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Supercharged L98-powered 1977 Holden LX SS Torana

By Ben Hosking - Story & Photos, 06 Feb 2020 Features

Supercharged L98-powered 1977 Holden LX SS Torana

An Aussie classic cops a 600rwhp supercharged makeover for the 21st century without losing any of its 70s identity

LIFE is full of ‘what ifs’. The imagination can run wild with the possibilities of what might have been had circumstances been different at any point in history. What if the 1970s oil crisis or the ‘Supercar Scare’ had never happened – what would the cars we drive today look like? What if GM’s 1990s EV1 electric car hadn’t been scuppered by Big Oil? What if Hitler had won WWII?

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

Holden Torana LX

Or, on a smaller scale, what if Holden could have had access to 21st-century engine design, sophisticated fuel management systems and satellites in the 1970s? Muss Ayri’s LX SS hatch could well be the answer to that particular question, although we doubt that was on his mind when he first spied the LX in a friend’s shed.

Read next: LSX-powered 1975 Holden LX Torana SL/R 5000

Holden LX Torana SS

What graces this page is a restomod in the truest sense. The genuine SS hatch retains its muscle car aesthetic right down to the PPG A9X white paint with blackouts and matching flares. But underneath lives a modern, blown, EFI heart complete with fly-by-wire, and inside you’ll find modern conveniences like GPS speedo and high-spec car audio wrapped in period-style clothes. It’s the perfect hybrid to make both the old-school crowd and the more forward-thinking chaps smile.

Read next: Twin-turbo LS-powered 1977 Holden LX Torana hatch

Holden LX Torana SS side

“I find most of my cars through friends,” 42-year-old Muss says. “I just saw the car sitting there in his shed and jumped on it. It was in pieces – there were parts everywhere.”

Muss is no stranger to building cars. He laughs when we ask how many he has built over the years. “I’ve had hundreds, man! People often have to remind me about the cars I’ve had.”

Read next: Chev 350-powered genuine Holden Torana SS hatch

Holden Torana LX SS hatch rear

Where many seem to stay loyal to a particular make or model, Muss says that he’s actually changed sides over recent years, having built a long line of 1970s Falcons in his time. These days, he’s all about the Torana. “I was a Ford guy all my life, but about five years ago I just decided I wasn’t touching them anymore,” he says. “I recently sold another LX hatch that had a twin-turbo LS in it, running an 8.1sec quarter at 171mph.”

Holden Torana LX SS wheel

A set of 15x10 Weld AlumaStars were squeezed under the bum of the hatchback, wrapped in 275-wide ET Streets

Indeed, this latest SS hatch was also destined to be powered by a twin-turbo combo. However, Muss ultimately decided against it, considering the holes he would have had to make in the genuine SS sheet metal. Instead, a chat to the guys at Russo Performance had Muss sold on the idea of the Magnuson Heartbeat 2300 supercharger kit.

Holden LX Tprana SS

Muss says he loves this view of the LX, which boasts a Curley’s IFS front end with Viking coil-overs, and those ceramic-coated, custom-made 17/8in headers that flow into a matching twin 3in system out back

In addition to simply looking sexy, the Heartbeat pump has proven itself capable and reliable in all manner of applications, from stockers to race cars – rated ‘safe’ by Magnuson up to 17psi and boasting cooler intake temps than some of its competition. Just the thing for a weekend warrior that needs to behave when necessary but light ’em up for the boys on demand.

Holden Torana LX SS hatch exhaust

The 9in rear end houses a set of tall 3.2:1 gears and a Truetrac centre, turning a pair of 35-spline Mark Williams axles – which is a good move considering the punishment Muss says he dishes out with the right foot

Russo bolted the blower onto a lightly modded six-litre GM L98 that uses its factory rotating assembly – albeit reinforced with ARP fasteners – and fettled the intake and fuel systems with a Russo-spec cam and lifters, Bosch injectors and pump. The combo, including the original fly-by-wire throttle, is controlled by the factory ECU and coils. “The Russo guys don’t seem to bother with mods that aren’t going to provide decent power gains,” Muss says of the OE-spec throttle. “They just told me not to worry about putting anything bigger on there.”

Holden Torana LX SS hatch engine bay

With a clean, symmetrical installation of the custom side tanks and monochromatic colour scheme, the blown L98 looks right at home in the LX engine bay. Muss says the combo is making over 600rwhp on 12psi and PULP on the stock-bottom LS and will fry the rear bags in top gear with minimal fuss

It would seem that Russo is onto something there, with the LX making more than 600hp at the treads at just 12psi on 98RON. A switch to E85 (which the car is set up for) would see that figure rise by around another 100hp – but Muss says he just doesn’t need it. Plus, PULP is easier to find when out cruising.

Holden Torana LX SS hatch engine bay

The L98 and the TH400 that is bolted to it are cradled by a Curley’s tubular IFS front end that uses Viking coil-overs. “It was the first time I used the Curley’s front end,” Muss says. “It feels comfortable. There are no knocks or rattles. Nothing shakes. You don’t even realise you’ve got something big up front until you step on the gas.”

Holden Torana LX SS hatch engine bay

The Magnuson 2.3L Heartbeat 2300 supercharger can safely run up to 17psi. Add E85 to the mix and making power has never been easier

It’s a more familiar recipe out back, where Muss opted for a nine-inch and adjustable four-link combo. With 35-spline Mark Williams axles and a Truetrac centre, it’s more than capable of withstanding the punishment Muss likes to dish out when he’s with his mates. And despite the rather tall 3.2:1 gearing, Muss reckons the blown L98 will still make a mess of the 275-wide ET Streets without breaking a sweat. “Just put it in top gear and stand on it,” he says. “But I love the fact that you can still drive the car like normal if you want to.”

Holden Torana LX SS hatch interior

Muss was chuffed with the job that Dr Stitch did in the cabin of the Torana, performing a restomod-style retrim that included a pair of Recaro buckets in the front, as well as covering the dash, centre console and door trims

You’ll find more of that restomod theme inside the car. While the fabrics and colours all look beautifully familiar, they’re wrapped around more modern fare, like the grippy Recaro buckets and well-executed speaker pods in the front and rear. The factory-style gauges have copped the techy treatment too, with Classic Gauge Restoration rebuilding the insides to talk to the L98, while the speedo talks to the satellites via GPS.

Holden Torana LX SS dash

The original horn button was recreated and covered too, with a healthy audio set-up finding its way into the mix courtesy of Pat at Ausrod

All in all, Muss says it took a mere four months to rebuild the car – a timeframe that is apparently pretty normal for him. “For me, it’s the thrill of the build. I already have another four-door LX in the build,” he says. “This one is tubbed and ’caged with a half-chassis that will run a twin-turbo set-up. The engine is over at Russo’s now. It should be finished in about six months.

Holden Torana LX SS hatch door trim

“I could have done a lot more with this car,” he continues. “I didn’t use anything from the original car. It’s all new – every nut and bolt. But I just wanted it to be clean and tidy. Being an SS, I didn’t want to go too far and wreck it. They’re too hard to come across these days. If you do find one of these it’ll cost you $100K, stock.”

Holden Torana LX SS hatch rear seats

When we ask if he has plans to build anything other than Toranas in the foreseeable future, Muss pauses before answering: “Yeah, I want to build an EH to honour my dad. He had a light blue 1964 Special with triple SUs, widened and chromed steelies and caps – that kind of thing. He loved the EH and bought one new when he first came to Australia, but mine won’t be an homage. It’ll be built how I think it should be done.”

We can’t wait to see that!

Holden Torana LX SS hatch console

MUSS AYRI
1977 HOLDEN LX SS

Paint: PPG A9X White

ENGINE
Brand: GM L98 6.0L
Induction: Magnuson Heartbeat 2300 supercharger, GM fly-by-wire throttle
ECU: GM
Heads: L98, Manley pushrods, Russo lifters, billet rocker covers, ARP studs
Camshaft: Russo Performance
Conrods: L98
Pistons: L98
Crank: L98, ARP studs
Oil pump: High-volume, Aeroflow sump
Fuel system: Bosch fuel pump (PULP), Turbosmart regulator, Bosch injectors, braided lines (E85 ready)
Cooling: PWR alloy radiator, twin thermo fans
Ignition: GM
Exhaust: Custom ceramic-coated headers (17/8in primaries) and twin 3in ceramic-coated system (part stainless, part mild), twin Turbo Exhaust Centre mufflers

TRANSMISSION
Gearbox: TH400, reverse pattern, transbrake, B&M Stealth Pro Ratchet shifter
Converter: 3200rpm Dominator
Diff: Ford 9in, 3.2:1 final drive, 35-spline Mark Williams axles, Truetrac centre

SUSPENSION & BRAKES
Front: Southern Chassis Works (Curley’s) tubular IFS and steering, Viking coil-overs
Rear: Bilstein shocks, adjustable four-link, chrome-moly single-piece tailshaft
Brakes: UPC twin-piston discs (f) drums (r); custom hard-lines and braided flex-lines; A9X master cylinder and booster

WHEELS & TYRES
Rims: Weld AlumaStar; 15x9 (f), 15x10 (r)
Rubber: Hankook Optimo 225/60R15 (f), Mickey Thompson ET Street S/S 275/50R15 (r)

THANKS
Russo Performance; Ante Rasso Fabrication; Ricky’s Drive Shafts; Kevin Gilbert at Grange Smash Repairs; Dr Stitch; Pat at Ausrod; Smithfield Diff & Gear; Ernicks Fibreglass; Classic Gauge Restoration

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