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3500hp twin-turbo Holden HQ

By Mark Arblaster | Photos: Chris Thorogood, 26 Jun 2019 Features

3500hp twin-turbo Holden HQ

Daniel Szabolics’s head-kicking, 3500hp HQ could be the first six-second car on Street Machine Drag Challenge

WE’RE always excited by a new build, and Daniel Szabolics’ twin-turbo 632ci HQ sedan is no exception. The car has the potential to crank out upwards of 3500hp and run into the six-second zone on a 275 radial, and Daniel has his sights set on Street Machine Drag Challenge 2019.

This article on Daniel's HQ was first published in the June 2019 issue of Street Machine

Holden HQ rearDaniel explains the journey that led to his HQ’s ballistic Dandy Engines-built twin-turbo powerplant. “I initially had my heart set on a 632 with an F3R ProCharger,” he says. “We made some blower brackets to get the ProCharger down low rather than have anything bulging out of the bonnet, and all that seemed like a good idea. Then I contemplated a front-mount crank drive, and after unsuccessfully trying to work out how that stuff would fit in the front of an HQ, I decided to go the twin-turbo path.

Read next: 1300hp blown 1974 Holden HQ sedan - KRANKY

Holden HQ boot“I had been watching the Pro Street scene for some time and had been really impressed with the success of the Dandy Engines team, especially Frank Marchese’s XW – wow, sevens on a 275 radial in a 3600lb car! I could tell they really knew what they were doing, so I gave him a call. I told Frank all I wanted was a cool streeter that would run a seven-second pass; Frank laughed and said we could do that with a plug lead hanging off!”

Daniel has owned the HQ for years, part of a collection of cool rides he has accumulated. “I always liked hatchback Toranas, HQs and HK coupes,” he says. “I was lucky enough to have bought all three back in the day when they were not worth anything. In the case of the HQ, it was a local car from here in Albury-Wodonga. It’s been in the build for the past eight years, but I guess I’m my own worst enemy as I keep changing my plans.”

But the plans for the build are now set in stone. The boys from Dandy have completed the monster mill and it’s down to minor fabrication work and finishing touches to get it up and running.

Holden HQ engine bay“Initially I was a little concerned about the size of the engine,” says Dandy’s Frank Marchese. “This thing is going to make a ton of power and it’s going to hit a 275 really hard in the first 60 feet. Daniel already had a lot of the parts so we really wanted to go with what he had. In this case we have ended up with a 4.6-inch-bore Dart Big M block with a 4.75-inch-stroke Callies Magnum crank, Oliver rods and Diamond pistons, and with AFR cylinder heads.

“For this build we have gone with a set of Precision Pro Mod 94 turbos with Precision wastegates and blow-off valve. In an engine that was 100ci smaller we have made over 3000hp, so this combination is really as nasty as you will ever get in a street car.

“We are going to give it a shot with this combination, but we are prepared to build a smaller short motor, somewhere around 500 to 530 cubes, if this thing is too brutal.”

Holden HQThe mill uses a Peterson R4 externally belt-driven oil pump with a Jesel belt drive on the cam and T&D 1.75:1-ratio rockers, with cam specs around 275 on the intake, 288 on the exhaust and 114 lobe centre.

Fuel supply is from a rear tank to a Weldon belt-driven 16-gallon pump and a Bosch 044 primer pump for starting. The combination will run on E85 on the street and alcohol at the track.

Watch next: 1350hp Twin-turbo LS-powered Holden HQ on the dyno

Holden HQ interiorEach runner of the billet CNC-machined Plazmaman intake manifold is fitted with a 250lb Siemens injector and a monstrous 700lb Billet Atomizer injector controlled by a Weldon regulator. Just to put the level of this build into perspective, the manifold runs around $7000 and a set of those 700lb injectors are roughly $5K!

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