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Harrop-blown LS3-powered 1953 FJ Holden sedan

By Simon Telford, 06 Dec 2020 Features

Harrop-blown LS3-powered 1953 FJ Holden sedan

Grey motors are great and all, but how about this supercharged LS3-powered FJ!

TALKING to Peter Hampton and his dad Geoff, I instantly recognise childhoods spent around FX-FJ Holdens. Peter debuted his blown LS3-powered FJ at the FX-FJ Holden Nationals at Murray Bridge late in 2018, and while it is a high-tech car, it’s the culmination of three decades of tradition.

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

Geoff recalls how it all started: “My father bought an FJ new in 1956. He gave it to me when I was 16 to get my licence. The condition was that I couldn’t modify it, so I built up a hottie later on.”

Holden FJ

An aluminium fuel tank replaces the stocker, but it was tucked up into the body to avoid the A9X drop tank look

Peter and his three siblings grew up around Southern Earlies FX-FJ Club activities, so it was almost inevitable that he would be drawn into the humpy orbit. “My first one was an FX with a full-house grey and a five-speed,” he says. He’s still got the ’48, but he wanted something more. “The idea was to build something with a lot more grunt and as low as it could be, practically and legally,” says Peter. “And it had to look as close to standard as possible.”

When his FJ build started almost 20 years ago, the plan was to go with a Holden V8, but as time went on, an LS swap looked more sensible. “We found a written-off VE Senator with low kilometres, which gave us the LS3 and six-speed auto,” Peter says.

Read next: Chopped 427-cube Holden FJ coupe

Holden FJ front

A good plan, but one that would require some serious engineering to be safe and pass rego.

“We love these old Holdens, but they are pretty flimsy in standard form,” says Peter. “We got Josh and Joel Smith from Autest involved to ensure we were on the right path from the outset.”

Read next: Twin-turbo LSX-powered 1954 Holden FJ ute - PRIMED

Holden FJ side

The solution included the usual boxed Y-frames and chassis reinforcing but added in a few twists, including the rear floorpan, diff and suspension from a VK Commodore.

Up front is a Rod-Tech independent set-up, complete with rear-mounted steering rack and VT Commodore discs.

Other mods needed to get the late-model driveline into the FJ included a large transmission tunnel and a recessed firewall. “The six-speed is a large gearbox,” says Peter. “We wanted to get the car low, so we needed to get the trans up into the body.”

Read next: Chopped LS1-powered Holden FJ coupe custom

Holden FJ boot

While Peter and Geoff are both pretty handy blokes, they are quick to acknowledge that they had a lot of help with the build over the years. “We work in the building industry,” says Geoff. “If we could make an FJ out of wood, we would! So we had a lot of help from mates and old-school tradesmen.”

A key figure in the build was the late Ashley Hobson from the Classic Performance Dyno Centre. “Ashley was a very clever guy,” says Geoff. “He had a very cool Mark II Zephyr with a blown Tickford motor in it. The FJ was fully assembled and running prior to paint. It was then painted and ready to go back together when Ashley passed away.”

Holden FJ battery

The neat door for the relocated battery was already done when Peter first bought the car. If you look in the corners of the boot, you can see the upper shock mounts for the VK Commodore rear end

FJ fans will spot many clever ideas in this build that are tributes to Ashley’s craftsmanship. “Ashley’s philosophy was to use as many factory parts as possible,” says Peter. “That way, the parts will always be accessible off the shelf or from the wreckers. That’s why the brake booster and master cylinder are VS Commodore; the radiator hoses are Commodore. ‘Keep it straightforward’ was the idea.”

Holden FJ suspension

Ashley was also responsible for the countless jobs needed to get the engine swap working sweetly and looking good, including the trick over-the-radiator air intake. “The radiator was custom-made by PWR to be as big as possible without having to cut the car up too much. We didn’t want to run a pod filter; we wanted a smooth, factory-style look,” says Peter. “That’s why we tracked down this specific Harrop supercharger kit with the straight-on throttlebody rather than angled.”

The paint and panel was handled by Matt Bailey from Adelaide Custom Paint & Body. “Matt is another amazing old-school tradesman,” says Peter. “He can do just about anything, and nothing was too much trouble for him. He went out of his way to help us. Since the car has been finished, other paint and panel guys have made a point of finding me to compliment his work.”

Holden FJ under

Body mods on the FJ were subtle and kept to a minimum. The rear guards were welded to the body for maximum smoothness and the centre pillar tucked in to match the profile of the doors. And because FJs only came with headlights and a single tail-light from the factory, circular indicators and extra brake lights were frenched into the body.

Holden FJ wheel

The only other exterior body mod of note was a slight pump to the front guards to accommodate the VS Senator rims. “Originally, I wanted wide steelies and hubcaps, but I couldn’t do it without sacrificing dish,” Peter says. “Then I thought that the Senator rims had a bit of a Superlite style to them, so I’ve gone with that for now.” FJ freaks, however, will notice many body areas that have been smoothed over, including the notoriously difficult spot where the A-pillar, bonnet and firewall meet.

Holden FJ engine bay

The Harrop-blown LS3 was nestled in the FJ’s engine bay without having to cut the inner guards, but the firewall has been recessed, drawing the show-goer’s eye to the blower drive pulleys

Danny Anderson from Trim-Tech Motor Trimming & Upholstery in Kadina, SA stuck his hand up to do the trim job right at the start of the build, and years later came good with a masterpiece in Dove Grey leather. The front seats are cut-down Subaru Outback buckets, while the steering column is VL Commodore, topped by a SAAS tiller that is adorned with an original FJ horn button. There is a custom console to house the VE shifter, and the factory gauge set was replaced with a comprehensive set of VDOs, including a GPS speedo.

Holden FJ engine bay

The slick OTR intake sucks through the factory radiator support and iconic FJ grille like it was meant to be there

Ashley’s passing meant the team was up against it to make it to the car’s planned debut at the 24th AEHF FX-FJ Nationals at Murray Bridge at the end of 2018. “The car wasn’t quite finished, but we took it anyway and won Top Mechanical,” says Peter. “Nick and Anthony from THR Developments really helped us out at the pointy end. They tuned the car for us, sorted out some electrical gremlins, helped set the ride height and road-tested it before it went to Regency.”

Holden FJ interior

Seats are cut-down Subaru Outback items, while the tiller is a SAAS Classic with an FJ horn button. Gauges are from VDO

The hard work and dedication that went into the project was fully justified the next year at the Extreme Auto Expo, where the FJ took out Top Innovation & Engineering and Top Undercarriage & Driveline in the Street Elite class.

“I’m so happy with it,” says Peter. “It makes around 550hp, but it is still a fairly light car, so it goes hard. I wanted to put a six-speed manual in it at one stage, but I’m glad we went auto – it would have been a handful with a manual! It’s fast, but it’s also enjoyable to drive. We went to a lot of trouble to keep excess heat and noise out of the interior, so the whole family can enjoy the car. It’s great!”

Holden FJ gauges

ONE HUMP OR TWO?

WHEN Peter’s FJ won Top Innovation & Engineering at the 2019 Adelaide Auto Expo, it completed a circle that goes back to 1984 when his dad Geoff’s turbo six-powered FJ won the equivalent award at that year’s Street Machine Association of South Australia Show ’n’ Shine.

Holden FJs

V8 conversions were all but forbidden in South Australia at the time, making the water-injected turbo deal a good option. Behind the force-fed red motor was an Aussie four-speed, with a complete SL/R 5000 rear suspension and diff out back. The FJ has a fat stance over a set of 15in Superlites.

SMOTY winner Colin Townsend helped Geoff get the mechanicals set up, and it was by all accounts a swift ride for the day. “It got along pretty well,” says Geoff.

Holden FJ engine bay

And yes, Geoff still has the FJ his dad bought in 1956, and he is also the custodian of one of Australia’s most famous wild customs, Bob Moule’s Bobcat.

PETER HAMPTON
1953 FJ HOLDEN SEDAN

Paint: Glasurit Skipper Blue

ENGINE
Brand: GM 6.2L LS3
Induction: Harrop 1900 blower, custom OTR, GM fly-by-wire throttlebody
ECU: Factory
Sump: Custom
Fuel system: In-tank pump
Cooling: Custom PWR radiator
Exhaust: Custom extractors, 2.5in twin system, 3in dump
Ignition: LS3 coils and leads

TRANSMISSION
Gearbox: 6L80E
Converter: Custom
Diff: Shortened VK Salisbury

SUSPENSION & BRAKES
Front: Rod-Tech front end, coil-over suspension
Rear: VK coil suspension, Pedders springs and Panhard bar, Koni shocks
Brakes: VT Commodore discs and calipers (f & r)
Master cylinder: VS Commodore

WHEELS & TYRES
Rims: HSV VS Senator 17x8 (f & r)
Rubber: Kumho; 215/45/17 (f), 245/45/17 (r)

THANKS
My wife Amanda, who is very supportive – her understanding of cars meant I could not build the FJ without full disclosure
throughout; Max Bowman; Nick and Anthony at THR Developments; Danny Anderson at Trim-Tech Motor Trimming & Upholstery; Josh and Joel Smith at Autest; Kahn at Rare Spares Adelaide; Karl at Delway Australia; Matt Bailey at Adelaide Custom Paint & Body; the late Ashley Hobson of Classic Performance Dyno Centre