Blown LQ9-powered 2004 HSV GTO

HSV's GTO coupe was always a looker, but we wish they were all built like Robert Guljas's awesome blown example!

Photographers: Chris Thorogood

ONE of the most common lies we street machiners tell ourselves boils down to one simple sentence: “I’ll just give it a quick tidy-up.”

While it looks a million bucks now, Robert Guljas’s epic blown 2004 HSV GTO started off as a low-kay, but tatty, stocker. “The guy I bought it off used it every day, so it had a few scratches here and there,” Robert says. “It was just well-used, but it only had 120,000km, and I love these Monaros.”

This article was first published in the May 2020 issue of Street Machine

Behind the motor is a Powerglide and 4000rpm converter, while the 3.75-geared Pro9 9in features heavy-duty hardware like 35-spline axles to hold the blown LS grunt

Holden’s third-generation Monaro, coded CV8, was a hit from the time the top-secret VT Commodore Coupe concept broke cover at the 1998 Sydney Motor Show. The bodykit-clad HSV GTO and GTS coupes ramped the horn-meter up and were pegged as future classics almost from the time they were new, though this didn’t stop Robert stripping his new toy.

“I pulled the car apart at home with my two sons to give it a coat of paint,” he says. “Once we pulled it apart, things got out of hand, so we decided to get it done in time for Summernats.”

The GTO sports Pedders coil-overs up front with air suspension struts out back for a slammed stance, while Harrop six-pot and four-pot brakes live at the front and rear ends, respectively. The entire wiring loom was redone and tucked out of sight, as were the brake lines

Canberra’s annual Festival of Grunt is a common deadline for the builds of many cars, but what made Robert’s situation a little stickier was that he was starting his project in May. This left him only seven months to get the car finished, running and ready to be judged among Australia’s best modified cars.

“I changed the motor to the blown one, which I had in the build already for an HG Premier I was building at the time, and then we decided we needed to mini-tub the rear end,” he sighs.

While we love the vision of a dirty great blower poking through a bonnet, others are less enthusiastic about such shenanigans and Robert has already taken them into consideration. “Shane at Southern Rod & Custom made me a 6in aluminium reverse-cowl bonnet so I can put that on for street use, just so I don’t get pinged,” he says

While the 255kW, 5.7-litre LS1 the HSV GTOs scored new was no slouch in its day, the new motor is a far more serious piece of kit, as it is based on an LQ9 iron 6.0-litre block – one of the most desirable factory LS-based engines to build upon.

With the rising appreciation for modern Monaros, Robert thought he might incur the wrath of the ‘wrecked a classic’ flops. “I thought I might have copped some grief for it, but I haven’t so far,” he says

Mick Cleary from Hazardous Motorsports took the job of installing a Lunati four-inch crank and CP Bullet pistons to push displacement from 364ci up to 408ci, with Scat rods, Carrillo rings, Morel tie-bar lifters and a solid-roller cam. One of the key appealing points of the LQ9 over the 4.8- and 5.3-litre iron LS motors is that the bore is large enough to bolt on deep-breathing rectangle-port heads, and Robert did just that with a pair of CNC-ported PRC LS3 castings. These have been topped with a billet-case 6/71 supercharger from Joe Blo Speed Shop, topped with a Joe Blo slimline billet hat set up to run EFI.

“I am building a tubbed HG Premier and was going to put this engine in that,” says Robert of the GTO’s blown 408ci LQ9. “I’ve still got the HG and I’ll do that slowly, as I’ve also got a ’67 Impala coupe being built up at Southern Rod & Custom that will run a twin-turbo 502ci big-block built by Frank at Dandy Engines”

“I bought the engine off one of the guys who works for me,” explains Robert. “It was set up as a turbo engine, so it has been built for boost, but it was all brand new. I bought the manifold and supercharger set-up from Joe Blo and put that on. It’s yet to go on the dyno for a final power run, but we’re hoping to make 1000rwhp when it does.”

Holden’s pre-VE independent rear end is renowned for its less-than-optimal geometry, so Robert got the cutting discs out and liberated enough real estate under the GTO’s curvaceous bum to squeeze a fat 22×11-inch Simmons FR wheel.

A FuelTech FT550 runs the engine, which drinks boost-friendly E85 juice and expels gases out a twin 3in exhaust system

“Jason Thomas and I worked on the mini-tub job every night after work while Dave Dearing metal-finished the body,” Robert says.

“I had John Long fab up one of his Pro9 four-link rear ends with a nine-inch diff, which we also installed. My son Jeremy was in charge of engine bay smoothing, and, once all the metalwork was done, I put it on a rotisserie to sandblast the floor for paint.”

As a qualified painter and owner of Bannockburn Panel Repairs, Robert was in the box seat to coat his car in a killer colour, and his choice is bang on-point with the industrial-hued trends of late.

“I always like to build different cars and have a point of difference that stands out from the rest,” he says. “Every time I drove past a new Audi that was grey with the black wheels, I loved it, so I sprayed out a bunch of versions of the different greys used by car manufacturers. In the end I decided I needed to mix up my own version of that Audi grey, and I added a Xirallic pearl to it, so it really sparkles in the sun. I took the car to work and with the help of my head painter, James, we prepped the car for paint, which I laid down.”

Option Auto Interiors went through the interior to bring it up to an Elite level, using Alcantara and leather for a classy finish. A FuelTech display replaces the stock gauges, while a B&M Stealth shifter is used for picking gear ratios, and tunes are supplied by an Alpine stereo

Robert debuted the HSV at Summernats 33, landing in the Top 60 Elite and scoring the High Impact Award, then backing this up at PPG Showcars Melbourne with Top Street Machine. While he isn’t quite done with the show circuit yet, he’s already keen to hit the strip.

Frank Marchese will retune it and we’ll probably take it to Sydney and run it to see what it does,” he says. “I’ve driven it a little bit and it feels awesome, but because I went so far and painted underneath, I have to keep it nice for a bit.

“I haven’t thought about what time I’d like, as I’ve never had a car I’ve run at the track. Some guys are saying it could go nines, so maybe I’ll need to get it ’caged. I’d be rapt with a 10!”

2004 HSV GTO

Paint: Standox custom mix

Brand: GM LQ9
Capacity: 408ci
Induction: Joe Blo EFI hat
ECU: FuelTech FT550
Blower: Joe Blo 6/71
Heads: PRC LS3 CNC-ported
Camshaft: Solid-roller
Conrods: Scat
Pistons: CP Bullet
Crank: Lunati 4in
Oil system: Melling pump
Fuel system: Aeromotive pump
Cooling: Aussie Desert Cooler radiator
Exhaust: Pacemaker four-into-one headers, dual 3in exhaust
Ignition: MSD coils

Gearbox: Powerglide
Converter: 4000rpm
Diff: Pro9 fabricated 9in, 35-spline axles, 3.75:1 ratio

Front: Pedders coil-overs, electric power steering
Rear: Air Ride air suspension, Pro9 four-link, mini-tubs
Brakes: Harrop six-piston calipers and 385mm discs (f), Harrop four-piston calipers and 345mm discs (r)
Master cylinder: Stock

Rims: Simmons FR20 20×8.5 (f), Simmons FR22 22×11 (r)
Rubber: 245/35 (f), 295/35 (r)

All our wives for putting up with the build, and especially my wife Mel and sons Jeremy and Thomas; Jason Thomas; Dave Dearing; James Isaacs; Marcus and Matt from Speed Pro