Is this Australia’s
ultimate road-going LS1? Well, with the instant grunt of a 382ci stroker kit and
a magnificent Whipple forced induction set-up, it could well be.
The vehicle you’re looking at has been built by
Melbourne’s Starr Performance and
uses one of their early Whipple supercharger kits. The kit incorporates
a replacement intake manifold/adapter plate, a remote drive pulley arrangement,
remapped ECU, fuel pump voltage booster, cold air intake, 94mm throttle body,
water injection and an elegant water-to-air intercooler arrangement. Note that
the twin-screw blower employed in this vehicle is from the previous generation
of Whipples – it is slightly larger in volume than the current model.
With about 11 psi of boost in the standard kit configuration, you’d reckon
the resulting 400+ kilowatts would be enough for most people - but not if you’re
on a quest for
Australia’s
ultimate LS1.
The stock engine internals limit the amount of power achievable, so the LS1
was pulled apart for a suitably strong and low compression (8.9:1) rebuild. Of
course, this was the perfect time to make a few extra enhancements so a Lunati
382ci stroker kit found its way in! Yep, this baby now sweeps 6.3 litres!
The standard alloy heads were treated to a port’n’polish job and larger
diameter valves were inserted. A relatively mild camshaft was also slipped in
along with suitable springs, retainers and timing gear.
When the engine was first built, it was equipped with a set of 43lb/hr
injectors - as found in the off-the-shelf Starr blower kit. However, the rest of
the system is custom – there is a pair of in-tank pumps feeding a surge tank which supplies twin Bosch Motorsport pumps. An adjustable fuel pressure
regulator is also installed.
The ignition system remains standard, with the exception of aftermarket leads
and plugs.
The breathing capacity of a supercharged and stroked LS1 is pretty
monumental, so there were special efforts to ensure adequate exhaust gas flow.
The exhaust system kicks off with a set of custom-fabricated 1 7/8 inch short
primary extractors, which lead into a serious twin 3 inch system. High quality
cat converters and a total of four mufflers ensure the beast is seen but not
heard.
Now let’s talk power numbers; what does she make, mate?
Well, with everyday 98 RON fuel in the tank and up to 14 psi of boost, the
guys at Starr Performance have seen 425kW at the wheels. That equates to almost
600kW at the flywheel – disregard the conservative 550kW badges stuck on the
body. We’re also told there’s over 1000Nm of torque from around 2800 rpm...
Grrrrrr!
Initially, the car was built with the intention of regular club racing. This
being the case, a 7 litre baffled sump, remote oil filter and water-to-oil
cooler were installed to keep the engine running safely. An oil catch can has
also joined the band of under-bonnet accessories.
The standard Holden 6 speed gearbox has so far stood up to the punishment –
largely because the car isn’t fitted with slick tyres. Still, a dual-plate
clutch is currently in service. A KAAZ aftermarket LSD was destroyed not long
before out photo shoot and it was decided to try a stock Holden V8 LSD. No
problems so far.
Note that a Racelogic traction control system was installed, but the system
(which cuts fuel to certain cylinders) never worked to its potential with the
mega-power LS1.
Interestingly, the car started life as a 2000 Holden VX Executive so, of
course, a suspension and brake upgrade was essential.
The intended track work lead to installation of Koni double adjustable
dampers and motorsport-spec springs. Whiteline swaybars and a camber kit further
improved on-road feel.
And the brakes? Well, they’re nothing less than 6 pot AP front calipers and 4
pot AP rears. Front disc diameter is a whopping 380mm and street/race Pagid RS42
pads are employed.
Styling wise, the clean slate of the VX Executive body allowed fitment of the
desired spoiler and side skirt kit – a VX Series 1 HSV GTS arrangement. The rims
fitted at the time of our shoot are tasty 3 piece Simmons. Oh, and check out
those neat ‘550’ badges.
So far you may have noticed that we’ve dodged the issue of who owns the car.
Well, the original owner performed the ground-up rebuild, sold it to Neville
King (the owner at the time of photography) and it has recently been passed on
to an interstate owner. Before going to its latest owner, however, Neville made
a few changes to suit his application – namely, high speed cruising in the
Northern Territory...
“It did 270 km/h dead easy,” says Neville “but it was limited by its
gearing.” However, that’s probably not such a bad thing given the amount of
steering correction the VX required at that sort of speed. “At the end of the
day it’s still a tin box taxi...”
The suspension was made a bit more accommodating with the fitment of HSV
Clubsport springs. Huge 255 and 285 Pirelli P-Zero Rossos were also crammed
under the guards – the rear requiring mini tubs. The engine also received a
freshen up with a slightly wilder cam profile and larger injectors stirred into
the mix. Boost pressure was reduced slightly to prevent engine melt-down during
those sustained high-speed runs.
The existing club sprint spec interior was also replaced with a more liveable
leather trim, 6 stack CD sound system and a standard HSV steering wheel. Comfy.
Neville had great fun during his time with the VX, winning lots of trophies,
attracting lots of attention and, of course, barrelling through the countryside
at extremely high velocity. Yep, there are lots of fond memories but Neville’s
latest acquisition – a brand new Lamborghini Murcielago - kinda softens the
loss...
How does the Lambo compare to the tuned Commodore, you ask?
No comparison.
“The Lamborghini has electric spoilers and, from the ground up, it was built
to travel at high speed,” says Neville. And when Neville says it’s fast you know
its fast.
How does 335 km/h grab ya?!
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