He explains: ‘It proved to be the best donor car, due to the
stiffening in the soft-top chassis, which then avoids the need for more complex
engineering of the roof to take more strain, as well as the ride quality and
the super-touring character of the engine and drivetrain. Then there’s the
advice and expertise being just down the road at Jaguar too, and a substructure
made of aluminium castings, which makes bonding the body on top simpler.’
5000cc 32v V8
supercharged engine
I like the lack of hubris in Brown’s approach to the way the
car drives. He hasn’t tried to fettle the engine or uprate the chassis, because
buyers of this car aren’t choosing it for ultimate performance and handling,
and he says the XKR does a great job already of being relaxed but fast in its
own right. So the measured, calm steering is still there, the blowing roar of
the 500bhp supercharged engine (I think it might be a touch louder in the
Speed-back’s cabin) and the smooth ride remain.
A pronounced whistle around the driver’s side A-pillar will
need sorting, but otherwise it’s a pleasantly fast cruiser, and because it is
only about 40kg heavier than the ag XKR, no major bolstering of the suspension
has been needed.
Speedback GT 2014
back light
The cabin isn’t finished, but it’s not without promise.
Fields of leather have been stitched by the craftsmen and women who do JLR’s
bespoke stuff and it is perfect, lavishly laid across almost everything. Again,
this is the result of old-school know-how and modern techniques. The reason the
finish is so good is that the plastic substrates are 3D printed from a digital
template, which means that the fi t onto the underlying architecture is
millimeter perfect and allowing the thick covering to drape perfectly over.
Chrome exhausts on
Speedback
Brown explains why this has been so important: ‘Before the
advent of this technology, it would have been completely impossible, or at
least inordinately costly, to produce these small numbers to a mass-production,
zero-tolerance standard.’
And while a door substrate might seem a fairly proletarian
problem in a car of this cost, it’s exactly the sort of thing that is
manufactured poorly and installed wonkily in low-run cars that buyers
instinctively feel when they are in the cabin. The cabin groans, literally and
metaphorically, with millionaire cowhide but there are other areas that can
politely be called a work in progress. The basic electronic architecture is
taken from the XKR but with individually made new metal switchgear, and that’s
less successful.
The seat controls and door pulls have a habit of sticking
and there’s a recalcitrance to the buttons for other functions such as driving
modes and access to the infotainment.
But this is what a pre-production car is all about, finding
what works and doesn’t, and usually these kinds of problems (and the one where
the art deco speedo needle is properly retro because it lags the Jaguar digital
one by about 5mph) are encountered on test tracks and factories, far from
prying eyes, and surrounded by numerous engineers. Not in a one-off deal like
this though. Every mile is a test mile.
You could criticise the Speedback’s looks for being a
pastiche of things long since gone, a mock-Tudor mansion on wheels, but that
would be doing it a disservice because many of the engineering skills, mainly
in the Midlands, that have been brought to bear on this car are craftsmanship
of the very highest quality, and you should never denigrate the use of those.
Brown’s skill has been weaving the various firms, craftsmen and women into the
project.
