Home' V8X Supercar Magazine : Feb March 2014 Issue 79 Contents 65
big, fast cars; they need downforce to help cope with
high-speed straights and corners such as Conrod and
the Chase at Bathurst.
In their natural state most of these three-box sedans
do not generate a lot of high-speed downforce because
they are shaped to be slippery through the air to max-
imise fuel efficiency.
Equalisation: without aero assistance the differences
in performance between the current five makes would
be far more pronounced, so the aero testing process
pretty much eradicates that. Or is intended to.
Performance: the aerodynamic kit fitted to V8s is
tuneable, therefore it is possible to gain a speed advan-
tage or, if you go the wrong way, a disadvantage.
Think of the performance of the wildcard Xbox
Commodore at Bathurst last October. Triple Eight
design guru Ludo Lacroix intentionally set it up with
low drag for internationals Matthias Ekstrom and
Andy Priaulx. Because they were never going to be the
fastest across the top, the car’s speed in straight line
enabled them to attack and defend up and down the
However, it is important to stress V8s are not what
you would call an aerodynamically driven. Check out a
DTM touring car (left) if you want to see that.
“V8 Supercar is probably more governed by the
engine, more governed by the mechanical grip,” says
Lacroix. “The downforce is an add-on, it’s a plus and
you want every plus. In a field that is separated by a
second, every plus is better.”
Presentation: a key principle of V8 Supercars is the
cars retain a production look, even though they sit a
control 2822mm wheelbase and have the length of the
body between the axles modified to fit the template.
Aero is necessarily limited to preserve that look. For
instance, only from below the bumper can re-shaping
of the front-end take place.
Anyone wishing to develop a V8 Supercar is provided
with a homologation handbook that goes through
what’s allowed and what’s not, including aerodynam-
The aerodynamic basis has not changed in the
transition from Blueprint to CotF; the cars still have a
front splitter, an undertray, side skirts, a rear diffuser
and a simple rear wing that has an adjustable gurney
flap on its trailing edge. The wing has a specified chord
(width), adjusts through only a narrow range and can
be centre or outboard mounted.
Thanks to CotF, aero designers do have some new
wrinkles to deal with because of such things as the
shifting of the fuel tank up and forward of the rear
axle. This has made air exiting under the body much
easier to manage.
The underbody is also very uniform across the four
makes. Everyone uses the same chassis, rear axle and
brakes and most use the same Triple Eight front-end.
Essentially, that means the body defines the aero
qualities of each race car, three of which are new for
2013: the Commodore VF, Mercedes-Benz E63 AMG
and Nissan Altima. The Falcon FG was the carry-over
body and served as the baseline.
The aero design for each was developed by the man-
ufacturer and its homologation team – Triple Eight,
HWA in Germany with Erebus and Nissan Motorsport
for the Altima (FPR looked after the FG in consultation
with V8 Supercars’ technical department).
Before any part went through the expensive transla-
tion from CAD to three-dimensional reality it had to
first get the official stamp of approval.
Initial solo testing looks for any teething issues and
then comes back-to-back testing using the now widely
referenced – and sometimes questioned – 200km/h
It’s literally what it says it is, the car accelerates
to the cut-out in fifth gear (flat-out in fifth) and the
downforce and drag the car generates is monitored as
it decelerates from 200km/h.
Before the cars roll out they are equalised as much
as possible; V8 Supercars suppliers specific dampers
and linear springs, anti-roll bars are disconnected and
a mechanical drag test using draw bar-mounted load
cell is conducted.
Through that process shapes are reprofiled, angles
sharpened or blunted depending on what the testing
shows. The intention is to find a middle ground that
aligns each car as closely as possible in terms of aero-
dynamic grip and progress through the air.
At the end of the process, which is attended by the
relevant V8 Supercars and team technical personnel, it
is a requirement that representatives from each team
sign off on every car’s downforce and drag figures.
From quite early in the 2013 season it became
apparent the Nissan Altima lacked high-end straight-
line speed. Initial focus centred on the VK56DE engine
but as that improved and the car continued to hit a
brick wall above 220km/h, so attention turned to the
In its production state the Altima is not an easy
car to tune aerodynamically for racing. At high speed,
because of its slippery fuel-saving shape, it generates
lift rather than downforce. Combine this with a short
rear overhang that makes air coming off the body
above: holden’s VF
commodore introduced a
new end-plated rear wing
for the manufacturer.
V8X79 p64-66 Body Shape Aero.indd 65
10/12/13 5:47:42 PM
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