WhichCar
Powered by
  • WheelsWheels
  • MOTORMOTOR
  • 4X4 Australia4X4 Australia
  • Street MachineStreet Machine
  • Trade Unique CarsTrade Unique Cars

Turbocharged EFI Holden 202-powered LC GTR Torana

By Boris Viskovic | Photos: Chris Thorogood, 03 May 2018 Features

Turbocharged EFI Holden 202-powered LC GTR Torana

Jeremy Cullen's GTR Torana has had a turboed 202 for over 20 years, but now it's been dragged into the 21st century

This article on Jeremy's GTR Torana was originally published in the April 2018 issue of Street Machine

YOU have to admire a bloke that has held on to his first car – a car he bought over 25 years ago and has been driven, raced, maintained and improved over those years. This isn’t a car that sat in the shed under a cover and recently got a bit of a birthday; it’s been on the road and sporting a hot Holden six with a turbo hanging off it for the past 20 years.

Holden Torana GTR rearIf Jeremy Cullen’s LC GTR Torana looks familiar, it’s probably because you saw our Grunt Hunt story on the car in SM, Oct ’17, where we mainly chatted about the motor and how Jeremy had dragged the venerable old Holden six into the 21st century with a new turbo, EFI and a whole heap of computer smarts.

Read more: Jeremy talks about the tweaks to his turbocharged black motor-powered LC GTR Torana

Holden Torana GTR frontWhile the old 202 made do with a draw-through carby set-up and a set of Starfire rods, it was still a pretty solid combination, punching out an 11.2@118mph. That same engine was upgraded with EFI and a bellyful of E85 and ended up running 10.7@128mph, but Jeremy figured he had a bit of a hand grenade just waiting to go off and decided against pushing the old combo much further.

It was at this point that Jeremy thought he’d treat the GTR to a bit of a freshen-up.

Feature: Nine-second supercharged LS3-powered Torana

Holden GTR Torana side“I started building a new engine and that was dragging on a bit, so halfway through I stripped the car back to nothing and started again with it,” he says. “I gave the car to a mate of mine, Paul at Autoshape Restoration, who did all the bodywork, stretched the guards, tubbed it and painted it back to the factory gold colour with the GTR scheme.”

Feature: Vortech blown Holden 304-powered LC GTR Torana

Holden Torana GTR wheelThe Torry rolls on 15x3.5 and 15x9 Weld Magnums, which wear 165/80 Hankook and 275/60 M/T ET Streets respectively

The entire car was dipped before receiving the full treatment top to bottom. The underside was cleaned up and given a coat of satin black. Tubs were added and the guards were stretched 85mm, which allows Jeremy to run a 275/60/15 drag radial on a nine-inch-wide rim. “Paul did an amazing job of putting in a piece and shaping it so it didn’t have a flat look along the top of the tyres,” Jeremy says. “It’s blended it in really well.” Pop the boot and there’s no carpet hiding all that gorgeous work, just more of the Platinum Gold paint offset by the gloss-black fuel tank.

Holden GTR bootThe show-quality paintjob extends into the boot area 

The inside of the car has been restored back to its factory black glory, with the only obvious diversions from stock being the TCI Outlaw shifter and the MicroTech display that has been mounted under the dash. While the GTRs came out with a pretty well-equipped dashboard, Jeremy figured a boost gauge was more important than an ammeter. Of course, there’s a whole bunch of info that can be displayed and logged by the MicroTech system, which means there won’t be any guesswork when it’s time to lean on the engine a bit and make some serious numbers.

Holden Torana GTR engine bayIndividual Bosch coil packs, EFI Hardware dizzy and crank trigger are controlled by a MicroTech LT-16c ECU, which gives Jeremy a lot more control over the motor compared to the old drawthrough carb set-up

Speaking of the engine, we better cover that off for those of you who didn’t see the Grunt Hunt story. It’s an entirely new combo, with the old one sold off and now living in Perth. As mentioned earlier, Jeremy was a bit worried about the old engine blowing up if he pushed it too far, so this one has been built with reliability in mind.

Holden Torana GTR turboThe block is a black motor from a VK Commodore, the last of the breed, and it’s been punched out 60thou to take the capacity out to 208ci. The stock crank has been nitrided and balanced, and Precision H-beam rods swing a set of SRP forged pistons. There’s a Yella Terra 12-port head that’s been CNC-ported, and Ivan Tighe has carved out a solid-roller cam with .582in lift. A set of 1140cc injectors make sure plenty of E85 finds its way into the cylinders, helped along by the GTX42 turbo and 90mm Proflow throttlebody that’s bolted to a custom-made intake plenum by Strop at Moolap Mufflers. It’s a very tidy installation, with a straightforward route from the turbo to the intake thanks to the lack of an intercooler – a benefit of running E85.

Holden Torana GTR interior frontThe interior has been restored to factory fresh, with the only changes being the TCI Outlaw shifter and MicroTech dash Dash display

While Jeremy hasn’t had a chance to get the car on a dyno or drag strip yet, he has clocked up a few kays ironing out the bugs: “I’ve probably done about 150km in it just to make sure everything is 100 per cent happy,” he says. “The motor feels a lot stronger down low – we’ve only run it on seven pounds of boost so far – but I’ll change the wastegate springs soon, which will bring it up to about 14. I was a little bit concerned about lag times with such a big turbo on it, but it actually comes on boost pretty quick.” With a bump in compression from 7.0 to 9.5:1, it’s no surprise the car feels a lot better off boost.

data loggerDon’t freak out about the ultra-lean AFR; the engine wasn’t running. Although all of the stock gauges still work, there’s a lot more info you can get from the MicroTech dash in regards to datalogging

Jeremy’s main focus after we last featured it was to get the car done for Summernats 31 and hopefully make it into the Top 60 tent. Well, he managed to do that and even go a couple better, making it to the Top 20 and also taking out the Top Tudor award. The next goal is to see if he can get that quarter-mile time down in the low 10s or maybe even a high nine-second pass. With the way Jeremy is setting goals – and kicking them – it’s a pretty sure bet he’ll get it done.

Holden GTR engine bayENGINE BAY

The engine bay is super-sano, with all unnecessary holes filled and the brake system moved under the dash. The pipework is nice and simple as there was no need for an intercooler with the E85 diet. Jeremy ran an XR6 turbocharger for a long time, but stepped up to a GTX42 that’ll probably handle around 1000hp. In reality, though, the engine is probably good for around 500hp, which is more than enough for low 10sec timeslips. A 90mm Proflow throttlebody feeds into a custom-made intake plenum that is similar in design but much larger than the unit fitted to the factory EFI 202 engines

Holden GTR Torana onroadJEREMY CULLEN
HOLDEN LC GTR TORANA

Paint: DeBeer Platinum Gold

ENGINE
Type: Holden 202
Inlet: Custom
Throttlebody: Proflow
Turbo: Garrett GTX42
Heads: Yella Terra alloy 12-port
Cam: Solid-roller
Crank: Black motor, nitrided and balanced
Pistons: SRP
Conrods: H-beam
Exhaust: 3.5in
Ignition: EFI Hardware crank and cam trigger, Bosch coils
ECU: Microtech LT-16c

SHIFT
’Box: Fully manualised Trimatic, transbrake,
Converter: 3500rpm Dominator
Diff: 9in, 3.5 gears, Truetrac, 31-spline axles

BENEATH
Front suspension: Pedders 90/10
Rear suspension: Viking double-adjustable coil-overs
Brakes: Wilwood (f & r)
Master cylinder: Wilwood

ROLLING STOCK
Rims: Weld Magnum; 15x3.5 (f), 15x9 (r)
Rubber: Hankook 165/80 (f), Mickey Thompson ET Street 275/60 (r)