Assphalt Kicker wrote:
ya after posting what i said, i looked over it while sketching my ideas out for ya to better under stand, then remember the airfoil is the opposite direction of down force, so i went awww i screwed up the explination...
take the whole fender as airfoils and reverse that thought,
Somehow I can't picture of how having the air foil -under- the tire is going to work! But carry on. 
use the pressure of the air going over the fenders as a way to compress the suspension down into the pavement...
A small flat plate at the correct angle could do that. the whole point of making the fenders to produce more downforce, is beacuse they would be aerodynamic then those shapeless un-aerodynamic fenders that u have on ur lotus7's...
But they are smooth, round and don't rotate as the tires do.............
This is where I think you are making a bad assumption. Most things that produces downforce do so at the expense of producing more aerodynamic drag.
And the big question is still, do we need (more) down force on a Locost which probably doesn't have much built in lift at the "high" speeds they can run at to start with. the downforce issue is just something that comes with aerodynamic asspect of the re-designed fenders!
Truthfully I have an idea that there is so much turbulence at the rear tires caused by the disrupted air flow from the -front- tires and windshield that the shape of the present rear fenders probably don't matter that much.
Under ideal conditions, the aerodynamics of the complete car should only produce a small amount of down force at high speeds. Just enough to make the car remain stable and not cause drag. Most cars (belly tankers notwithstanding) are sort of flat on the bottom and tend to produce lift at one end or the other at high speeds. That's when some shape tweaking can reduce the lift.
Now on Jack's car where he is streamlining the air flow around the front tires the rear tire area could more benefit from streamlining. Which he intends to do.
Down force itself isn't a particularly good thing if you don't need it. It puts more stress on the chassis etc. The suspension has to be designed as if the car was heavier etc etc. which can make the car ride rough at slow speeds.
The down force on a F1 car and Indy cars is so great that the car could drive on the ceiling at high speeds. Ever notice how badly an Indy car bounces when they run over the berms? The springs are set up for a ~2800 mass car which really weights ~1/2 that at slower speeds.i believe the whole point of the front balance is to divert air away from the suspension pieces and throw air going under the car into the radiator (increasing cooling)
If you want to reduce air flow under the car just make the car -lower- or use a small air dam or a small strip of metal across the front of the chassis.
The suspension pieces are -along side- of the radiator not under the radiator. If you really needed all that cooling air you would have to have some sort of scoops to the left and right of the nose cone to channel the air into the nose cone opening.
The opening in the nose cone can be quite a bit -smaller- than the area of the radiator and still provide enough cooling air as long as the distance from the nose cone opening to the radiator is long enough to allow the air to slow down (with the radiator shrouded). In other words, you need sufficient volume inside the nose cone in front of the radiator to allow the air to slow down (and expand) before entering the radiator core. and also throw it over the car... this would create a massive amount of air flow over the top of the car,
Which could cause lift. If the car is low enough most of the air will go over or along side of the car as it is. There's no place else the air could go. and basically almost no air under the car, and this stops air pockets getting under ur car and flipping u end over end
!!!!!!!!!! Unless you have a very fast car (150 MPH or so) and a lot of up nose attitude, I really doubt that a Locost is going to take off! NASCAR cars take off at ~190+ MPH -AFTER- they get lifted in an accident.now this is in general car speak, i don't know any lotus7 that was thrown end over end cause it had too much low pressure under the car and threw its front end into the air, but im just speaking openly, im pointing what creates the most drag on a lotus7 and how it could be adressed to improve aerodynamics, which will create downforce
To improve the aerodynamics of a brick you generally taper the forward and rear ends of the brick. If you do it correctly the streamlining -doesn't- produce lift. If you don't have lift you don't need to screw up the aerodynamics of the car with drag inducing down force devices or shapes.
For example, time after time on TV coverage of NASCAR racing you will see the pit crew making small changes to the rear wicket. The announcers (some of whom are ex-crew chiefs) will explain what the pit crew is doing doing and then say something like, "They are increasing the down force which will reduce the top speed slightly." also the downforce on the fenders is created by the amount of airlow over the fenders, and unfortunetly the more air over the fender causes downforce,
Now in affect, your saying that down force is bad?and that huge amount of air is due mostly at high speeds, were u don't really need the downforce! but it is aerodynamic
Really? That is when you might need down force. You aren't going to produce much down force at LOW speeds.
Down force is normally needed because at high speeds the shape of the car is producing a lot of LIFT. At some point, the car can develop so much lift that the tires can't put more power down on the road due to tire spin and the car becomes unstable.
The early GT-40s at Le Mans during practice for instance became so unstable at 180 MPH that at least one of them crashed. Ford took the cars back to the wind tunnel and started putting various chin spoilers, tail wickets etc on the body to induce down force to cure the problem.
The 1960s Studebaker Hawk had for the time, a nice streamlined looking coupe that people were running at Bonneville. The car had bad rear end lift at ~180 MPH and the cars wouldn't go any faster. The hot roders had a quick cure by running a large diameter (4"??) hose from a high pressure point -under- the car, through the trunk with the hose exit behind the rear window. This reduced the lift with practically no penalty in drag and the cars started going over 200 MPH.
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A'kicker, I'm not picking on you just to pick.
You do have some good ideas but they aren't always thought out thoroughly. I'm just poking at you to get you to read more to really understand the principles behind what you are suggesting.
Most things are compromises. If you change one thing (the shape of the fender for instance) other problems can be emphasized. You correct that and another thing can happen etc. Don't forget people have been racing 7s since the early 1960s and the problems you are addressing aren't new.
The 7 is such a brick to start with that if you do streamline it, which people have done, they look strange and for most people they loose the "look" that a 7 has. It still quacks like a duck, but starts to look like a goose.
Do a Wikipedia search on "down force". Also read up on the 1907 Stanley Steamer speed record crash. The flat bottomed car took off after hitting a small bump which raised the front of the car slightly.
NASCARS take off sometimes when they get spun around backwards. Why? What are those flip up panels -really- doing on the roof of NASCARs etc.?
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