Peter Sauer’s monster 1970 HG Brougham

In 1970, Holden's HG Brougham was the absolute height of luxury. All that was missing was a 2500hp twin-turbo fatty

Photographers: Chris Thorogood

Queensland fella Peter Sauer has an enviable array of toys. Among them is a wild, blown and injected, Warwick Yellow HK Monaro famed for smoking out Powercruise events, along with a nitrous-huffing Mercury Comet that’s a crowd favourite at Kenda meets on account of its sky-high wheelies and five-second eighth-mile ETs.

First published in the October 2022 issue of Street Machine

However, if you can believe it, Peter’s latest build is cooler again: this here HG Brougham, which hides a mental, 565ci Dart-blocked rat motor beneath its factory bonnet, force-fed by a matching pair of 88mm Garrett snails. It’s yet to see a dyno, but Pete is quietly confident that the HG will deal out 2500hp at the hubs, and trundle down the quarter in seven-odd seconds.

If that’s not impressive enough, take the time to study just how well-packaged and beautifully detailed it is. Concealing a 2500hp fatty beneath the bonnet is a job in and of itself, but to do it in such a practical, aesthetically pleasing way is a credit to Justin Simpson from Horsepower Solutions, who was the driving force behind the project.

What has us particularly excited, though, is that despite the car’s show-quality finish that wowed crowds at Meguiar’s MotorEx earlier this year, it was built first and foremost for Street Machine Drag Challenge.

“Yep, that’s what we built it for,” Peter confirms. “I’ve done Drag Challenge Weekend in my blown HT Monaro and my VK. That was pretty cool, but I want to be competitive in this car and take it down to Melbourne for the five-day event. Driving it as far as I plan on driving it, it had to be pretty subtle, and that’s why it looks the way it does.”

Peter has long been a fan of Broughams and owns two HKs – a stocker and a 500hp streeter – but he longed to build a proper toughie. This HG popped up for sale as a primered roller, so he jumped on it and hooked in.

A 502ci big-block with smaller turbos was first fitted, with Peter getting as far as having all the piping, intercooler, manifolds, transmission, diff and wheels sorted. But it soon became apparent that he needed to step things up somewhat.

“Street cars just kept getting quicker and quicker, so I knew that we needed to go bigger in order to remain competitive,” he says. “So we made the call to remove that stuff and go to the 565ci engine and bigger 88mm turbos.”

Justin at Horsepower Solutions screwed the motor together, starting with a Dart block, to which he added a Callies Magnum crank, Oliver rods and custom JE slugs. The heads are Brodix BB3 items, and the super-trick, low-profile inlet manifold and throttlebody were machined up locally by Billet Inc.

The turbos are Garrett 88s, and the turbo system and custom water-to-air heat exchanger were fashioned by Dan Swanney at Promodz Fabrication, who also took care of the tubs, transmission mount and rollcage.

Justin emptied the Haltech catalogue into the car, including an Elite 2500T ECU, iC-7 dash, a multitude of sensors and Haltech coils for spark. Twin Aeromotive external pumps fetch fuel from the factory tank and deliver it to the engine; it is set up to run on pump fuel or just about any kind of race gas depending on the application, which is a handy thing for Drag Challenge.

Al’s Race Glides built the two-speed Turbo 400 trans, which is equipped with a Hughes bolt-together converter with a two-stage dump system. The rear end is suitably heavy-duty – a Race Products floater with 40-spline, gun-drilled axles.

Chassis-wise, there are no major departures from stock. The standard front end has been retained but now benefits from a rack-and-pinion conversion, tubular arms and custom-valved Menscer shocks. A set of chassis connectors stiffen things up, while at the rear the stock suspension has been replaced by a Motor Fab leaf and slider set-up, moved inboard for tyre clearance and paired with another set of Menscer dampers.

Mini-tubs were installed out back to accommodate 15×10 double-beadlocked Weld AlumaStars wearing 275/60R15 Mickey Thompson ET Street drag radials, and will land the car in the Haltech Radial Blown class for Drag Challenge.

Aesthetically, the thing is an absolute peach. Wheels and tyres aside, it could almost pass for a stocker, with the factory vinyl roof recreated by trimmer Dean McHugh, and all the original Brougham trimmings remaining in place. Even the paint is inspired by factory colour Tennyson Turquoise, tweaked for added pop and expertly applied by Corey Phie at Street Elite.

The chrome-moly ’cage is of course required for trips down the strip, and Peter has a set of aluminium race seats that will be trimmed in factory material and fitted up before the car ventures down the quarter. The Haltech iC-7 dash has been fitted just north of the air-operated shifter, providing a bunch of handy information without the need to do away with the stock Brougham instrument cluster.

BEWARND has been complete for a couple of years now, but with MotorEx delayed multiple times due to COVID, it has spent that time in hiding awaiting its unveiling. “All I wanted to do was race it, so it was hard to keep it under wraps, but fortunately I had the other cars to distract me!” Peter laughs.

“I can’t wait for Drag Challenge, and the first time I had the chance to drive it on the street was for this photoshoot, which felt unreal! I’ve been getting into the no-prep stuff with the Comet and doing pretty well, so I’ll probably move in that direction with that car and get the Brougham out for some Kenda radial stuff in the OG275 class.”

It really is a swiss army knife of a car – equally at home stunning crowds at fancy indoor car shows, making monumental numbers on the dyno, hurtling down the quarter, or cruising to the pub for a countery. And we sure as hell can’t wait to see Peter stick it in the beams at Street Machine Drag Challenge.


Paint: Custom Glasurit Tennyson Turquoise 
Brand: 565ci big-block Chev
Induction: Custom Billet Inc intake manifold, custom water-to-air intercooler
ECU: Haltech Elite 2500T
Turbos: Twin Garrett 88mm
Heads: Brodix BB3
Camshaft: Comp Cams custom HPS grind
Conrods: Oliver
Pistons: Custom JE
Crank: Callies Magnum
Fuel system: Twin Aeromotive
Cooling: Custom radiator with PWR core, SPAL fans
Exhaust: Custom twin 4in system
Gearbox: Al’s Race Glides two-speed Turbo 400
Converter: Hughes bolt-together, two-stage dump system
Diff: Race Products 40-spline floater, gun-drilled axles
Front: Rack-and-pinion steering, tubular arms, Menscer shocks, heavy-duty
Rear: Motor Fab leaf spring and slider kit, Menscer shocks
Brakes: Wilwood (f & r)
Master cylinder: Wilwood
Rims: Weld AlumaStar; 17×4 (f), double-beadlock 15×10 (r)
Rubber: Mickey Thompson ET Front (f), Mickey Thompson ET Street 275/60R15 ®

Justin Simpson at Horsepower Solutions; Dan Swanney at Promodz Fabrication; Dean McHugh; Nick Able; Mark Sauer; Ash Mason at WTS; Macca at Suspension Dynamics; Corey Phie at Street Elite; Kevin Harnell; Graeme Mackinnon; Justin Cook.