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False Advertising HSV

A HSV GTS with a whole lot more power than its number plates suggest...

Words by Michael Knowling, Pix by Julian Edgar

Click on pics to view larger images

At a glance...

  • Rare HSV VT2 GTS
  • 383ci stroker
  • US-sourced aftermarket heads
  • Harrop eight-throttle manifold
  • 330kW at the wheels
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You know you can’t always believe what you read, right? Well, this is an example that might prove embarrassing if you’re one of those people who are easily drawn along. Those 300KWS number plates fitted on Geoff X’s VT Series 2 HSV are truly deceptive – yes, it was once rated at 300kW but now there’s closer to 500kW at the flywheel...

But you’ll find out about that only when the lights change!

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Geoff stepped into this rare (one of 100 built) HSV GTS while most people were still choking at the mere thought of a 300kW Aussie sedan. The GTS set a new standard in Australian muscle cars with its C4B engine boasting CNC ported heads, improved cam and valves, higher compression, 78mm throttle body, MAF-less air intake, low restriction exhaust and a tune optimised for premium unleaded. Factory output is a massive 300kW at 6000 rpm. Give the car a six-speed ‘box, short ratio LSD, big brakes, HSV sports suspension, 18 inch wheels and some bling and you’ve got a real winner. Geoff thought so too. He was happy to keep the car stock for three years before he thought some more power was needed. Three-hundred kilowatts is a fair ol’ serve after all...

The first tweaks were a custom exhaust and ECU remap – a pretty standard power-up for anyone with a LS1. These mods raised power from 220kW to around 245kW at the wheels (a gain of more than ten percent). Geoff enjoyed the extra poke and the enhanced exhaust note for another year before he decided to dig deep into his pockets for the comprehensive power-up he felt the car deserved.

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Geoff isn’t a fan of forced induction so he decided to take the stroker route to achieve big power. PowerTorque in Brisbane answered the call with a 383ci (6.3-litre) Eagle stroker kit teamed with CP forged pistons providing a compression ratio of 10.8:1. This is about as high as you’d want to go in a street car running pump fuel.

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Initially, the engine was reassembled with the standard CNC ported C4B heads working in conjunction with a Comp camshaft. The standard C4B intake system was also left in place. Recognising the potential for significantly greater power, the exhaust system was again revised with Pacemaker Tri-Y headers and a twin 3 inch Di Filippo system.

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This mechanical configuration provided monumentally improved power and torque but when the Harrop eight-throttle induction system was released, well, Geoff just had to have one. Interestingly, this magnificent induction system (which breathes through twin foam air filters) didn’t deliver much extra top-end but the improvement in idle quality and overall driveability were more than welcome. At this point, it was obvious that the standard C4B heads (although improved over the standard LS1 items) were holding back power. Geoff then splurged AUD$5000 for a pair of AFR Mongoose heads from the ‘States. Fitment of the new heads – along with PSI valve sprints, titanium retainers and bigger valves – gave an improvement of around 30kW at the wheels. Nothing to be sneezed at.

In its current tune, this beastie rolls out 330kW at the wheels which equates to almost 500kW at the flywheel. With an extra 200kW over what’s quoted on the number plates, Geoff might soon find himself charged with false advertising...

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The GTS come factory fitted with a six-speed T56 ‘box that’s plenty strong so there has been no need for major driveline work. The only changes are an upgrade clutch and Ripshifter. The rear-end retains the services of the factory Hydratrak 3.91:1 LSD. Brakes and suspension also remain standard. Fortunately, the GTS comes with 343mm ventilated and cross drilled discs with big 4-pot calipers at the front and 315 ventilated and cross drilled discs with 4-pot calipers at the rear. Springs and dampers are tuned by HSV and note that the GTS was the first Holden-based vehicle to receive rear toe control links (which improve stability and tyre longevity). Geoff runs his car on top dollar Pirelli P Zero Corsa rubbers, which you don’t want to see wearing at an accelerated rate...

Not long after our photo shoot, Geoff had the opportunity to test the car at the drags – not that he’s really into that sort of thing, he just wanted to give it a bash. His best time was a 12.9 at 115 mph with a gentle launch and pretty leisurely gear changes. Geoff points out that the car is his weekend pride and joy – he doesn’t like flogging it to death.

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It’s obvious that Geoff keeps the car immaculately presented at all times and it’s no surprise that he has it professionally detailed every fortnight - spot a ding or paint scuff on this machine and win a prize! The body and interior remain 100 percent standard GTS fare. The only change indoors is the fitment of a DVD head unit and Lansa front splits.

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Geoff is one of the few feature car owners we’ve come across who is completely happy with their modified ride. It’s comfortable, damn quick, utterly reliable and – amazingly – it achieves better fuel consumption than standard. Can’t complain about that! And what are his views on the latest and greatest Holden/HSV vehicles with LS2 grunt? Well, they look pretty schmick but don’t expect Geoff to be making the switch. He quite rightly points out that the VT Series 2 GTS was the first in the current era of HSV supercars – the last thing he wants to do is become like those teary ex-Falcon GTHO owners who wished they never sold...

For now, he’s more than content sucking people in with those deceptive number plates!


PowerTorque +61 7 3881 2379

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