• Aluminium upright 5-axis billet machined in 7075-T6 and HARD
ANODISED
• TITANIUM bottom spindle with rolled threads
• Conical spacers in stainless steel for lower Ti spindle
• M16 nyloc nut for lower Ti spindle
• High tensile electroplated 12.9 grade bearing bolts M12
(specially made)
> REAR
Retail price: £1395.00 ex. VAT complete kit
• Aluminium upright 5-axis billet machined in 7075-T6 and HARD
ANODISED
• TITANIUM bottom main spindle with rolled threads
• Conical spacers in stainless steel for lower Ti spindle
• M16 nyloc nut for lower Ti spindle
• TITANIUM bottom toe-link spindle with rolled threads
• Conical spacers in stainless steel for toe-link Ti spindle
• M12 K-nut for toe-link Ti spindle
• High tensile electroplated 12.9 grade bearing bolts M12
(specially made)
> ACCESSORIES
•
Carbon brake disc cooling kit front (Brake disc insert and duct
ball).
Retail price: £485.00 ex. VAT complete kit
• Titanium caliper mounting studs with spacer bobbins and K-nuts
(set of 4 studs).
Retail price: £86.00 ex. VAT complete kit
• 18mm spherical bearing adapter kit (to convert the standard
tapered ball-joint on the end of the wishbone to an 18mm
spherical bearing.
Retail price: £545.00 ex. VAT complete kit
What are ‘Uprights’?
Often referred to as hubs, the upright is the large item that
contains the rotating hub and its bearings, and attaches to the
wishbones.
Nitron are now
making available the ultimate upright assembly, for the serious
racer, track user or enthusiast.
One of the main problems with the Elise, Exige and other similar
cars is that they are designed to run at a fairly high ride
height. For track use and even road use, lowering the car not
only makes it look better, but also makes it go round corners
better – or rather it should. However, Lotus have optimised
their suspension geometry to run at the designed ride height,
and lowering the car upsets this. Cars running on stock uprights
but with very low ride heights have very
poor suspension geometry.
What have we done?
By manufacturing uprights with the hub centre
raised by 25mm,
the car is effectively
lowered by this
amount without changing any of the suspension geometry. Any more
than this is limited really by the wheels and the wishbones.
We have spent months of design time to arrive at the
optimum solution
of raised hub, overall weight, increased stiffness, cooling
efficiency and overall packaging of the front and rear uprights
on the S2 cars (Toyota and K-series). S1 cars will become
available shortly.
Design Principle
The design concept was to use the entire upright as a vented
spool, as they do on F1 and Le Mans Sports Prototypes. This
means that the upright itself is
internally vented
and allows cold air from an intake duct to be pumped around the
bearing, CV joint at the rear, and then into the eye of the disc
bell and out through the vanes on the disc. This air is
controlled and kept within the upright itself, rather than lost
and wasted. A spool design of upright is
very stiff by the
nature of its own shape.
We have kept the Lotus design principle of steering arm, this is
very useful for changing the camber settings without affecting
the toe setting. We have increased the steering arm mounting
base for additional stiffness. The arm has also been
optimised for bump steer,
this can be adjusted for different conditions, i.e. the
Nurburgring to Silverstone, and minimises the bending load on
the mounting bolt, all making the driving experience more
predictable.
The front uprights take the standard AP or Alcon 4-pot caliper
(the original 2-pot will no longer fit), and the rear upright
has been designed to accept both the smaller AP 2-pot caliper
(originally fitted to the front) or our recommendation of the
4-pot as on the front, as the Toyota-engined cars are now
getting very rear heavy.
Finished Solution
The uprights are machined on a
5-axis machining
centre to incredible tolerances. They start off as a huge billet
of
7075-T6 aluminium
and through the very latest CAD-CAM systems they are turned into
the finished item. Each upright is on the CNC machine for about
8 hours. Once the upright is finished, it is sent away for
hard anodising,
then finished off back on the CNC machine to have its holes
finish tapped and counter-bored where required.
The upright is then finally assembled with extremely sturdy
Titanium stems for
the wishbone bearings, and optional Titanium accessories such as
caliper mounting studs. The finished item is hugely stiff yet
very light. The standard S2 bearing hub pack is bolted to the
upright with special bolts included in the kit, new Lotus OE
bearing hub packs can be supplied if required.
Installation
To attach these uprights to standard wishbones requires the
removal of the original outer ball joints and in their place a
steel insert is fitted. This insert then can be fitted with a
high quality spherical bearing.
If you are using our Full Race T45 wishbone kit, this is not
necessary as these bolt straight onto the Ti stems fitted to the
uprights.
To compliment the upright, the
cooling carbon pack
can be fitted as mentioned above. On the front, this comprises
two carbon parts per upright. A high temperature carbon disc is
bolted to the outside face of the upright, which will seal the
eye of the vented disc when it is fitted onto the hub. On the
inner face of the upright, a carbon ‘ball’ is bolted which can
be connected to a 2” ID silicon brake duct hose (not supplied in
the kit). This then allows cold air form a brake duct to be
pumped into the inside of the upright spool. On the rear, the
idea is the same, but the carbon ‘ball’ has a hole in the centre
which allows the CV joint to pass through, which also then
benefits from cooling air.
We have personally tested this kit in the
Britcar 6 hour
this year and the improvement in geometry removed some of the
peculiar handling we were having before with the original
uprights. We also benefitted from the
improved disc cooling
and a
reduction in the un-sprung mass.
Weights
These are all-up weights of the complete assemblies:
• Nitron front Race upright 1.096 kg
• Standard Lotus front upright 2.6 kg
• Nitron rear Race upright 1.706 kg
• Standard Lotus rear upright 2.6 kg