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Coefficient of Drag for Many Veh's


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For posterity's sake, here is a site I came across while surfing the web. It lists a whole slew of Cd's for different veh's.

 

http://www.teknett.com/pwp/drmayf/tbls.htm

 

This site should help those who may have built a custom car & dont know the Cd of that car; now you can find a similar car's Cd & get somewhat close by mathing another car's Cd whose front end is somewhat similar.

 

And No, this site doesnt list the Cd for our Z's...but we, HybridZ, has already listed the 1st genZ's Cd in other threads-so do a search for that or someone here should have that info readily available: just ask if you need it.

 

Kevin,

(Yea,Still an Inliner)

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280zx

OK, you probably got this part. ;)

 

CD 0.340

Coefficient of drag. Its used in a lot of fluid mechanics calculations. It is equal to: (Drag force)/((1/2)*fluid density*velocity^2*size scale^2)

 

Area (m2 ) 1.827

Frontal area of the car in square meters. Basically if you took a silhouette of the car and measured the area of the shaded part... The next one is in square feet instead of square meters.

 

Cd x m2 0.62

Pretty self expanitory... Coeficient of drag times frontal area. Next one is in square feet for you non-metric types.

 

I didn't realize the 280zx was so much better than the early Z aerodynamically... (the early Z has a Cd of ~0.45)

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Guest Thurem

Drax

I didn't realize the 280zx was so much better than the early Z aerodynamically... (the early Z has a Cd of ~0.45)

You have to remember the formula for looks, the Z looks about 3 times better than the ZX, so we have for the Z 0.45*1=0.45 and the ZX 0.34*3=1.02 clearly the Z comes out way on top, looking way sleeker.

(sorry ZX'ers, could not help myself) :lol:

Thure

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Guest comeandzpa

some of the current cars (exact examples slip my mind....) get even lower than that. I think the Mercedes coupe hits as low as .26. Pretty impressive, if you ask me. Wonder what their G-wagen is, or the H2 hits?

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  • 2 weeks later...
Guest DaneL24

Those sleek headlight covers should definitely help with the frontal aerodynamics of a Z. The area under the grill probably catches a lot of air too, causing more drag. The only major problem I see other than the headlight design is how the rear hatch slopes smoothly and then turns straight down...must make quite a bit of turbulence and suction effect behind the car.

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the Z's Cd was 0.467, for the 280ZX they spent six months refining the design using a wind tunnel to get the Cd down to 0.385 which was a major leap forward for it's time.

Additionaly lift was reduced by 60% and sidewind stability was significantly improved.

(I got this info from Brian Long's book called datsun 280zx/nissan 300zx)

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Guest comeandzpa

as an interesting side note, the new Mercedes-Benz Maybach (weight-6000+ lbs) has a cD of .30....0-60 in 4.9, 1/4 in 13.9. Amazing......

 

Sorry, I misread the specs. the 1/4 time is 13.4, not 13.9. Sorry for the confusion!

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  • 4 weeks later...

to be more exact the drag coefficient is calculated to be

 

Cd = Cdo + K*Cl^2

 

Cdo = zero lift drag (an object being in the way, sort off)

 

Cl = is lift coefficient

 

K = 1/ (AR*e*pi) == look up in the Aero books you will find this

 

AR = aspect ratio, for siplicity ratio of length of the car vs. width of the car so for cars is is much smaller then 1 and for wings it is the other way around. there fore wider is better.

 

If you kill most of the lift you will reduce drag, my desire is to do some profile calculation and tell you how low can we go on the drag.

 

and 0.475 for first gen Z, you are all killing me, no wonder it is almost flying

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