How Come R32s Have Such Crappy Drag?

[TurboDoseBro]

Hey guys, just want to start off with some drag coefficient values:

Nissan R32 GTR = 0.4 Cd

Nissan R33 GTR = 0.35 Cd

Nissan R34 GTR = 0.34 Cd

Subaru Impreza STi 2004 = 0.33 Cd

Nissan Cube = 0.35 Cd

A freaken Impreza (peanut/tear drop eye) STi with it's massive scoop, 4 doors, bulky appearance is better than the aerodynamics of the R32, despite the sleek look. I feel that on the freeway i gotta give it a bit more gas than my previous Impreza because of the drag is creates. Is the aerodynamics a big issue for anybody else? How important is this in motorsport/track days? Just feel that the R32 has so much more potential if it were more aerodynamic.

Edited September 6, 2010 by TyresBro

[iplen]

It certainly effects them a lot, but the issue is also that at that point the car had to be designed to work on the race track with out any body modifications, and race cars need down force, which creates drag, this is my theory. Pretty sure the other reason might be that it was not to well thought out or designed..... I am actually thinking about removing rear wing and trying reduce drag a bit next time I go to the strip to see what diff it makes

[xALmoN]

toyota supra, 0.31

[NISMO]

You're comparing a 1989 shape car with a 2004 impreza???

I think there's your answer.

Cd is more than just a sleek look. eg Lambo Countach - 0.42

That aside though, I've honestly never felt it. And I'm going to a 32 GTR from a car with a 0.27Cd - V35 Coupe.

[PM-R33]

R35 GTR 0.27!

Damn you beat me to it

Edited September 6, 2010 by PM-R33

[TurboDoseBro]

lol Dewds, I can pick out a lot of cars made around 1992 for a lot less Cd (eg. RX-7, Supra as mentioned, Civic, 180SX etc). It's just that there seem to be 2 different types of Cd, one for crappy body design, and the other is downforce. Read around and apparently the area of the front has a major role in aerodynamics too. Feels like such a handicap...

On the other note, would LOVE to see some wind tunnel testing of an R32 to determine if it's putting the Cd to good use.

Edited September 6, 2010 by TyresBro

[syfon]

Even if the R32 has a slightly high drag co-efficient, it would make shit all difference at speeds up to maximum legal speed limit of 110km/h. Drag co-efficients only REALLY come into play when you are talking about serious top-end drag racing (ie 7secs and lower) or serious circuit racing like the FIA GT1 champs etc.

I highly doubt you would be able to feel the difference on the freeway.

[NISMO]

  TyresBro said:

......Feels like such a handicap...

  syfon said:

Even if the R32 has a slightly high drag co-efficient, it would make shit all difference at speeds up to maximum legal speed limit of 110km/h. Drag co-efficients only REALLY come into play when you are talking about serious top-end drag racing (ie 7secs and lower) or serious circuit racing like the FIA GT1 champs etc.

I highly doubt you would be able to feel the difference on the freeway.

Completely agree, and what i was trying to get at. I connot feel the difference at all between the V35 and the R32. (see my post above for the difference in the two)

And thats both cars on the track at both Wakefield and Oran Park, really don't know how the OP sees it as "such a handicap"

[toddlls]

Regardless of the Cd rating they still handed the V8 Falcons & Holdens their asses at Bathurst & every other type of vehicle they raced against when they were released-including the Cosworth Sierra's.

I dont believe that its such a handicap tho-look at Victor Bray in that old school Chev, has the aerodynamics of a house brick but it still hauls ass ,so is it really that important considering the car was made in '92

[TurboDoseBro]

The mainly noticable differences are on the freeway and downhills. The moment you let go of the accelerator, the car starts slowing down where as other cars start coasting or even roll faster. I'm not saying it like it's running on 3 wheels, but as the air drag increases as a square of speed, it exponentially increases the resistance and feel at higher speeds. That is where we have the disadvantage compared to other cars or similar class.

[mad082]

  toddlls said:

Regardless of the Cd rating they still handed the V8 Falcons & Holdens their asses at Bathurst & every other type of vehicle they raced against when they were released-including the Cosworth Sierra's.

I dont believe that its such a handicap tho-look at Victor Bray in that old school Chev, has the aerodynamics of a house brick but it still hauls ass

<facepalm>

  TyresBro said:

The mainly noticable differences are on the freeway and downhills. The moment you let go of the accelerator, the car starts slowing down where as other cars start coasting or even roll faster. I'm not saying it like it's running on 3 wheels, but as the air drag increases as a square of speed, it exponentially increases the resistance and feel at higher speeds. That is where we have the disadvantage compared to other cars or similar class.

so many other things be coming into play there than aerodynamics. you could have a slightly sticking brake piston, poor wheel alignment, crappy wheel bearings, tight diff, etc. the gear ratios could also come into it because of how the engine responds when just left on compression braking. the higher the revs the more it will slow down when you lift off. the width and tread pattern of tyres can also come into play.

you would really need to compare your car to another car with all the same mods and then see how it performs.

[Munkyb0y]

cant believe a cube has better aerodynamics than a 32. LOLZ.

but as mentioned. everything else on and about your car will have more affect than the CD at freeway speeds.

your tyres for example. wide, sticky, agressive tread pattern. that will slow you down. gearing, that will do it. fat gf, that will definitely do it. ask boz.

[mad082]

  Munkyb0y said:

cant believe a cube has better aerodynamics than a 32. LOLZ.

but as mentioned. everything else on and about your car will have more affect than the CD at freeway speeds.

your tyres for example. wide, sticky, agressive tread pattern. that will slow you down. gearing, that will do it. fat gf, that will definitely do it. ask boz.

baaaaaaaaaaaaaaaaaaaaahahahahahahahahahahahaha

*wipes away tear

aaaaaaaaaaaaaaahahahahahaha

[toddlls]

Is there anyone in here doin Aerospace Engineering or works in a Wind Tunnel facility that can actually answer this Q?

[warps]

  TyresBro said:

A freaken Impreza (peanut/tear drop eye) STi with it's massive scoop, 4 doors, bulky appearance is better than the aerodynamics of the R32,

Quite simple, really

Subaru >> Nissan

Seriously though, the aerodynamics are really onlu going to have a significant impact at speeds above 150km/h or so. At 100, you're chewing up less than 20kW in overcoming the aerodynamic drag.

Having said that, reducing drag has a much bigger impact on top speed than increasing power. A doubling of power would increase top speed by about 13% (rough rule of thumb figures - obviously a lot of other things come into play)

The CD figure is a pretty basic number used to define a car's overall aerodynamic drag. Essentially it is saying how much drag your car has compared to a house brick with the same frontal area as your car (putting it simply).

CD is a comparison of the car's actual drag to the theoretical drag which is calculated from stagnation pressure (1/2 x air density x speed^2) x frontal area. This calculation gives a drag coefficient of 1:1. Your car's drag coefficient is the actual drag divided by the theoretical (house brick) drag

edit: this is my recollection from studying this stuff 25 years ago, so I might have missed some fine details.

Edited September 8, 2010 by warps

[toddlls]

  warps said:

Quite simple, really

Subaru >> Nissan

Seriously though, the aerodynamics are really onlu going to have a significant impact at speeds above 150km/h or so. At 100, you're chewing up less than 20kW in overcoming the aerodynamic drag.

Having said that, reducing drag has a much bigger impact on top speed than increasing power. A doubling of power would increase top speed by about 13% (rough rule of thumb figures - obviously a lot of other things come into play)

The CD figure is a pretty basic number used to define a car's overall aerodynamic drag. Essentially it is saying how much drag your car has compared to a house brick with the same frontal area as your car (putting it simply).

Thanks-that clears things a lil

I dont know much about this type of stuff-am hoping to understand it all a little

[toddlls]

More to the point I guess is there any proven way to improve the cars performance with 1 type of body kit over another or perhaps or even paint finishings.

ie Kiwi yachtsmen use lanolin on their hulls to improve the boats slip through the water & powerboaters use it for better fuel economy-not possible on the car but??????????

[Beelzebub89]

There are plenty of other problems with 32s before you should worry about drag coefficient really.

[xALmoN]

no wonder the gtr has such shitty fc...

[SMOKEYV35]

clearly it has nothing to do with a sleek 'looking' shape - the LS400 when released had the lowest drag coefficient of any production car at the time 0.29 - and that thing has a front end on it like a tugboat.