Sienna - Short but sweet
After several years of intensive development, Sienna cars
finally got it’s Countach replica pretty well sorted out by early 1991.
Then, just as the future was looking bright, the company suddenly
folded.
As with most Countach replica’s, the Sienna was developed from an
earlier example of the breed. In this case it was the Prova, although
it is very likely that the Prova came from Venom etc., etc. A guy called
Alan Booth was the man responsible, and little could he have guessed
that, as he founded a business building up Prova’s for other people,
that he would end-up creating a car which some reckoned was better then
the original Countach! Alan Booth, a New Zealander, wandered over to the
UK for a holiday in 1986 and, instead of going home again, had become
involved in the kit car industry. He used to be a sheep farmer, so
obviously the next step in his career had to be making Italian replica
supercars. It’s what most New Zealand sheep farmers finish up doing
ultimately! Actually, he had also been involved in oil pipeline
technology, but after a few years of constant airports and relentless
pressure, he’d wanted to get into something with an element of pure fun
in it.
Alan had at the time never heard of the Lamborghini Countach, although
he was quite familiar with Lamborghini tractors. When he first came
face to face with a Countach, he was gobsmacked. Having got past that
reaction, the next stage was: "I must have one!".
At that time the Countach replica industry was in it’s infancy, and it
took all Alan’s engineering skills (and knowledge of sheep?) to
complete his first build, a Prova of course. Offering his services
through the kitcar press, an order or two materialised and premises
were taken on a run-down farm industrial estate at Ranmore Common, near
Dorking, Surrey. A show appearance brought more orders and suddenly
Sienna Cars was fully viable. Trouble was, Alan knew he could do better
then the Prova...
With funding provided by a wealthy customer, developement of the Sienna
Countach proper began. A new chassis, new body moulds, fully revised
suspension, an improved interior, easier production facilities – the
car got the lot. It also got a new home. Still very rural, and this
time on an old army storage depot at Sutton Veney, near Warminster,
Whiltshire.
Thousands of development hours, plenty more funding, further improved
moulds and much company restructuring later, and the car had matured
into something rather special. By spring 1991, with a small number of
kits already supplied, the Sienna Countach was receiving wide acclaim.
Which Kit? magazine was full of admiration:
‘The Sienna one of the worlds fastest, most exotic sports cars? Of
course. The car is an absolute credit to the whole kit car industry.
We’re happy to say that the Countach replica has truly arrived.’
Little could the magazine have predicted the brevity of the euphoria.
All in all, the Sienna Countach was a pretty serious piece of kit. The
exterior dimensions accurately replicated those of the real
Lamborghini, although inside there was more headroom and some 4” more
legroom. Powerplants were variable, although one of the favourites was
the 302CI Ford V8, with the smaller Rover V8 as another option, and the
occasional Chevrolet 350. The Renault V6, fitted with the Renault
gearbox wasn’t a bad option either: quite a good unit and quite
tunable.
An unusual engine at one time fitted to the demonstrator was a Cosworth
2-litre turbocharged Ford Pinto unit: However, it didn’t sound right or
feel right, so it was replaced by a Ford 302. At one stage, the Jaguar
V12 option was under development, but posed large problems – gearboxes
and all that. The Renault 30 unit, used in most Countach replica’s,
just wasn’t up to the job of coping with the V12’s creamy, limitless
power.
The chassis, made in-house, was an advanced multi-tubular spaceframe
with an integral roll-over bar. There were nice touches in it, such as
an extra bearing designed into the steering linkage for extra
smoothness and precision, and in the engine compartment a bolt-on brace
bar to make engine and gearbox removal easy. With new jigs, tolerances
were down to 0.5 mm, which was close enough for anybody.
Suspension was independent all round via double whishbones, coil-over
schock absorbers and Ford Scorpio hubs and uprights. The steering and a
full set of disc brakes were also Scorpio, all chosen on account of
their design quality and worldwide availability. There was no doubt
about the thought invested in the layout.
Wherever possible, computer aided design and laser cutting techniques
were used. The grilles around the car were a visible sign of this: they
were laser cut steel, powder coated. They were perfect, end of story.
The Sienna designed suspension parts were also laser cut, where they
weren’t castings. Where they were castings, there was some clever stuff
going on. Rose joints were used in the suspension. Aha! Might one
think, that means a horribly brutal ride, and they wear out in 10
minutes!
Well aware of that, Sienna enclosed the rose joints in rubber boots,
filled with grease to keep the grit out, and mounted bushes in the
castings to keep the ride civilised as well as gaining the precision
suspension provided by rose joints. All clever stuff!
The same blend of sharp handling and a reasonable ride was followed in
the shock absorbers, made by AVO for Sienna. The system was set up with
a corner weight facility, and with the adjustability inherent in the
rose joints and the shock absorbers, the suspension could be tuned to
suit pretty well anyone.
Turning to the nicely moulded body (with bonded in steel reinforcement
to increase upper body rigidity), there was curved, laminated, tined
glass throughout, provided by a local company. The windscreens
themselves were supplied by Triplex. The GRP bodywork was massively
solid: the front bonnet was hard to pick up by hand, and it was by no
means a big panel. The engine radiators, mounted behind your shoulders,
were large locally made items, very effective indeed. The twin fuel
tank fitted under the radiators were made in aluminium by Sienna,
filled with Explosave.
Arches, front spoiler and so on, were bolted on seperatly, like the
original car. Something that we never saw on any other Countach
replica. With as extra benefit that these items could easily be
replaced if damaged. Sienna even advertised with providing every
customer with a free front spoiler per year.
Laser cutting again reared it’s head: the tail reflectors were cut this
way, and they fitted perfectly. Likewise, the dashboard blanks,
available in plywood, steel, ally, veneer, anything you liked. What
would normally constitute literally a full day’s delicate work with
drilles and files, took the machine 0.92 seconds.
The car was intended very much to be a practical every day vehicle, and
the demonstrator was deliberatly used that way in order to make the
point. As well as being trashed around the place by every journo in the
world and by hundreds of potential buyers, it was used by Alan Booth as
an every day car for work shopping, and had no other attention other
than frequent washing. The engine bay was defenitly that from a working
car, and a noticeable advantage was accessability. While access will
never be easy in a car this shape, it wasn’t bad at all in the Sienna.
The luggage boots, one at each end, held a reasonable amount, and the
cabin was spacious., with lots of sprawling room particulary for the
passenger. The windows on the demo car were fixed, as interior cooling
was by an air conditioner fitted in the front boot. All smart stuff.
In action, the Sienna was equally smart. Clambering in was as akward as
with any Countach but at least the doors shut with precision. The dark
blue demo car’s cabin was laid out in original style and beautifully
trimmed in light grey leather. Though the seats needed adjusting for
the individual driver, the driving postion was basically spot-on and
the controls all well sited.
The menacing yet comfortably muted rumble from the 260 BHP Ford 302 V8
sounded great. At cruising speeds, the car was docile, the power unit
lazyliy comfortable; if you wanted to use a little more muscle on the
accelerator, the Sienna’s engine provided more muscle itself and urged
the great thundercar forwards. With the carburettor’s second choke
operative, the whole experience was exhilarating, the acceleration
relentless.
Ride was amazingly supple and comfortable for a car of such
proportions. Steering was pleasantly light yet retained the sort of
feel a supercar driver would need, it only became heavy at low speed.
With the gearshift accurate and precise and the braking pleasantly
progressive, the whole experience was a delight. The Sienna handled
with precision and gripped abundantly. A little old British kit car
performing like a classic Italian supercar? You bet!!
So, the car worked a treat. It was engineered superbly and blessed with
excellent quality body panels. A steady supply of kits was being made
at the Sutton Veney workshops and the future was looking bright.
Alan Booth has said he wanted to be known as the producer of the
world’s best Countach and he was getting there! Wheter you paid arounf
7500 gbp for a body/chassis kit or some 35k pounds for a fully
build car, you were getting something quite special too.
Problem was, you didn’t have very long in which to get it. From the
point when Which Kit? stated, in May 1991, that the Sienna was
‘probably the world’s best Countach replica’ the company only lasted
another few months. By early 1992, Sienna Cars had gone bust with
remarkably large debts. More confirmation of how financially dangerous
it was to attempt full-scale development and production of one very
complicated motor car. Even what was considered to be the best example
of the breed, had failed.
No more then 25 Sienna Countachs are believed to have left the factory,
in kit, semi-complete and turn-key forms. Not much of a total
considering the car’s quality and capabilities, but enough to ensure
that it won’t be forgotten.
Several of those 25 cars were shipped to various parts of the world and
appreciation will no doubt be the same in every language...
This article was published in the Which Kit? issue "Italian
sportscars".
With kind regards to Which Kit? for giving me permission to re-publish this article.
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