|
Price |
|
-- |
Production |
|
-- |
|
Engine |
1
liter V2 |
Weight |
728
lbs |
|
Aspiration |
natural |
Torque |
-- |
|
HP |
135
hp @ 9500 rpm |
HP/Weight |
5.4
lbs per hp |
|
HP/Liter |
135
hp per liter |
1/4 mile |
-- |
|
0-62 mph |
-- |
Top Speed |
-- |
(from SUB Press
Release) Set up by three
individuals Niki Smart, Jay Brett and Nick Mynott, SUB is a small
company in southern California that caters to clients who want
individual specialised vehicles. Their first vehicle, G1 a three
wheeler is an evolution of work done by Niki Smart years earlier on
the "One-up" that sat in London's' Millennium dome. G1 is a ground
up build, demonstrating the companys ability to produce, not just
one, but a series of fully functioning, innovatively packaged
vehicles that are road legal and that could be used in a day to day
scenario as well as being pushed hard on a track.
The original One-up
concept was 'An Engineering Aesthetic'. The project was about the
design beauty that purely engineered forms posses from their focus
on performance and efficiency. Smart looked a lot at castings and
fabricated suspension parts as well as WW2 battleships and
especially submarines. The idea was to be as minimal, without being
a bike: one seat, three wheels and a small engine. His original used
a 600cc Honda CBR located behind the driver. The resulting longer
wheelbase (2.7m) made for a rear biased weight distribution. The
track was 1.6m. While similar in concept, G1 makes use of a tight
packaged V-twin to reduce the wheelbase to 2.3m (same 1.6m track)
and to achieve a 50/50 weight distribution. The 50% on the rear
wheel and 25% on each front creates a dynamic, stable platform.
A major aspect of the
project was to design and build a vehicle with aesthetic appeal - a
single seat, lightweight, high performance machine ideal for quick
runs through canyons. The project was never about straight-line
speed or acceleration. More important was to create a vehicle that
handles predictably and controllably and is engaging and fun to
drive, while keeping the project within a manageable budget and time
frame.
So Why Three Wheels?
Even the sportiest of
cars on the market seem unnecessarily big with much unused volume
and weight. If you spend the vast sums of money that most exotic
performance cars cost, the last thing that you want when pursuing
the ultimate performance and efficiency is to put your friend next
to you, destroying your power to weight ratio and upsetting the
balance of the car. The idea of a single seater seems logical for
the ultimate in performance, even for the road.
In the automotive world,
the notion of using three wheels where four would do is often
received with wonder and mistrust. It's usually employed as a sales
pitch for vehicles that are generally odd or dubiously functional.
The discussions for and against are largely based on issues of
visual and dynamic stability, with the thinking that there is
something missing (usually the forth wheel). The aim of this project
was not only to build a vehicle that overcomes some of the stigmas
of three wheeled vehicles, but to surpass them and to exploit their
advantages in an exciting and desirable product.
Some points of the
project philosophy:
The cornerstone of
the project was to balance the weight of the engine with the
weight of the driver. The new package allows the vehicles to
achieve a weight distribution of 25% on each front wheel and 50%
on the rear.
A low centre of gravity and minimal polar moment of inertia
provide a stable but agile vehicle. Both recreational and sports
driving will benefit from its responsiveness and nimbleness and
it does not need power assisted steering or braking; so
improving feel and reducing component complexity.
Quick steering response is a by-product of reduced mass and
low polar moment of inertia, not on the number of wheels or how
they are configured. A typical three-wheeler is lighter and has
approximately 30% less polar moment than a comparable four wheel
design. The yaw response time is the time taken to reach
steady-state cornering after a quick steering input. This is
around 0.30 seconds for a softly sprung four-wheeler. Four wheel
sports cars will respond in about half that time. For a well
designed three-wheeler, it's as little as 0.10 seconds, which is
a third less than a high-performance four wheel car's typical
0.15 seconds.
A benefit of using three wheels is to qualify the vehicle as a
motorcycle and not a car, provided that the gross weight falls
under 1500lbs.
Consequently the vehicle does not have to comply with the
level of legislation that a car has to. This typically means
registration and road taxation.
As a motorcycle the vehicle can travel in the car pool lane on
freeways, even with just one person.
By using a 1000cc-motorcycle engine, efficiency is ensured (40
to 50mpg); because of the light, compact engine and gearbox, and
because the unit has been specifically designed to propel a
small mass as opposed to the engine and drive train in a
conventional car designed to propel an average mass of 3000lbs.
A major surprise is the
use of motorcycle tires. This was to get the right tire contact
patch area distribution as well as weight distribution, with minimum
tire frontal area and rolling resistance. As the Morgan three
wheeler demonstrated, you can attain high cornering speeds on narrow
tires. While it was easy to find a rear tire with the required
contact patch it was difficult to find front ones. However Avon
builds a tire for the cruising market where they have widened the
tire by splitting the conventional tire down the centre and added a
spacer. Available in a choice of widths, the Avons have the desired
contact patch and are designed and built for the weight of the
vehicle. They have low rolling resistance and frontal area, to aid
overall efficiency, and lend the vehicle a unique aesthetic quality.
The low centre of
gravity makes life easy for the suspension. Long double wishbones at
the front act through pushrods to inboard spring-shock units. At the
rear, twin trailing arms act through a pushrod to a transverse
mounted spring-shock unit. In such a light vehicle using rose joints
throughout and needle bearings in the rockers minimizes suspension
stiction. With a single tire at the rear, the front suspension
system controls all of the roll. To minimize pitch under
acceleration and braking, the front and rear geometry has a low,
central, instantaneous pitch centre. This geometry also increases
chain life by eliminating chain snatch.
Building the prototypes
Each individual brought
a complementary skill set to the project. Smart is a designer, and
fabricator whose rsum includes work on the Aston Martin Vantage
concept and the ultra-light weight Ariel Atom sports car. Brett's
background of Industrial design and his ten-year involvement in film
and automotive concept vehicle construction lends the project his
expertise in fabrication and program management. Mynott, a digital
modeller, has an extensive background in automotive, product design
and engineering and has worked on the construction of 6 concept and
race vehicles within the last 4 years. The combination produced the
expertise in design, modelling and build required for the project,
the overlapping skills creating an effective team.
Advanced 3D surfacing
software was used to model the entire car from the ground up. From
initial suspension geometry in wire frame to the completed wishbones
uprights and wheel arches, all modelled and animated through its
full range of motion. The computer enabled the team to design,
refine and simplify each component, reduce costs and simplify
assembly all before committing to production. In it's element as a
tool for building and checking interference, fit and assembly the
computer was used to speed production, reduce errors and produce a
higher quality at a reduced costs to the team. Throughout the build
phase, modifications were updated in data and the physical models
continually checked against the digital model to ensure tolerances
were met. Co-ordinate geometry machines and white light scans
ensured that all the space available was utilized to best effect,
giving a finished product that is tightly packaged, of minimum
weight and has a formula feel. Once surfaced and highlighted, the
body tools were CNC cut to produce highly accurate low cost
re-usable moulds. A complete cross section of tooling from plaster,
foam and clay to composite epoxy and even rapid prototype parts were
used. Composite parts were oven cured before being finished and
painted. Great importance was given to materials and finishes, from
the powder coated two piece custom made forged wheels to the black
phosphate finish of the steel bolts that hold the aluminium alloy
uprights together. Everything was given the same degree of
consideration and importance to ensure a coherent high quality
finish. The result is three fully functioning road legal custom
built vehicles that were delivered on time, on budget and to a very
high quality. Vehicles that have s ince driven over 1000 miles each
with only suspension and spring rates needed to be dialled in.
What's it like to drive?
The three cars are each
individually fitted to the customers with custom seats and floor
mounted pedals positioned to cater to their range in size; from 6
foot 8inches tall, to 5 foot 10 inches. The car uses a modified
motorcycle wiring loom and the gauge pack is carried through as
well, with everything functioning including the fuel level meter.
The indicators and lights are positioned around the gauge pack
within easy fingertip reach without having to take our hands off the
wheel. Each car is fitted with a four point anti-submarining harness
and uses a cut off Momo steering wheel for better gauge visibility.
The cockpit walls are high giving the formula car feel while rear
visibility is good due to the positioning of the mirrors. The gear
stick is mounted close to the steering wheel on the firewall that
separates the driver from the engine which maintains the 6 speed
sequential box form the TL1000R. The steering is quick with one
complete turn for lock to lock. The brakes are strong and
progressive giving good feedback. Driving on the road you are
smaller than most cars and much lower to the ground. You feel like a
race car driver because it has super bike-like speed and formula car
handling. The ability to see the wheels further enhances the formula
feel of the vehicle with the ability to place the wheels right on
the curbs through corners. It all combines to create an unbelievably
fun and unique experience.
Specification
Vehicle
Dimensions
Overal Length 3200mm / 125"
Overall Width 1760mm / 69"
Overall Height 1000mm / 39"
Weight 330kg / 86.6"
Track 1600mm / 63"
Weight Distribution 50/50 (50% rear 25% on each front
wheel)
Chassis
Tubular spaceframe contruction with aluminum and composite
bulkheads.
Predominantly 16SWG Mild Steel DOM (Drawn over Mandel) seemless
tube.
TIG welded.
Suspension
Front:
Double unequal length wishbones
Fabricated from 16 SWG DOM aero tub.
Fully adjustable rodends inboard and outboard.
Pushrod activated inboard suspension
Penske custom shock absorbers
T-bar type adjustable anti-roll bar
Rear:
Single sided arrangement. Upper and lower trailing arms.
Pushrod activated inboard suspension.
Penske custom shock absorber.
Adjustable camber and toe.
Steering
Rack and Pinion
1 turn lock to lock
Adjustable rodend steering arms
250mm Mono Suede Steering Wheel. Open top for better view of
intruments.
Quick release mount for ease of ingress and (when you remembe
to take it off, Mark) egress.
Seating
Epoxy composite construction.
5-point quick release harness
Suzuki Instrumentation.
Braking
Adjustable floor mounted aluminum pedal box
Cable operated throttle
Twin master cylinder front/rear brake pedal with balance bar.
Hydraulic clutch
Stainless Steel braided lines throughout.
Brake components common on all corners.
Wilwood 350mm/12" Single cross drilled discs
Two piston billet calipers
Custom Mounting Bells
Wheels
Two piece forged aluminum 18 x 5.5" front 18 x 6.5" rear.
Tyres
Front: Avon AM23's 180/55R 18
Rear: Avon AM23's 200/50R 18
Engine
Suzuki 996 cc 4-stroke liquid-colled 90 V-twin, DOHC, 8 valves,
135hp (98.6 kW) / 9500rpm
105 Nm / 7500rpm
Electronic Dual-Stage Fuel Injection - 52mm throttle bodies
Aluminum head block gearbox and sump
6-speed sequential grearbox
No reverse as yet. Park uphill or get a push.
Chain driven to rear wheel via a twin chain arrangement through
a jack shaft
allowing mounting for e-brake and in future a reverse gear.
Also easy adjustment of gear ratios.
Induction
Ram air effect bespoke airbox with panel filter.
Exhaust
Stainless steel tuned length (for torque, not necessarily power)
primaries
2 into 1 merg collector.
6" diameter single silencer. Loud pipes saves lives so they say.
Cooling
Increased volume aluminum radiator with electric fan
Silicone hoses
Fuel Cell
Epoxy composite
Capacity 7.5 US gal
More images and information at
www.sub3wheeler.com
