What is it?
If you thought the Vauxhall VXR8 was a bit special, you should see this. It’s the Holden Special Vehicles W427.
The HSV W427 has been partly built to commemorate the 20th anniversary of HSV cars (the 1988 Commodore Group A SV homologation special was the first).
But the HSV W427 has also been built because Australia’s Holden Special Vehicles, owned by Tom Walkinshaw, has been able to get its hands on some 7.0-litre Corvette Z06 engines. Holden reckons the current-generation Commodore can handle the LS3 V8’s 503bhp and 472lb ft.
The W427 (W for Walkinshaw, 427 for cubic inches) is quite a serious installation job by HSV standards.
Usually Holden’s Adelaide factory fits the powerplants on the regular line and leaves HSV’s Melbourne facility to finish the job, but here the 7.0-litre engines are delivered straight to HSV in crates from the US.
So in HSV’s plant the factory motor has to come out before the new one is fitted, along with a dry sump, new intake manifold, HSV-specific ignition mapping an active-valve exhaust.
There are some pretty serious suspension changes, too, including magnetic dampers and, by HSV’s affordable-brute standards, a serious price of around $155,000 (about £70,000, depending on the exchange rate).
What’s it like?
Anyone who’s a fan of the VXR8 (and that includes me) will love this car. At idle the valve in the active exhaust is open, so it woofles and burbles like a 7.0-litre V8 ought to. The drivetrain is slick, with a manageable clutch and a new, stronger but slicker-shifting six-speed gearbox.
And by crikey is it fast. HSV claims 0-62mph in 4.7sec, which is quick in itself, but it would probably go even faster with a quicker gearbox and more traction.
The engine is astoundingly flexible, though. This is a very torquey motor, yet it also revs cleanly out to 7000rpm, past peak power at 6500rpm. Despite the extra capacity over other HSVs it feels no more unbalanced.
Because of the extent of the changes to the suspension, the W427 feels much tighter than a regular VXR8, with sharper, more accurate steering and better-controlled damping, with no massive drop in ride quality.
There’s a ‘track’ mode to the damping, too, but it’s good enough to use even on lumpy roads. The W427 is a bit fidgety with it on, but it steers and handles with even more precision.
And of course, the W427 has a beefy limited-slip differential. So, of course, it pulls big, smokey skids to Olympic standards.
Should I buy one?
I’m afraid that, unless you live in Australia, you can’t. They’re all destined for HSV-mad enthusiasts down under. The W427 is expensive, but still significantly undercuts M5s and the like in Australia, so all 90 scheduled to be built in 2008 sold easily. Production is limited to 427 units overall.
HSV says none will come to the UK, which is a shame. But give them a call. They could probably be persuaded.