Still don’t know how I ended up with twin turbos,” says Gary Hayward of his ZC Fairlane. “For years it was just my work car and I’d actually decided to sell it. We had it sold but we took it for one last drive and that changed our minds.”

First published in the February 2007 issue of Street Machine

That ‘we’ includes Kylie, then Gary’s girlfriend and now his wife. Having decided to keep the ZC, the couple bit the bullet and realised it was time to give it the full street machine treatment.

The first step was to fit some decent rear rubber, so the car was taken to Thunderoad Performance for a set of tubs and a new rear end set-up, including Koni shocks and a sheet-metal nine-inch housing, packed with 3.9:1 gears and a set of Romac 35-spline billet axles.

That gave the Fairlane a serious stance but it only had a stock 302 Windsor for propulsion.

“We talked about lots of different engine combinations but once we started with the twin-turbo idea, it was hard to stop,” he says.

That’s for sure! SLEEPA — the plates kinda give the game away — is pretty much the hamburger with the lot when it comes to street turbo V8 combinations. There’s some pretty trick gear tucked discreetly under the bonnet. At the heart of the project is a 347ci Windsor, built by Queensland drag racer Gerry Cooper. Gerry cooked up a stout little stroker based on a ’96 5.0-litre block, complete with roller cam and 8.3:1 CP forged pistons.

With a project like this, though, the engine combo is just along for the ride; the bolt-on parts are what make or break it come dyno-time.

The turbos are T04 Garretts, matched to a couple of Turbosmart 45mm external wastegates. The huffers are fed hot exhaust gases by a pair of custom extractors that were fabricated from steampipe by the team at Thunderoad. Cooling the compressed charge is a water-to-air intercooler. While these units can be devastatingly effective at reducing inlet temps, the size and complexity of the components involved can make them a headache to fit in the engine bay, and in this case, space was already at a premium.

“Once we had the engine mocked up in the bay, it was pretty clear we were going to run out of room in there for a few things,” Gary says. “The brake booster went under the right-hand guard to make room for the extractors, and once the radiator went in, there was no room for a water pump.”

We talked about lots of different combinations but once we started with the twin- turbo idea, it was hard to stop

That meant fitting an electric Davies Craig unit, which in turn meant relocating the battery to the boot to make space for the new pump.

The intercooler problem was solved with a pair of PWR barrel-style ’coolers, one located under each front guard, behind the headlight. The 20-litre water tank joined the battery in the boot.

Unlike some water-to-air systems, Gary’s car runs a heat exchanger behind the grille for maximum efficiency. The cooled charge heads via a pair of 80mm throttlebodies, to a custom low-line plenum and finally to a Victor Snr inlet manifold.

Feeding fuel to the beast is a Mallory pump and a custom fuel-rail that supplies eight 96lb injectors. Sparks are generated by MSD gear, with the whole lot controlled by an Autronic SM2 ECU. It’s neither cheap nor simple but it is devastatingly effective. How does 500hp at the treads on 7psi and a conservative tune sound? There’s quite a bit more power still to be had but for now Gary is happy.

“The boys are always asking when I’m going to up it but any more power would really make it difficult to drive on the street. At the moment it’s perfect — the Powerglide tames it down a bit anyway.”

Of course, there’s a lot more to this car than just effortless, reliable power. For starters, those big, shapely panels are baby’s bum smooth and look a treat in the Narooma Blue duco. The colour was lifted from the AU Falcon catalogue and applied by Bodyline Smash. The interior is super-sanitary, with new leather added by the boys at Precise Trim. Gary went for a tidy, factory-style job with subtle ‘Sleepa’ logos embroidered on the backrests.

That done, it immediately became apparent to Gary that the factory dash had to go: “It just didn’t suit the car anymore. The rest of the car has a modern style to it.”

Precise dreamed up a sweet custom unit filled with Dakota Digital gauges and trimmed in matching leather. Other interior goodies include billet window winders, a B&M Pro Ratchet shifter and a Sony Xplode audio system featuring a roof-mounted DVD. All of which should keep anyone happy.

GARY & KYLIE HAYWARD
1970 ZC FORD FAIRLANE