thought too.
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aph
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| posted on 14/8/02 at 02:27 PM |
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ground effects rely on the air rushing past ie the rear part of the car and pulling air from under neath the car hence pulling it down and creating
downforce. but the car needs to be very low and the air flow around exit of the venturi needs to be fast enough to do any thing. Good example of
ground effects/venturi is the old su carb.
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john_s
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| posted on 14/8/02 at 04:54 PM |
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I thought that the ground effect arose from tha car running lower at the front than the rear so that the air under the car is forced to expand and
reduces its pressure. The higher pressure air over the top of the car then presses the car down onto the road.
John.
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John Singleton
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semi42
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| posted on 14/8/02 at 05:37 PM |
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"I thought that the ground effect arose from tha car running lower at the front than the rear so that the air under the car is forced to expand and
reduces its pressure. The higher pressure air over the top of the car then presses the car down onto the road."
Nah..Its all to do with witchcraft and voodoo
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john_s
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| posted on 14/8/02 at 08:53 PM |
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quote:
Nah..Its all to do with witchcraft and voodoo
What about inverted skyhooks to pull it down?
John
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John Singleton
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johnston
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| posted on 15/8/02 at 08:01 PM |
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i've heard if you attach your inverted sky hooks with a couple of long weights (but u'll need a left handed screwdriver to screw them on) and keep
them warm with a bucket of stem while ur doin it' it will absoultly feck all 
p.s. now the end of summer is comin dont forget to fill all your old vw beetles and campers with anti-freeze
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