i seen this on a post i came across... guy seem to know what he's talkin about. but in part terms... what should i look into doing... of top of my head i would assume..lowering the car....and a spolier. but what type? i seen spoiler as low as 3 inches. or as high at maybe 9 or so?
. what's the best height spoiler.. and what about a front splitter...what kind should i get...


RE: Does anyone have any interest in drag reduction? - 5/18/2005 3:19:35 PM

mechengineer201
Daily Commuter

Posts: 88
Joined: 5/16/2005
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Dude what are you talking about? Mach 1? and spoilers dont give you downforce - wings (lifting airfoils) do and all wings add drag - spoilers are for reduction of trailing vorticies (tumbling of air) when it frees itself from sticking to your car (have u ever driven with snow on your car and seen it go swirling off the back, thats what happens all the time - you just cant see it) and a splitter which goes on the front (an air dam) keeps air from getting under the vehicle and sticking to the bottom surface creating friction drag. I don't think you have any idea what you are talking about with drag - there are two forms: pressure and friction and on cars pressure drag is the most significant. And with gas prices being so high why do you think they post drag coefficients in vehicle specifications now? Just to give you an idea of how much force opposes you at 70 mph on the freeway i'll run thru some calcs:

On a 70°F day the density of air is 0.00233 slug/ft^3

70 mph = 102.7 ft/s

The drag coefficient of a 2g neon is about 0.34 and the frontal area is about 23.6 sq. ft.

Drag Force = 0.5 * (air density) * (frontal area) * (drag coeff) * (speed)^2

Do the math and your get a drag force of 98.6 lb at 70 mph

Power is force times velocity so if you do this and note that there are 550 ft-lb/s in a horsepower you get:

18 Hp getting sapped away by the air!!! - not good when most standard neons are lucky to have 110 hp max at the wheels,
thats over 16% of max!!

Now at 100 mph this jumps to 201 lb and almost 54 Hp!!! and when you consider wheel hp is what drives you, this is huge, almost 50%!!

Lowering drag is essentially like adding wheel hp at higher speeds

A 15% reduction in the drag coeff, which is entirely possible could drop these numbers to:

15.7 hp (~13% increase in effective wheel power) at 70 mph and

45.7 hp (~15 % increase in effective wheel power) at 100 mph

Aerodynamic drag is evil and limits your top speed (unless the computer does first), your fuel consumption per mile, quarter mile times, etc....certainly not only applicable at supersonic speeds.

 

i thougbht the lip spoiler would lift and a rear spoiler pushes down for more weight on the rear drive cars but hey i guess iwas wrong

 

Hey if I were you I would gop with something around the height of an srt-4 wing. WINGSWEST makes some awesome spoiler for your application.