Holden Commodore Aerodynamics

[galahs]

Just been looking at the drag drag coefficient of Commodores over the years and noticed I couldn't find the VE Commodore and FG Falcons figures.
(Funny that now the VE Series 2 was released with its aero improvements, Holden was willing to release the VE's aero figures to show off how much better the Series 2 was. Shame it is still not even better than the VT/VX shape let alone VY/VZ)

Now a cars total aero drag is its drag coefficient (how slippery it is) multiplied by its cross sectional area (how wide and tall it is).

So a small car with a drag coefficient of 0.30 will have less aero drag than a large car with the same drag coefficient of 0.30 because it has a smaller cross sectional area.


Here is the drag coefficient details of some cars I have found...

VL Commodore = 0.43
VL Group A Walkinshaw = 0.32
VN Commodore = 0.34
VN Group A = Less than 0.30
VT Commodore = 0.32
Monaro = 0.31
VX Commodore = 0.329
VX Commodore SS Spoiler = 0.354
VY Commodore = 0.319
VY Commodore S Spoiler = 0.326
VY Commodore SS Spoiler = 0.334
VE Commodore = 0.354
VE Commodore Series II = 0.330
VE Commodore Series II + Rear Wing = 0.35+
VF Commodore = 0.30
WK Statesman = 0.30
ECOmmodore = 0.28

XF Falcon = 0.42
EA Falcon = 0.34
EF Falcon = 0.31
AU Falcon Sedan = 0.295
AU Falcon Wagon = 0.341

2010 Toyota Prius = 0.25
2002 Toyota Camry = 0.30
2003 Toyota Camry = 0.29
2010 Toyota Camry Hybrid = 0.27
2007 Toyota Aurion = 0.301
2007 Toyota Aurion Sportivo = 0.292


1996 TE Magna = 0.28

[galahs]

In these pics you can see how sleek the ECOmmodore and Monaro are.



The ECOmmodore came in at a slippery 0.28 thanks to the steeply raked rear window which flows nicely onto the boot lid. This profile is shared with the Monaro.




The sharp lip integrated into the Monaro Bootlid is a big improvement over the VT/VX sedans rounded trailing edge. Unfortunately the Monaro boot lid is not a direct swap item with the sedans.



It does however give a hint as to what sort of improvement is required to the VT/VX sedans boot to help reduce aero drag.

[galahs]

Some aero touches on Commodores.


The VN Commodores squared off rear wheel arch and the flat pizza pan style hub caps reduce drag.





The VP Calais rear wheel arch spats goes one step further reducing the wheel opening and in turn reducing drag.


Reducing the upper grill opening reduces drag as it promotes more air up and over the smooth bonnet than through the radiator (high drag)

VN Group A SS


VL Group A SS Walkinshaw


Even the standard VP upper grill is pretty aerodynamic

[galahs]

The under side of cars are not very aerodynamic with the exhaust pipes and suspension components hanging in the breeze.


The VT Commodore S & SS front skirt extension reduces air from going under the car. Again reducing drag.



same for the VS S and SS




the rear boot lip spoiler fitted to the VR and VS Commodore S pack also helps the cars aerodynamics by promoting a clean air separation.


as does the sharper trailing edge of the VY and VZ commodore. Much more aerodynamic than the rounded off VT and VX Commodore boot lid.

[galahs]

A front skirt that prevents air from hitting the front tyres also reduces drag as can be seen in these designs.





The side skirts also reduce drag by minimizing the air flow under the car where it will hit the rough underside of the vehicle.

[galahs]

Things that increase your cars drag.


Weather Shields



High Rear Spoilers
Rear spoilers often increase downforce which is beneficial for racing, but come at a cost in increased drag.




Mudflaps



Your roof racks also add to drag so take them off when you're not using them




Also bad for aerodynamic drag is open windows, open sunroofs, radio aerials, side mirrors, large radiator/brake intakes, bonnet scoops and windscreen wipers .

[galahs]

Aerodynamic improvements on the VE Series 2 include:
· Addition of panels under the vehicle floor to reduce airflow drag (sedan and Sportwagon, excluding Omega)
· Reduced trim height on Omega and Berlina sedan
· Air deflectors fitted to the front of sedan rear wheels (Omega, Berlina Calais)
· Rear decklid re-design to include aero lip detailing (sedans)
· Front undertray modified to reduce drag



Note the additional lip on the VE Series 2 bootlid to improve aerodynmics by promoting a cleaner air seperation.


The VE Series 2 SS and SV6 front bar has been redesigned to promote smoother air flow around the front wheels (the wheel arch flares introduced in the VE were a bad source of turbulence)

Air deflectors fitted to the front of sedan rear wheels (Omega, Berlina Calais) on the VE Series 2 Commodore






Change to front bumper helps to smooth the airflow around the cars front wheels on the VE Series 2 Commodore




Aero improvements

New under-body aero=smoothers.







Fascia and rear changes, with the more rounded nose and under-car trays combine to produce significantly lower drag. The undercar trays weigh almost nothing. Small rear wheel deflectors on the sedans channel air away from the wheelwells which reduces parasitic underbody drag. The small lip on the sedan bootlid is a minor but functional addition to smoothing the flow of air over the car. The new shape was wind-tunnel test-validated at the GM Windtunnel, Warren Michigan, and the Monash University windtunnel in Australia, as well as simulated in virtual reality.


Wind deflector - 'looks like some dummy fitted the mudflap wrong!"

VE Series II Commodore Tech - GM Inside News Forum


This is from Wheels Magazine October 2010

Drag Co-Efficients
VE Commodore Omega = 0.354
VE Commodore Omega Series II = 0.330
VE Commodore SS Series II = 0.35+ (extra drag due to cars rear wing)

The VE Commodores flared wheel arches add 0.02 to the drag co-efficient
Lowering the VE Series 2 by 10mm had improved the cars aerodynamics by forcing air up and over the smoother top surface of the car. It also helped fill in the wheel arch space.

[galahs]

You can read about the aerodynamic development of the VY Commodore here:

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AutoSpeed - The Aerodynamic Development of the VY Commodore - Part 2

[kach22i]

Originally Posted by galahs

Things that increase your cars drag.

Good list.

I'll add that aftermarket wheel flares add drag too.

Sample:
S10 4x4 Pick Up pictures by kach22i - Photobucket


On the Commodore I'm sure it would more like this:
random pics that YOU have taken....... - Page 290 - Pelican Parts Technical BBS

[galahs]

I saw an old V8 Supercar the other day that had a VT front end with a VY rear end.
Really that would be the ultimate combination of Commodore ends. A nice rounded front end and sharp edged rear end.

Throw in an upper grill block, a Holden by Design front and side skirts and you'd have a very slippery family saloon.