dan__wright
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posted on 4/3/07 at 08:38 PM |
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7 Aerodynamics? rear down force?
been thinking lots,
does any one suffer from lack of down force in a 7 replica? anyone fitted some kind of spoiler to get down force over the rear wheels? maybe a lip
spoiler along the lines of the old TT?
Discuss...
Dan
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RichardK
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posted on 4/3/07 at 08:41 PM |
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Reckon the weight of my arse will suffice
Rich
Gallery updated 11/01/2011
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Avoneer
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posted on 4/3/07 at 09:01 PM |
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It wouldn't be a 7 with a spoiler on the back - it would look pants.
Pat...
No trees were killed in the sending of this message.
However a large number of electrons were terribly inconvenienced.
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Kev99
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posted on 4/3/07 at 09:03 PM |
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That part of the fun
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mookaloid
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posted on 4/3/07 at 09:07 PM |
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I have seen quite a few 7's with diffusers under the rear - some say that these help
"That thing you're thinking - it wont be that."
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SixedUp
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posted on 4/3/07 at 09:16 PM |
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Let's be honest. Sevens have all the aerodynamics of a brick outhouse. Apart from removing the windscreen, I don't think there's
much else you can do without completely changing the look of the car ... in which case, why not make something else?
Cheers
Richard
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mistergrumpy
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posted on 4/3/07 at 09:19 PM |
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The Donkervoort that they used on the Nurburgring had hard top and rear spoiler and looks great I reckon.
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PAUL FISHER
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posted on 4/3/07 at 09:21 PM |
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Like this
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chriscook
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posted on 4/3/07 at 09:22 PM |
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You'd be better off doing all you can to reduce the front lift first..
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PAUL FISHER
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posted on 4/3/07 at 09:23 PM |
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And
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dan__wright
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posted on 4/3/07 at 09:36 PM |
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i was thinking something a little like this on the edge of the 'boot'
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locoR1
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posted on 4/3/07 at 09:38 PM |
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Spotted a 7 with one of the huge great carbonfiber spoilers Halfords sell attached to the back of it last summer should of taken a picture!
I nearly wet myself
Dave.............
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locoR1
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posted on 4/3/07 at 09:43 PM |
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That looks quite nice! A nice small one along the top of the back panel could look good if done well!
Ad a center brake light an bobs ur uncle
Dave...
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TangoMan
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posted on 4/3/07 at 09:45 PM |
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If mine is anything to go by, downforce is nothing more than a wet dream.
While making a boot panel cover last year I used veclo to fasten it as a temporary measure. Over 70 and the panel lifted up and tore of its hinges.
I think it is safe to say that with a screen fitted there is lots of aerodymanic lift at the rear.
Summer's here!!!!
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Liam
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posted on 4/3/07 at 11:09 PM |
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quote: Originally posted by dan__wright
i was thinking something a little like this on the edge of the 'boot'
With that slab of a front windscreen, the open cabin, and the really short distance to the back of the 'boot' I very much doubt
you'd get any useful airflow over a lip spoiler like that on a 7. I doubt it does a great deal on the convertible TT to be honest. You'd
need something up out of the turbulent air flow over the cabin to do anything on a 7.
Liam
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RazMan
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posted on 5/3/07 at 08:16 AM |
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A small lip like that can only be regarded as purely cosmetic on a Seven as it will have no aero effect whatsoever.
As already said, they have the aerodynamic qualities of a brick. The main point of the design is for pure enjoyment at sub 100mph speeds. Anyway, aero
mods only make a real difference at speeds approaching 200mph and not many Sevens will achieve that without disintegrating
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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britishtrident
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posted on 5/3/07 at 08:17 AM |
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A Duttonesque spoiler ugh !!!! see http://www.madabout-kitcars.com/images/imgtxt/700/1172057836-dut3.jpg
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Phil.J
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posted on 5/3/07 at 08:49 AM |
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As has been said, these cars have the aerodynamics of a brick. I think the best bet is to build in a propper under-car air management system which
could be made to give realistic and useful downforce without too much extra drag.
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smart51
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posted on 5/3/07 at 09:01 AM |
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quote: Originally posted by RazMan
A small lip like that can only be regarded as purely cosmetic on a Seven as it will have no aero effect whatsoever.
This is an often quoted cliche (several times in this thread) but that doesn’t make it true. The seven has very high drag, due largely to exposed
wheel arches front and rear, open cockpit and vertical windscreen. This does not mean that you cannot improve it at all. A well designed lip spoiler
will reduce lift at the rear no matter how much drag the front wheels create. The little Audi TT spoiler has a lot of effect if you remember back to
their early handling problems.
Sure, you’re never going to change the seven into a Honda Insight in terms of drag but little things here and there can and do affect aero dynamics in
their own way. Here are some examples:
Caterham made front wings for one of its cars with little spoilers on the rear. They reduced lift at the front by a noticeable amount. I’m told that
the further round your wings go the better for this too.
Rigid half doors have been shown to reduce drag, as has a tonnau cover for the passenger side of the car (with no windscreen)
Aerodynamics don’t just affect behaviour above 100 MPH. It has an affect at road speeds too. The effect is related to the cube of speed, so the
affect at 100 MPH is 8 times the effect at 50, but have you ever don’t 100 MPH in your car? I’ve been on 2 track days in mine.
So go ahead. Try a discreet spoiler, but do a bit of research to find the optimum angle and size for what you’re trying to achieve. You may be able
to improve your car a bit without making it look stupid.
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02GF74
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posted on 5/3/07 at 09:22 AM |
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re: the ickle lipe spoilers; from what I have read, they don't reate down force per se but help smooth out the airflow over the back to some
good effect - how mcuh that helps over no spoiler I don't know.
dpoesn't downforce and spoilers give significant effect at speeds that are more then most 7s are capable of?
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RazMan
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posted on 5/3/07 at 09:39 AM |
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Indeed you can make some changes by fully enclosing the front wheels, reducing the rake of the windscreen, fitting a front spoiler, panelling out the
underside, fitting a diffuser etc etc. My point was that a small lip on the back of such a non-slippery shape as a 'standard' Seven will
make little or no difference. By the time the air has reached the spoiler, it will be so turbulent that there will be no benefit at all.
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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TimC
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posted on 5/3/07 at 09:43 AM |
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WSCC Speed Series Champion:
[Edited on 5/3/07 by TimC]
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red22
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posted on 5/3/07 at 09:44 AM |
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"Anyway, aero mods only make a real difference at speeds approaching 200mph and not many Sevens will achieve that without disintegrating
"
My thoughts to this and similar points of view are to think of early aeroplanes these flew at speeds less than 100mph and without dought thet flew. So
if these early planes wings could generate lift then inverted they will certainly generate downforce.
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Tralfaz
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posted on 5/3/07 at 01:02 PM |
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You could fully pan the bottom and go this route..
Description
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iank
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posted on 5/3/07 at 01:13 PM |
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quote: Originally posted by RazMan
A small lip like that can only be regarded as purely cosmetic on a Seven as it will have no aero effect whatsoever.
As already said, they have the aerodynamic qualities of a brick. The main point of the design is for pure enjoyment at sub 100mph speeds. Anyway, aero
mods only make a real difference at speeds approaching 200mph and not many Sevens will achieve that without disintegrating
Agree about the lip spoiler, but I think you'll find aero comes into play much sooner than 200mph - otherwise hill climbers wouldn't use
wings. Or are you talking exclusively about 7's?
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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