HT Monaro GTS 350: Is This Holden’s Greatest Muscle Racer?
Holden’s enviable motor sport legacy is largely credited to the success of Toranas and Commodores. However there will always be a special place reserved for the unique achievements of the mighty HT Monaro GTS 350, which not only won the Bathurst 500 on debut but was also the first Holden and first Australian-made car to win the Australian Touring Car Championship.
Stormin’ Norm Beechey took his rightful place amongst the immortals of Australian motor sport when he won the 1970 ATCC. Up until then the nation’s premier touring car title had been dominated by imported makes since its inception in 1960; firstly Jaguar Mk I and Mark 2 before the mid-‘60s V8 onslaught of Ford Mustangs.
The challenge of building an Aussie car to the standards of the latest US Trans-Am factory racers, like Bob Jane’s ex-Shelby ’68 Mustang and Allan Moffat’s stunning ‘69 Boss 302 Mustang, was relished by arch rivals Ford Australia and General Motors-Holden. Both wanted to be the first to win the ATCC with an Aussie car.
Under the championship’s Improved Production rules, which were similar to the Trans-Am series, Ford’s approach was to hand-build a pair of XW Falcon GTs which became known as the ‘Super Falcons’.
They used top secret Trans-Am chassis blueprints from the US, paper-thin lightweight body shells and exotic fuel-injected V8 engines. However, the ambitious project was dogged by construction delays, massive cost blow-outs, poor handling and crippling reliability which ensured their much hyped 1970 ATCC attack never eventuated.
Beechey on the other hand, with the enthusiastic support of Holden, Shell and his small team of mechanics and engineers, designed and constructed a Monaro with pure Aussie know-how. It not only proved more than a match for the mega-dollar US imports but was built with a fraction of their development budgets.
In Series Production racing the year before, the HT Monaro GTS 350 also scored an against-the-odds victory in the 1969 Bathurst 500, after a disastrous debut at the Sandown Three Hour race only three weeks prior in which Ford’s new and demonstrably faster XW Falcon GT-HO raced to a debut win. Not only that, the new Falcons outnumbered the Monaros by more than two-to-one at Bathurst.
However, thanks largely to the vast experience and fox-like cunning of Harry Firth and his new Holden Dealer Team, The General shattered Ford’s pre-race favouritism with a convincing victory.
Beechey: How to build a ‘Trans-Aus’ Monaro
Despite Beechey’s gallant efforts to break the imported car strangle-hold on the ATCC in 1969 with an HK Monaro GTS 327, it was clear that the local cars would need a helping hand from the rule makers if they were to have a realistic shot at the title.
For 1970, governing body CAMS loosened up the technical regulations to allow a local car to be built along the same lines as the Trans-Am cars, with new freedoms in the key areas of suspension, brakes, weight distribution, body modifications, seating etc.
The new rules allowed Beechey to incorporate many innovations in an effort to improve the overall performance of the Monaro, but the concept of making a ‘Trans-Aus’ racer to match the latest Trans-Am cars was a formidable challenge.
For starters, the US builders were obsessed with saving weight, to the extent that acid-dipping of entire body shells and components had become so extreme that it posed a threat to durability and safety.
As a result, Beechey got very serious about weight reduction. All body sealing compounds were removed, many holes were drilled to remove excess metal, steel bolts were replaced with aluminium and every component came under scrutiny. For example, the Holden single-point distributor had a special alloy body that saved one kg. Aluminium battery cables saved three kg. Braided plastic fuel lines, another three kg. Lightweight fiberglass seats another 18 kg. And on it went.
Another Trans-Am specialty was moving the engine down and back to lower a car’s centre of gravity and reduce its polar moment of inertia (ie mounting heavy components as close as possible to the C of G can greatly improve agility and handling response).
As a result, the 350cid (5.7 litre) V8 was moved 100mm rearward and lowered 75mm to try and match the improved balance of the imports. Even so, the Monaro’s handling dynamics were still considered inferior to the US-built cars.
The Monaro also featured a clever fuel tank set-up that used weight distribution to improve traction. The fuel tank was divided into two chambers, so that one side or the other could be filled to transfer 56kg of fuel weight over the rear wheel that needed it the most.
Therefore, on circuits with a majority of right-hand corners, only the right tank (over the unweighted inside rear wheel) was filled. For tracks with a majority of left-hand handers only the left tank was used. In longer races, both were filled. The battery was moved to the boot and could also be mounted either left or right to enhance this wheel-weighting effect.
Serious thought was also given to the concept of being able to switch the car’s cabin configuration from right-hand drive to left-hand drive, so that Norm’s 90kg of physical ballast could also do its fair share!
Trans-Am cars also featured welded full-length roll cages that extended into the engine bay and boot area to provide substantial crash protection for drivers and create a stressed ‘space frame’ for big gains in chassis stiffness.
In response the Monaro was fitted with a cage of similar design. The front cross-member was also solidly mounted to the body’s frame rails and braced to the roll cage tubing and all internal front sheet metal was welded together to further increase chassis rigidity.
The front suspension’s upper and lower control arms were adjustable by way of alternative mounting points to reduce bump steer and adjust the front roll centre. Three positions for the top arms and two for the bottom arms were provided.
Front ride height was a full 100mm lower than stock to drop the centre of gravity further, with heavier coil springs and adjustable Koni shocks. To reduce unsprung weight the front wheels were feather-weight 15 x 8-inch magnesium Minilites from the UK. The live rear axle, fitted with the widest allowable 15 x 10-inch Minilites, was located by leaf springs as stipulated in the regulations. Beechey experimented with specially tapered single-leaf and multi-leaf units, with the chosen single leaf set-up saving another 20kg.
The axle housing was located by upper and lower trailing arms fitted with spherical rod ends and a superb Watts Linkage device for positive lateral location and rear roll centre adjustment. This required the anti-sway bar to be hinged from the roll cage, located about 300mm above the boot floor, with long drop links passing through it to the suspension pick-ups below.
Under the new 1970 rule freedoms, any type of brakes could be used provided they were of the same configuration as originally specified (disc or drum) and were produced by the same parent manufacturer.
The fact that Holden was a subsidiary of General Motors allowed Norm to use powerful Chev Corvette four-spot calipers and 260mm ventilated front discs, fed plenty of cooling air via neat aluminium ducting. The rear also benefitted from the GM parts bin, with Camaro rear drums fitted with GM sintered metallic brake shoes.
This set-up eliminated the need for a brake booster, so the extra room allowed the use of two EH Holden brake master cylinders - one for the front hydraulic circuit and one for the rear - providing a simple means of adjusting front-to-rear brake bias. This was done via a thread-adjustable bar on the brake pedal arm which controlled the amount of pedal pressure distributed to each master cylinder.
Under the bonnet, Beechey claimed the HT’s new hand-built wet-sumped 350cid V8 - which was bored out to 6.0 litres and loaded with the best internals - made more than 500bhp (372kW) at a spine-tingling 7700rpm, which were staggering figures at the time. The torque was equally shattering with 500ft/lbs (675Nm) at 5500-6000rpm. The induction system was a sight to behold, with four sand-cast 58mm DCOE side-draught Weber carburetors mounted on a magnesium Moon cross-over manifold.
Considerable effort went into fabrication of aluminium shields around the inlet trumpets on each side of the engine. These were designed to insulate the inlet charge from excessive under-bonnet heat and feed cooling air directly to the carbs from the bonnet scoops for maximum power.
Booming four-into-one exhaust headers dumped into long megaphones which exited just below the trailing edge of the front mudguards on each side. You can imagine the roar! And to stop the hot 350 from blowing its cool, there was a Corvette aluminium cross-flow radiator fitted with two Ford Galaxie header tanks welded together to maximise coolant capacity.
A Schiefer forged alloy flywheel and pressure plate assembly fed all that power to a choice of two gearboxes. One was a normal close-ratio Muncie M-22 ‘Rockcrusher’ based on that used in the Chevrolet Corvette. The other was a stock Holden Saginaw casing, with a beautifully machined straight-cut gear set made by transmission guru Peter Holinger. The Saginaw ‘box had a taller 3rd gear and was used to avoid extra shifts on some tracks.
A custom-made tailshaft transferred power to the hand-crafted live rear axle assembly, which (after the Warwick Farm round) used a full-floating design similar to the Trans-Am Mustangs that ensured an axle breakage would not result in the loss of a wheel.
Diff centre was a rugged 12-bolt GM Positraction unit with extra GM clutch plates and the factory’s heavy-duty spring pack, plus locally-machined 31-spline steel billet axles and hubs fitted with fat 1/2-inch wheel studs for maximum strength.
The driver’s compartment was another area that displayed some clever thinking gleaned from Norm’s many years of racing experience. Lightweight fiberglass bucket seats not only saved a lot of weight but got Norm sitting down nice and low in the car.
The gear stick was extended in height by some 300mm, so that in the heat of battle Norm only had to move his hand across to the left rather than left and down to change gears. This wheel-to-gear-stick relationship is now standard practice in the construction of many race and rally cars.
Mounted on top of the gear stick was a hand-throttle device that used a spring-loaded trigger and cable. This enabled Norm to more easily blip the throttle on down changes by simply pulling the trigger on the gear stick, rather than the traditional ‘heel and toe’ foot shuffling technique between brake and throttle pedals.
Another clever cockpit feature was the ‘fail-safe’ ignition system, which featured both a transistorised ignition and a conventional coil/condenser arrangement. The two systems were linked via two fuse holders mounted on the console. If one circuit failed, Norm simply had to move the fuse to the other holder to bring the back-up circuit into operation.
Beechey’s legendary HT Monaro GTS 350 is arguably the greatest Holden muscle racer ever built. Given that it toppled the best imports from the US (Mustangs/Camaros) and Europe (Porsche 911s) fair and square in 1970, it was indeed a world beater.
Bathurst 1969: Victory Against The Odds
The HT Monaro GTS 350 was not supposed to win the 1969 Hardie-Ferodo 500. Ford’s new XW Falcon GT-HO had more power and torque, bigger brakes, a much larger 36-gallon fuel tank and for the first time the works cars were fitted with the latest Goodyear Blue Streak racing tyres.
The Monaro’s unfair advantage, though, was Harry Firth. He had just taken the reins of the newly formed Holden Dealer Team after Ford had brought in American Al Turner to oversee its competition activities and advised Firth that his services were no longer required.
However, having won the Armstrong 500 four times as a car builder/driver/team manager/tactician, the wily veteran had developed an intimate knowledge of what was required to win a 500-mile (800km) race in showroom stock road cars and he applied that invaluable expertise to the HT Monaro GTS 350.
The HDT did not get off to a good start when its lone entry in the 1969 Sandown Three Hour race driven by Spencer Martin and Kevin Bartlett ran out of brakes due to severe overheating, crashed and burst into flames. This was only three weeks before Bathurst but Firth had long since mastered the art of using factory service bulletins and option codes to quickly get what he needed for Bathurst.
To cure the front brake overheating problem, factory-approved slots were cut into the sheet metal behind the front bumper on each side to improve cooling, along with deletion of the disc brake dust shields and new wheels with extra slots. He also fitted brake pads and linings made with a unique compound he’d devised that was well proven in previous 500s.
He also gained approval from GM-H for four large openings to be cut into the steel air filter canister to improve engine power. He also came up with fixes for the anti-tramp rods on the rear axle that didn’t allow enough tyre room and the rear gearbox mount that flexed at high speed and made the car jump out of gear.
His pit crew was thoroughly drilled in the art of changing front brake pads in record time, as each of his three HDT-entered cars would require two front pad changes to ensure they always had solid middle pedals in a race that was notoriously hard on brakes.
Firth also ran race simulations with the new Goodyear racing tyres the Ford team would be using and some Firestones, but decided that the speed advantage of the US rubber was not worth the risk as their wear rates were too high. He was also concerned that they did not have enough tread depth if it rained, so he stuck with his tried and tested Michelin XAS radials – a choice that proved decisive in the race.
His driver line-up included a young NSW rally star on the rise called Colin Bond, paired with fellow rally ace Tony Roberts; a black-eyed, goaty-bearded, 20-something year old sports sedan racer and Bathurst rookie from Victoria called Peter Brock teamed with Bathurst veteran Des West. And, in a third HDT Monaro, Firth took another different tack with open-wheeler drivers Peter Macrow and Henk Woelders.
Firth copped criticism by some for not selecting big name stars. However, he knew each of his drivers’ capabilities and, most importantly, he wanted a ‘champion team’ rather than a ‘team of champions’ who would do exactly what they were told to do. Bathurst experience had taught him that star drivers (with egos to match) could easily derail the best-laid plans.
Firth did not to show HDT’s hand in practice at Bathurst (qualifying seventh, eighth and 10th) even if that meant the new GT-HOs grabbed the Saturday headlines. However, come Sunday he would be in a position to push them hard from the start and see where everyone was placed come the first round of scheduled pit stops. And that was exactly the way the race played out, according to his personal memoirs immortalized by Chevron Publishing:
“Nearing the first round of scheduled stops, it all started to come apart for the Fords when their Goodyears started blowing out. We were now in front and going along very nicely at a pace that was not torturing the cars. Woelders, who clearly was not comfortable, pulled in early and swapped to Macrow (who drove it for the rest of the day), Roberts took over from Bond and Brock replaced West. Our very quick stops saw us hold the lead.
“The Fords would close up again only to blow more tyres, so the HDT ‘first timers’ were looking good. Comments by the TV and course commentators about our inexperience and what they thought was going to happen were so funny, because they completely forgot about how many Phillip Island and Bathurst 500s I’d already won - and that this one was no different!
“At half distance, we called in our lowest-placed car first (Macrow) for new front pads and fuel, as a practice run to make sure there were no mistakes made when we brought the other two higher-placed cars in for their pad changes. We changed pads on all three cars on their scheduled laps and all in the planned 2 min 45 secs. The Ford guys just couldn’t believe the discipline and efficiency of our operation.
“Bond/Roberts were now secure in the lead and our other two cars were in the top six. Our last scheduled stops went according to plan and Bond cruised home to victory, with Bruce McPhee (in a dealer-entered GT-HO) a fighting second 44 seconds behind, ahead of West/Brock in third and Macrow/Woelders in sixth.
“Our tyres were like brand new, the second set of pads in Bond’s car were only half worn and we’d had no fuel problems, as the Monaro’s 25-gallon tank capacity was just right for our pit stop strategy.
“Our drivers had used only third and top gears for the entire race, changing up at 4500rpm so that the engines were at their peak torque each time top gear was engaged. Our 5500rpm rev limit on Conrod Straight equated to a top speed of 125mph (200km/h). We also had an extra 300rpm in reserve if needed.”
So the HT Monaro GTS 350 joined Holden’s long and illustrious list of Bathurst winners in addition to its unique title of being the first Holden – and first Australian car – to win the ATCC. And for that Holden fans will always owe Norm Beechey and Harry Firth a great debt of gratitude.
