Twin-turbo 440-cube 1986 HDT VL LE Calais

Street car, show car, or drag car? Nathan Borg's genuine HDT LE is all three, with a 1250rwhp 440ci LS, elite detailing and PB of 8.1@171mph first time out!

Photographers: Nathan Jacobs

BUILDING cars always involves compromises; whether it be sacrificing outright horsepower for driveability, or not going to the trouble of Elite-level detailing on a street car, or not putting a million killer wasps under the bonnet of a show car or weekend cruiser. But what if you wanted it all wrapped up in one package, like former Summernats Grand Champion Nathan Borg did?

This article on Nathan’s VL Calais first appeared in Street Machine’s LSX Tuner #8 magazine, 2018

“Most of the early Commodores we do run manual steering, and Nathan’s VL is the same,” says Adam. “The front end is an off-the-shelf MacDonald Brothers Racing tube front end with double-adjustable Viking coil-over struts. Down the back, the VL uses adjustable coil-over struts by Strange Engineering”

In this instance, the Sydneysider gave Adam Rogash from MPW Performance in Melbourne a buzz and asked him to build a twin-turbo LS-powered first-generation Commodore that would run single-digit times, be good to take the kids for a cruise around the streets, and not look out of place on a stand at Motorex. That recipe and the MPW name may sound familiar together because Adam and the MPW crew built a 440ci LS-powered VK Commodore called ALLSHOW last year, and the Blue Meanie tribute has gone 7.75@180mph.

With prices for mint-condition original HDT cars exploding through the $100,000 and, in some cases, $300,000 bracket, it takes a brave soul to chop one up, as Nathan has done. The VL LE was the first HDT to offer a turbo six-cylinder option with a 150kW RB30ET available before the carb-fed 304ci Holden V8 was added later on

“We were building ALLSHOW when Nathan came to us and asked us to build a car with a similar concept,” explains MPW co-owner Adam. “He said we do some cool stuff and he’d talked to a heap of other shops who said it couldn’t be done.”

Never one to shy away from a challenge, Adam and Luke Foley took on the build, and it is at this point that Holden purists might want to stop reading.

“So Nathan’s car is a genuine turbo six HDT LE,” says Adam. While most people would start with roughie full of dents and rust, then spend months getting everything straight for a good paint job, Nathan started with a rare, mint-condition genuine HDT VL.

“It was disgusting how clean this car was,” laughs Adam. “I was about to start work on it but I had to ring Nathan and double-check he wanted to cut up a pristine, original LE!”

The four-piston Wilwood brakes are set up to run without a booster, utilising a Wilwood manual master cylinder. The VL is cooled with a PWR radiator, while Plazmaman supplied some of their trick billet rocker covers to match the intercooler and intake manifold

Powerhouse Engines built up an LS to the same specs as the engine in ALLSHOW, the latter having so far made a fairly lazy 1400rwhp on 24psi but could theoretically run up to 36psi if Adam chooses to push it. Starting with a Dart LS Next block and crank, Nathan’s motor uses Wiseco BoostLine rods and custom JE slugs to set the compression ratio exactly where Adam wants it.

“It’s around 9.5:1 compression so I wouldn’t say it is high-compression, but it works with the boost we want to run,” says Adam. “The tricky thing is, if you have too much compression you can’t run the boost we’d like to, but not enough compression means the engine becomes lazy.”

After putting bucketloads of research and development into finding a cam grind that works with this combo, Adam is keeping the exact cam specs quiet. The six-bolt heads have also been built by Powerhouse to their own recipe from blank castings, but you know they flow like crazy given the twin Turbonetics 75/75 turbos low-mounted in the inner guards under the headlights.

The snails push plenty of compressed air into a twin-entry, single outlet Plazmaman intercooler, which feeds one of Plazmaman’s awesome billet dual-injector intake manifolds. Fuel is squirted by 16 2200cc Bosch Motorsport injectors, drawing pump E85 from the custom fuel cell mounted in the boot that houses four Walbro 460L/hr pumps.

The pumps are staged in pairs so two pumps run all the time, while the final two kick in once the ECU reads over 10psi of boost pressure in the engine. Boost control management comes courtesy of Turbosmart wastegates and blow-off-valves, along with the Haltech Elite 2500-T ECU.

Behind the 440ci LS, a manualised, transbrake-equipped two-speed Powerglide transmission wears a Reid case and Dedenbear bellhousing, and has been stuffed with everything required to not only run sevens on the strip but stay alive on the road.

“We used a custom TCE 10.5-inch torque convertor,” says Adam. “The 10.5-inch convertor is needed to hold the power the VL will be making in the top-end of the track.”

The engine bay is functional, but also beautiful thanks to the MPW boys hiding the wiring and the plumbing, but also because they spent hours on the panelwork first. “It came to us with a ’cage and rear end in it, but we built pretty much everything else,” says Adam. “In the engine bay we welded up holes and shaved and remoulded everything, plus we wired, plumbed and fitted out all the mechanicals and electronics in the car”

On 22psi Nathan’s VL made 1250rwhp before it went back to Sydney to be fitted out with custom trim by Blackneedle Trimming in Penrith, who have done an absolutely killer job.

While many street/strip cars are fairly rough and ready inside, Nathan’s VL is an exercise in style. The Kirkey drag seats have been trimmed in a style sympathetic to the original HDT trim, while the rollcage hides behind the suede roof lining and the wheel tubs concealed behind the rear seat.

The cleanliness of the trim matches the smoothed, stark white engine bay perfectly, as every facet of the VL balances out the other. And this is because the MPW boys wanted the car to have a high-quality, balanced finish from the outset.

Based on the up-spec VL Calais, the HDT LE filled a gap in the market between the Holden Calais and the top-of-the-tree HDT Director. Nathan’s new interior is safe for speed but still has that original HDT feel, which Adam is a fan of: “The car was trimmed in Sydney by Blackneedle Trimming in Penrith; he is next level!”

“We wanted to keep the whole car as neat as possible, but also reliable,” says Adam. “We were working 18-hour days to get it done and we estimated we put 100 hours per week into it, totalling probably 2000 hours. Everything is custom on that car, even the turnbuckle and alternator mount are custom – that’s how tight that engine bay is!”

After wowing the crowds at Motorex Melbourne in 2018, XHDTX had a shakedown at Sydney Dragway in August where it ran 8.76@165mph straight off the trailer. After pushing a bit more boost into the big-inch LS, Nathan then ran an 8.1@171mph with plenty of pedal work in the top-end.

The Haltech IQ3 dash displays all the warning signals and engine vitals Nathan will ever need to know about thanks to the huge amount of data-acquisition the Haltech Elite 2500-T ECU provides. The VL has sensors to read exhaust gas temp, boost pressure, traction control, ethanol content in flex-fuel, plus dual widebands live reading air/fuel ratio and more. Adam can even log-in to the ECU from Melbourne and check the tunes when the car is in Sydney!

“I wanted something I could drive the kids around in,” says Nathan. With the potential to run deep into the sevens, the kids will get to the playground extra-fast and in style!

1986 HDT LE VL Calais

Paint: White

Brand: Dart LS Next
Capacity: 440ci
Inlet: Plazmaman billet
Crank: Dart forged
Rods: Wiseco BoostLine
Pistons: Custom JE
Heads: Powerhouse 6-bolt
Turbo: 2 x Turbonetics 75/75
ECU: Haltech Elite 2500-T
Fuel system: 16 x Bosch Motorsport 2200cc injectors, custom-made MPW fuel cell, 4 x Walbro 460 in-tank pumps
Cooling: PWR radiator, thermo fans
Exhaust: Custom twin 3-inch system

Gearbox: Powerglide, Reid case, Deadenbear bellhousing, transbraked
Converter: Custom TCE 10.5 convertor
Diff: Sheet-metal 9in, Mark Williams 35-spline axles, full floater

Front: Viking adjustable coil-over struts
Rear: Strange adjustable coil-over struts
Chassis: MacDonald Brothers Racing tube front-end, manual VL steering rack, mini-tubbed rear-end, custom 4-link
Brakes: Wilwood discs (f & r)

Rims: RC Comp Exile 17×4.5in (f), RC Comp double-beadlock 15x10in (r)
Rubber: Mickey Thompson Sportsman SR 27.5/4 (f), Mickey Thompson ET Street 295/55 (r)

Adam, Luke and the boys at MPW; Mark from Blackneedle Trimming; Chris from MacDonald Brothers; Pete Cleary for the ’cage and rear end; Ronnie Tarabay from Winner’s Circle for the paint; and the biggest thanks to my wife and family