Rich
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
Reckon the weight of my arse will suffice
Rich
It wouldn't be a 7 with a spoiler on the back - it would look pants.
Pat...
That part of the fun
I have seen quite a few 7's with diffusers under the rear - some say that these help
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
The Donkervoort that they used on the Nurburgring had hard top and rear spoiler and looks great I reckon.
Like this.jpg)
You'd be better off doing all you can to reduce the front lift first..
And.jpg)
i was thinking something a little like this on the edge of the 'boot'
.jpg)
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.............
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...
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.
quote:
Originally posted by dan__wright
i was thinking something a little like this on the edge of the 'boot'
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
A Duttonesque spoiler ugh !!!! see http://www.madabout-kitcars.com/images/imgtxt/700/1172057836-dut3.jpg
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.
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.
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?
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.
WSCC Speed Series Champion:
[Edited on 5/3/07 by TimC]
"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.
You could fully pan the bottom and go this route..
Description
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
quote:
Originally posted by smart51
A well designed lip spoiler will reduce lift at the rear no matter how much drag the front wheels create.
Simple way to get a little free high speed down force and a drag reduction is to setup the car so the bottom of the chassis is 25mm lower at the front than the rear.
quote:
Originally posted by britishtrident
quote:
Originally posted by smart51
A well designed lip spoiler will reduce lift at the rear no matter how much drag the front wheels create.
Actually it won't do anything it is sitting in a massive area of chaotic turbulent back flow.
To get a rear spoiler or rear wing to work it has to be in clean airflow, even if the windscreen is left off and the driver lowered as far into the
car as possible the airflow at that point on a Locost as brocken down into turbulence.
The only way to clean airflow on to a rear aerodynamic device on a seven style car is increase the height greatly -- just look at how Clubmans racers
developed from the original Lotus 7 and Mallock U2.
Chapman of course did build a much aerodynamic version of the Seven --- the Eleven.
The caterham 21 was an aerodynamic 7 too. I really liked the 21, but not for the money.
Have a search for some of Rob Palin's posts on aerodynamics - he does aerodynamics for a living.
http://www.locostbuilders.co.uk/viewthread.php?tid=58197&page=2
Similar topic with some interesting views
You're just being silly
I was going to point out the obvious - that lift is generated by air travelling (faster, therefore thinner) over a longer distance (ie over top of
car), trying to catch up with with the air going underneath.
Easy to fix. Don't let any air go under car. I'm probably going to go diffuser route ar rear of mine, and (because of the turbos) have under
engine bay "scoops" that remove air from under car and chuck it through side panels.
ATB
Simon
Need I say more?
quote:
Originally posted by smart51
It seems idiotic to me that people say "sevens are aerodynamically bad. You can do nothing about it and you are stupid if you think you can."
quote:
Originally posted by MikeRJ
quote:
Originally posted by smart51
It seems idiotic to me that people say "sevens are aerodynamically bad. You can do nothing about it and you are stupid if you think you can."
If makes more sense when you add on "without totally ruining it's looks".
A caterham with an aeroscreen has a drag coefficient of 0.29
Aerodynamics of a brick my backside...
I can hit 156mph and hit the rev limiter in top gear,running 240bhp at the wheels, I was allways told that I'd never get it over 135!!!
aerodynamics
on a track of course
[Edited on 26/3/07 by dilley]
156!!
Now that must feel 'Interesting' in a 7.
its ok as long the car is setup properly.
you could always do something with the rollbar possibly?? its at the height to make a difference and tubes as far as i'm aware aren't very
aerodynamic.
I'm not talking anything outlandish, just make it less like a tube and more like a spoiler, shouldn't be that difficult with some grp?
Don't know how much effect it would have but its something.
cheers
Tweek
ps. feel free to correct me as my knowledge is sketchy at best. Just tryin that whole thinkin outside the box thingy