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Turbo LQ9-powered 1974 Holden LH Torana

By Kian Heagney | Photos: Chris Thorogood, 16 Aug 2020 Features

Turbo LQ9-powered 1974 Holden LH Torana

Under the rather unassuming white body of Mick Jahnecke's Torana lies a thunderstorm of turbo LS fury

IT’S a quandary for anyone considering pulling apart a pristine and original LH Torana in the 21st century: do you leave it as-is in tribute to Australia’s golden era of chrome-bumper motoring, or build it into something mental to blow your socks off? The choice Mick Jahnecke ended up making with his LH is something he contemplates to this day. “It was a two-owner car when I got it, and I probably shouldn’t have pulled it apart,” he laughs.

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

Holden LH Torana rear

While some may be upset that the LH is no longer sporting its original driveline, we think that 680rwhp of turbo LS sounds much nicer than an asthmatic 202 and Trimatic slushbox!

Read next: 1000hp twin-turbo LH Torana streeter

Mick got the car roughly 10 years ago as a replacement for his previous wheelstanding ‘PRO400’ LH Torry. “I was a bit over it, so I sold PRO400 and thought I’d take a break,” he says. The break didn’t last long though; just over 12 months later Mick got his hands on his new white LH.

Holden LH Torana front

PRO400 had a hot all-motor SBC, and Mick originally planned to follow the same path with his new steed. “I already had a small-block ready to go for it, but then I saw a mate’s blown SS at Winton one day and thought that was a much better way to make power,” he says.

After some research, Mick picked up a fresh cast-iron LQ9 LS mill from Eagle Auto Parts, and went from there. “I used advice from my machinist, Eugene from Flowcraft, for what we needed, and I was chasing around the 500rwkW [680rwhp] mark.” The mill was given a thorough makeover, consisting of Callies crank and rods, Diamond pistons and upgraded head gaskets and head studs with a custom-grind camshaft. The bottom end is sealed with a Holley sump, while the top end consists of Flowcraft CNC-ported cathedral-port heads and a Proflow sheet-metal intake manifold. Strapped to the side of the 408-cuber is a standard pair of intake manifolds, feeding a custom-made JPC 80/88mm hairdryer neatly hidden inside the engine bay. On pump 98 and using a standard VY Commodore SS ECU, the package pushes out 687rwhp on 15psi.

Holden LH Torana side

Mick agonised over the colour, and still wrestles with his choice to this day. He opted for white instead of silver, keeping true to the car’s original hue. However, he is considering adding SL/R striping to break up the white exterior

The rest of the driveline has been beefed up to suit. A Reid-case Powerglide plays host to a 3800rpm Dominator converter and transbrake from DTM Transmissions, while the rear end is a sheet-metal nine-inch from Geelong Diffs, sporting 35-spline axles and 3.7:1 gears.

Read next: Quentin Feast's twin-turbo LS-powered 1974 LH Torana - GMPWR

“It’s a pretty good thing to drive,” says Mick. “You’ve obviously gotta be a little bit careful where you light it up, but the response from the JPC turbo is awesome, with very little lag.”

Holden LH Torana underside

Mick has kept all the piping snug and hidden away under the 408ci LS, including the 60mm Turbosmart gate. You’ll only find out about the beastly turbo system when it’s too late!

Mick has put some decent hours of his own into the project, piecing it all together in his garage before getting the pros to handle the specialist jobs.

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

“I tacked together all the piping before getting it professionally TIG-welded, put the new interior in, made the engine mounts – a lot of those jobs that are needed in a build like this,” he says.

Holden LH Torana engine bay

The engine bay has been cleared of any unwanted clutter, including the brake ancillaries, which Mick has removed and replaced with Wilwood under-dash hardware 

The major fabrication was taken care of by Mick’s friend Paul, who hid the turbo snugly in the engine bay to keep it away from prying eyes. “I wanted to keep it looking simple and fresh in the engine bay; that’s why we shaved everything out and did the Wilwood under-dash brake set-up and things like that,” Mick says.

Inside, the Torry copped a decent makeover, but Mick decided he wanted to keep things looking as factory as possible. The interior trim colour shifted from brown to black with a sprinkle of GTS and SL/R parts, the only modern touch being the B&M Pro Stick shifter. Mick also added a complete bolt-in chrome-moly rollcage from Marshall Speed Shop to keep things safe at the track.

Holden LH Torana engine bay

The exterior got a nice new lick of white paint from Autoshape Restorations, and while Mick wasn’t sold on bolting fancy SL/R kit to the LH, picking the colour was a real teeth-grinding choice for him. “I was torn between white and silver, and if I was to do it all again I’m still not sure what colour I’d choose,” he says. “But the car was originally white, so white made sense.”

Holden LH Torana interior

The chrome-moly rollcage from Marshall Speed Shop is a removable bolt-in affair, meaning Mick can revert back to full street mode and take the family for a spin in the beast without any taxi bars getting in the way

Mick finished up the project around 18 months ago, and since then he hasn’t had much of a chance to really stretch the car’s legs. “I’ve taken it out a few times and it’s been great so far,” he says. “I took my seven-month-old daughter out for a cruise on Australia Day.” He does have plans to take it to the track, and if things go well it should push out some solid numbers. “I’ll change the rear springs and shocks, and it should run high eights pretty easily,” he says.

Holden LH Torana dash

Mick used special Speedhut gauges with the new LS gear, meaning he retained the factory look and feel he was after for the interior without having to rely on 46-year-old dials

As well as taking the LH to the strip, Mick will probably smoke up a storm at Powercruise as well, once we all have a little bit more freedom of movement. But for now, he’s planning on just enjoying the fruits of his labour after a long build.

Holden LH Torana centre console

MICK JAHNECKE
1974 HOLDEN TORANA

Paint: White Tinter

ENGINE
Brand: 408ci LQ9
Intake manifold: Proflow
ECU: VY SS
Turbo: JPC 80/88mm
Heads: Flowcraft CNC
Camshaft: Custom grind
Conrods: Callies
Pistons: Diamond
Crank: Callies
Fuel system: Aeromotive Phantom dual pumps
Cooling: PWR radiator
Exhaust: Standard manifolds, 4in turbo-back system

TRANSMISSION
Gearbox: Powerglide
Converter: Dominator 3800rpm
Diff: 9in, 3.7:1 gears, 35-spline axles

SUSPENSION & BRAKES
Front: Viking coil-overs
Rear: Lowered springs
Brakes: Wilwood 290mm discs and four-piston calipers (f & r)
Master cylinder: Wilwood under-dash

WHEELS & TYRES
Rims: Weld RTS 15x4 (f), Weld AlumaStar 15x8 (r)
Rubber: M/T 26x6 (f), M/T 255/60 (r)

THANKS
Flowcraft; Tony from TDR; the boys from DTM Transmissions; Paul from Autoshape Restorations for the paint; Matt from Geelong Diffs; Shane from Marshall Speed Shop; JEM for the wiring; Moolap Mufflers; my friend Paul for taking care of the fab work; all the boys for their help along the way; my wife Clare for the support and putting up with the long build

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