drag coefficients

D0cks

New Member
Aug 5, 2003
94
0
0
which fox had the best coefficient??? i heard somewhere that a LX hatch had the best but im not sure if thats true. how does LX hatch vs LX notch vs GT all work out? Does anyone have numbers??
 
  • Sponsors (?)


I can't remember where I read it, but I believe the LX hatches have the lowest drag coeff. of the three. Of course, they are all pretty brickish. The 94-98 cars have the least drag with the 99 and up cars trailing slightly.


On a side note, Car and Driver did a test of a 96-98 Cobra with and without the wing. The car gained about 4-5 mph on the topend, approx. 155mph, with the wing removed. :rlaugh:
 
They covered this over on the Corral.. try searching over there. If i remember correctly, the lx notch came out on top by like .02 or something. As it turns out, the fox body mustang isn't that much of a "brick" as people think, and now that i know that, every time people say that it kinda pisses me off because they dont know the half of it...
 
why do you care about drag coefficients? are you planning on running at 150+ for extended periods of time, or having ETs in the 8s? Even if you were the drag coefficient can be altered significanlty with the addition of a spoiler to the back of your "brickish" car. The front of the car has little to do with the drag coefficient. The wake caused in the air at the back of the car is what effects the drag almost exclusively, with the addition of a longer sproiler such as the steeda spoiler, or a sheet metal spoiler seen on many 5.0 drag cars, this can be minimized along with the drag. A cylindrical shape is actually the worst for drag, so looks can be decieving round body lines don't necessary make a car better. Some manufacturers actually put the antennas in the windshield and make holes in the supports for the side mirrors for gas milage purposes. Even though the fronts of the side mirrors are rounded they cause significant drag.
 
I'd take what I read in the link with a grain of salt - there are errors in it (lighter weight car has higher top speed - incorrect; chrome moly steel is much lighter than mild steel - incorrect, the weight is similar, but chrome moly steel is stronger, so parts can be made smaller/lighter and have the same strength). Aerodynamics is extremely complex and counterintuitive. There are changes you can make that you'd think would reduce drag that don't; there are changes you'd think would have little effect that make a big difference. In general, you've seen cars become more rounded - not just in the front, but from front to back and top to bottom as well. If you think of the shape a rain drop or tear drop makes while falling - that's the most efficient shape for reducing drag. It's not practical for cars - but the general shapes of cars have been heading in that direction for years. Big improvements have also been made in the way that air through the radiator is channeled and how air moves underneath the car. Having said all that, I don't have a clue which Stang has the lowest drag coefficient. But remember - lowest drag coefficient doesn't necessarily mean the lowest drag. You have to multiply the drag coefficient times the frontal area.
 
Mavrick said:
They covered this over on the Corral.. try searching over there. If i remember correctly, the lx notch came out on top by like .02 or something. As it turns out, the fox body mustang isn't that much of a "brick" as people think, and now that i know that, every time people say that it kinda pisses me off because they dont know the half of it...

Well if you're gonna get pissed off, at least get your numbers right :rolleyes:
87-93 Mustang CD~.39
some comparisons..
3rd gen. Camaro CD~.37
present day Chrystler Concorde CD~.288!

Typical cars these days have a CD of around .30 - .35
Sports cars range around .25-.30
SUV's usually range from .35 - .45!!

cough..brick..cough :p


here's some links for ya ;)
http://www.mustangregistry.org/lx_87_89.htm
http://www.automotive-technology.com/projects/concorde/index.html#concorde4
http://encyclopedia.thefreedictionary.com/Drag coefficient

I rest my case...
 
As Mr. Yonts pointed out, there are many factors that determine drag coefficients and overall drag on a car. Adding a different wing may indeed reduce drag, but you tend to get a reduction in downforce when you reduce drag created by the rear wing.

Drag coefficient is a number that is multiplied by the total frontal area of a vehicle to obtain drag or more accurately drag force. Think of drag as a giant hand pushing on the front of the car. Any verticle surface adds to the frontal area, so spoilers, wings and so on add drag. The benefits of these devices, downforce, tends to outway the negative impact of drag. For example, a race car may give up speed on the straightaway for more downforce on a track with a lot of corners. Especially, if it makes the driver more confident in the car.

On street cars, low drag numbers are usually sought to reduce fuel consumption and wind noise.
 
Michael Yount said:
But remember - lowest drag coefficient doesn't necessarily mean the lowest drag. You have to multiply the drag coefficient times the frontal area.


I beleive frontal area is already taken into account when calculating the Cd of an object.

Or at least that's what i think. Trying to remember all the equations i used when working with wind tunnels but it's been a year or so.
 
Mustang5L5 said:
I've seen some numbers showing the LX hatch CD of about 0.34

right, hence the "~" (approximately). The hatch is said to have a CD of about .35 while the notch is said to be at about .40. Mavrick said .02 which is waaaaaay off! I don't know if that's even possible.
 
Qwk88LX said:
right, hence the "~" (approximately). The hatch is said to have a CD of about .35 while the notch is said to be at about .40. Mavrick said .02 which is waaaaaay off! I don't know if that's even possible.

I said i thought "the notch came out on top by like .02" - meaning the notch was .02 less of a "brick" then a hatch etc. Get your **** straight.

EDIT: Obviously i was wrong thinking that the coupe was more aero than the hatch... but thats cause i own one, i always think they're better :p
 
Mavrick said:
I said i thought "the notch came out on top by like .02" - meaning the notch was .02 less of a "brick" then a hatch etc. Get your **** straight.

ok, my mistake..take it easy..jeez. You're still off when you say the notch came out on top...the hatch is more aerodynamic because of the gradual angle the hatch comes down at compared to the notch. :D