MOTORSPORT
The front guards (fenders) will
be ventilated so that they have
an aerodynamic effect as well as
helping with brake cooling. There
are LMP like cut-outs in the front
guards to relieve the pressure and
reduce lift as well.”
“We had to rebuild the radiators
and repositioned them for the new
engine. The radiators have been
moved forward and the exhaust
mufflers have been completely
reconfigured with the final
exhaust exit through the side just
in front of the rear wheels,” says
Ryall.
“In the really early days I was
experimenting with different diffuser
shapes, locations and heights on
my old racecar,” continues Ryall.
“When I realised how even ill-informed
manipulation of things like
the diffuser could affect the driver
experience and the downforce,
I decided to do some proper
aerodynamic analysis for this
project.”
The car will suit New Zealand
tracks as they are quite a bit
smaller than European ones and
you need to have a racecar which
is relatively nimble. There are no
long fast corners on NZ tracks -
nimble and light is the key.
“Because of the new wheels, tyres
and drivetrain we've redesigned
the uprights - the original Juno
ones are too big,” says Ryall. “We
are planning to remake the rear
lower wishbones with aero-profile
tube to reduce the interference
to the airflow through and around
the tunnels. The upper wishbones
can be standard as they are not
exposed to the airflow.
“We allowed 30 mm of suspension
movement, which is quite a lot for
this kind of car,” says Ryall. “The
front of the car will hit the track
before the 30mm of suspension
movement is achieved, so it's not
really a car bumpy circuits. The
suspension is adjustable so we can
vary the ride height according to
the circuit.”
There are two sets of front guard
outers for the different tyre sizes.
“We didn't want to make two
moulds so we made a spacer for
the front guard mould to produce
a shallower front guard for the
narrower tyre,” says Ryall.
The light lenses came out very
well from the vacuum forming
process with no wrinkling at the
corners. “The vacuum forming
mould was fibreglass,” says Ryall.
“The same process for LMP cars
uses aluminium moulds, which
cost probably 10 times as much.
The light lens is attached to the
mould and the carbon guard is
moulded around it so it's a perfect
fit. Because of the relatively low
temperature curing the lens is not
affected by the heat. Apart from
being an elegant solution it also
saves on fixtures for the light lens
and the carbon resin bond is a lot
stronger than if the lens was glued
in afterwards.”
The lens material can tolerate
150°C and the temperature in the
oven is typically only 90°C. “Most
of the people we've spoken to
about this idea, told us it couldn't
be done, but we've managed to
do it,” says Ryall. “By vacuum
forming the lens against a mould
taken from the same plug as the
guard mould we have achieved
a lens that will then fit precisely
into the carbon guard mould and
be located by its shape relative to
the mould, when the mould, with
the carbon layup, is subjected to
vacuum.”
The fasteners are also moulded
with the panels rather than being
drilled and glued in afterwards. The
fittings for the major components
will be the bonded AeroCatch
fittings, which will also be bonded
in the mould so that they will be
as flush with the surface of the
panel as much as possible. One
of the original design criteria was
to use all flush mounted fasteners.
A lot of the lighter panels are held
place using a ratchet quick release
aerospace fastener.
Many of the flush fasteners
available require expensive
specialist tools to install them. By
gluing the fastener in the mould
and then moulding the panel
around the fastener the installation
is much quicker and more
accurate.
The logical passenger side of the
cockpit will be covered with a ‘faired
in’ composite tonneau cover, so the
cockpit experience is relatively snug.
The rules dictate that the driver has
to sit on one side of the car so the
driver’s head is right or left of the
centreline for it to be called a sports
car as opposed to a single seat racer.
The fuel tank is located centrally
directly behind the passenger space
and driver’s seat.
In the standard configuration the
Juno has a single bump behind
the driver and the intake snorkel
is usually on the passenger side.
There are usually two windscreen
bumps in front of the cockpit, but the
passenger side is flat on the inside,
so the passenger tonneau cover
panel will also fair this bump into the
rest of the aerodynamic surface.
“We are not using the standard
airbox as it doesn't really work with
our bodywork,” says Ryall. “We have
built moulds and made our own air
boxes.”
All the panels have rebates and
offsets so that they fit together
exactly, with very small and precise
shut lines which offer a very clean
and smooth aerodynamic surface.
This car has taken on its own bold
identity and no longer resembles a
Juno hence the name change. This
project has produced a professional
racecar by enthusiastic grassroots
racers without the big budgets of the
larger companies.
"THE LENS
MATERIAL CAN
TOLERATE
150°C AND THE
TEMPERATURE
IN THE OVEN
IS TYPICALLY
ONLY 90°C"
22 August 2019