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 LSX Tuner #8 magazine, 2018

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.

“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!”

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.”

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.

“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.

“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!

NATHAN BORG
1986 HDT LE VL Calais

THANKS
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.