Aussie Oddities: HDT Special Vehicles Magnum

Peter Brock needs no introduction. A maestro on Australia’s racetracks, the nine-time Bathurst winner parlayed his on-track success into a successful road car business – HDT Special Vehicles.

Starting with the VC Commodore in 1980, Brock sprinkled his magic onto and into almost every component of Holden’s family sedan, the result a sedan that looked tough and drove even tougher.

The high point came with the VK Commodore, the ‘Blue Meanie’ as it was dubbed, today a bona fide classic. The VH and VL followed but Brock’s star was about go supernova, his controversial energy ‘Polarizer’ sending Holden into damage control and Brock’s reputation and business empire into a black hole.

By the time the stardust had settled, Brock was out, Holden had taken control of its special vehicle division and the roll call of special Commodores that had been ‘touched by the hand of God’ had reached an end point.

Today, it’s the Commodores that are most revered and most remembered. Around 4000 Brock-fettled cars are believed to have rolled out of the company’s base in North Melbourne. Numbered amongst those is what is arguably the rarest HDT model of them all, the HDT Magnum.

No one is sure just how many of the WB Statesman-based Brock specials were produced but today’s wisdom suggests anywhere from ‘slightly less than 100 to around 120’. Whatever the final number, the HDT Magnum has been largely overlooked in the annals of Brock lore, overshadowed by the King of the Mountain’s street-tough Commodores.

Each of the around 100, give or take, Magnums started life as either a Statesman DeVille or Caprice. From here, Brock’s fairy dust worked over the 5.0-litre Holden V8 under the bonnet, with plenty of HDT go-fast bits – cylinder heads, inlet manifold, air cleaner, and the exhaust system all carried the Brock HDT imprimatur.

The result was a massive 50 per cent boost in power over the standard Holden V8, now rated at 188kW, significantly more than the regular Holden V8’s 126kW. And torque got a workout too, in Brock’s hands boosted to 428Nm against the donor engine’s 361Nm.

The chassis also underwent the knife, now with Bilstein gas shock absorbers all around while the front suspension geometry was revised, springs were uprated, while stabiliser bars also got the HDT treatment, now stiffer.

Inside, Statesman-like plushness greeted owners, the most obvious HDT treatment swapping out the incumbent’s luxo-barge steering wheel for the Brock signature Momo tiller.

The Magnum cut an imposing figure even standing still, sitting significantly lower on its standard-fit 15-inch Momo Polaris alloys while the Statesman’s existing chromework could be optioned in a combination of black and matching body colour while windows as well as the head- and tail-lights could be tinted. Suddenly, the Magnum looked less limo and more mean street machine.

Performance was commendable too, certainly for the time, the Brock-fettled Group 3 V8 mated to a beefed-up Trimatic three-speed automatic capable of hurtling the 1612kg limo from 0-100km/h in 9.43 seconds while the standing quarter mile was dispatched in 16.76 seconds.

Brock loved the HDT Magnum, labelling it “a weapon”. But then, he would say that about his hot-rodded limo which, in DeVille trim, asked for around $26,500 when new in 1984, around $5000 more than the Statesman DeVille donor car. A circa-$30k when new Caprice could easily blow out to over $35,000 with the Magnum upgrade and a few HDT options added.

Far from being a cosmetic kit, the WB Magnum was built to be a proper sports sedan. As Brock recalled: “It went hard. I remember going out to Calder (Park Raceway), and the best I could do with a stock Statesman was something like 61.5 seconds on a lap. And as soon as we whacked the Magnum out there – it had Pirelli P600s on that car – we were down in the 57 [seconds] dead. It was just like a weapon.”

The last HDT Magnum, a Cerulean Green DeVille, was sent to its new owner in 1985 with a single-gun salute, HDT’s Workshop Foreman Craig Fletcher posing beside the just-completed Magnum with an, appropriately enough, long-barrelled Magnum pistol. We assume it was a replica.

So what do you think of the HDT Magnum? Should the muscle limo be considered in the same regards as the armada of hot-rodded Commodores that came out of Brock's workshop? Let us know in the comments below.