Nitrous 622-cube 1974 Holden LH Torana

Looking back on Johnny Wilson's ET-smashing 7-second Holden LH Torana

Photographers: Tony Rabbitte

Looking back on Johnny Wilson’s ET-smashing 7-second Holden LH Torana

This article on Johnny’s Torana was originally published in the October 2009 issue of Street Machine

OVER the years hundreds of street machiners have set targets for themselves, on and off the track, only to fall short for one reason or another. Ask why and most will say it’s because they didn’t surround themselves with the best people. This is a mistake that Queensland racer, Johnny Wilson, has not made with his 622ci, nitrous-equipped LH Torana.

Each issue (in Urban Warfare) we highlight the merits of the racers in Street Machine’s ongoing Fastest Street Car Competition. The most exciting class for a long time has been Modified Street Blown, for the simple reason that the cars are real street cars and they must have over 1300hp to be anywhere near competitive.

Holden LH Torana“I’m ecstatic,” laughs John, who cut his teeth racing a genuine Bathurst HK GTS Monaro in Modified Street (SM, Jan 2006). “In the first three meetings with the car we have made all three finals, won two of them and reset the national record from 7.98 to 7.88.”

While Johnny has to be admired for the results, the car was screwed together by the best people in the country. The build was managed by Simon Kryger, the then record holder in MSB and a 10-year veteran of racing Toranas in this class.

“I’d been looking to buy a car for some time but didn’t really like anything I saw,” recalled Johnny. “I’ve only owned three cars in my life and I like to build every one of them to last me forever.

“At one meeting Simon gave me a hand to sort out a nitrous problem and we became mates. He offered to help me build the car using the same team of guys he used.”

A shell was sourced and stripped before being sent to Craig Burns at Streetcar Fabrications. Modified Street rules prohibit chassis work that goes beyond wheel tubs, cage and removable fibreglass bonnet and boot lid. With all that done, Craig fashioned a set of carbon-fibre bucket seats and door trims to keep down the weight, and saved some more kilos by fitting fibreglass bumpers and replacing the side window glass with polycarbonate.

To accommodate the 28 x 11.5 MT slicks, the rear wheel arches were stretched and the back doors modified for tyre clearance.

The 622ci Chevy was dummy fitted, and to avoid such an acute sump angle and to allow removal of the transmission with greater ease, the transmission tunnel was raised.

Other modifications include an under-dash Wilwood brake master cylinder, Wilwood front and rear four-spot brakes, fabricated nine-inch diff housing with full Mark Williams internals and coil-over shocks.

It took six months to knock the body into shape and a mate of mate, known as “Little Johnny”, finished the shell off with a coat of House of Kolor Wild Violet.

The engine is a work of art on all levels. Built by Norm at Northmead Auto Centre, in Sydney’s western suburbs, the 622ci big-block Chev makes over 1112hp in aspirated trim, 880ft/lbs and a staggering 1252hp at the tyres with a 500-shot of nitrous.

Torana LH rearFor Chevy lovers, this motor is a wet dream. The core is a Dart tall block with splayed steel caps, Lunati crank, Lunati billet rods and Ross Pro Mod pistons. The rotating assembly is good for about 2000hp, and with so many cubes, the engine needed a big set of heads. They plumped for Dart Big Chief 18 degrees units.

These have been fitted with titanium valves and on the flow bench they crank out an amazing 490cfm at 850thou of cam lift.

The rest of the engine is all top-shelf stuff, with Jessel rockers and cam drive, Moroso external oil pump, Steffs oil pan, front-mounted belt-drive dizzy, Eagle Race Engines sheet-metal intake manifold with twin 1150 Pro Systems carbs.

The twin-fours are fed by a Magna Fuel 5000 series pump that also feeds the Wilson nitrous system on the engine via a common fuel log and twin four-port regulators.

The engine is mounted front and rear with solid engine plates and the air/fuel mix in the 15:1 compression engine is fired by a massive 10amp ICE ignition system with a 24-volt ignition booster with programmable ignition curve.

The 23/8in pipes off the exhaust port are stepped to 2½in into four-into-one merge headers and a dual 4½in exhaust system.

A monster Powerglide by Northmead Auto, rated at 3000hp, backs up the powerhouse and is fitted with a custom 1.65:1 first gear, ringless input shaft and all the best components, including a TCE converter.

“I really built this car to run 7.50s with this combination,” states Johnny. “I’d like to run 7.50s and 185mph by the end of the year, although the car has been set up to run faster with a new twin-turbo combination that will come later.

“It’s really a case of common sense; big horsepower and a light car will always run fast … and this car drives easy. It feels like a granny’s car you can get groceries in.”

Torana interiorJohnny Wilson
1974 LH Torana

Colour: House of Kolor Wild Violet

Type: Chevrolet, 622ci
Block: Dart tall deck
Crank: Lunati
Rods: Lunati billet
Pistons: Ross Pro Mod
Heads: 18-degree Big Chief
Valves: Titanium
Rockers: Jessel
Intake: Eagle Motorsport sheet metal
Carbs: Twin 1150 Pro Systems
Nitrous: Wilson fogger
Dizzy: Belt drive
Ignition: 10 amp ICE, 24V ICE booster
Exhaust: 23/8in stepped to 2½in into 4½in merge collectors
Horsepower: 1112hp, 880ft/lbs, 1252rwhp with 500 nitrous shot

Gearbox: Powerglide, ringless input, straight cut planetary
Converter: TCE
Diff: Sheet-metal nine-inch, Mark Williams components: 3.5:1 Pro Gears, 40-spline gun drilled axles
Tailshaft: Chrome moly by Daniel’s Engineering with Mark Williams yolk

Springs: Pedders (f) lowered 45mm
Shocks: 90/10 (f), Strange double adjustable coil overs (r)
Sway bar: 32mm Pedders (r)
Brakes: Wilwood discs and four spot calipers
Master cylinder: Under-dash pedal assembly and remote reservoir

Mods: Mini-tubs, standard boxed trailing arms, Panhard bar, removable steering wheel, raised tunnel, sub-frame connectors, fibreglass bonnet, boot lid and bumper bars, polycarbonate windows, removable dash

Rubber: MT front runners, MT 28 x 11.5 rear slicks
Rims: Weld Magnums 15 x 4 (f), 15 x 10 (r)

Weight: 3100lbs
Best ET: 7.88
Best mph: 179mph
Power: 880ft/lbs, 1252rwhp with 500 nitrous shot

Photographers: Tony Rabbitte