First full test of Brock's hottest-ever Commodore Any car from Peter Brocks’ HDT Special Vehicles operation is bound to be a bit out of the ordinary, but the big blue SS Group A Commodore is special even by Brock’s standards.  Bred to win races, it’s probably the most purposeful car ever to come out of the HDT workshops.

It’s 7pm Friday, after a long day at the office battling telephones and deadlines, it’s time to head home.  Down to the garage and pick up the Commodore from the almost deserted parking area.  One pump on the throttle, turn the key, and it fires, settling down immediately to a fast but lumpy idle.  Trickle metres down to the bowser to gas up – there’s only 214 kilometres on the odo, but a fuel gauge showing the 63 litre tank to be two-thirds empty is mute testimony to the capacity of the Rochester Quadrajet to mix vast quantities of high octane and atmosphere.

The night shift is on hand to fill’er up almost before the engine stops.  Only European exotica and Brock Commodores are worth investigating on a cold autumn night…

The decal says it all… Chassis is brilliantly responsive, does exactly what it’s asked to do. A9L version of 4.9 V8 develops 196 Kw, uses L34 rods, big valve heads and extractors.  Look for red block and lots of chrome Sculptured Momo wheel hides minor gauges, but is great to use.  Note left foot rest 16 inch wheels are vented to aid brake cooling.  Were developed specially for HDT Massive single tailpipe is only visible piece of new extractor exhaust system responsible for some of the power gain over SS Group Three.

Tanked up, it’s out into the steady traffic of Friday night traffic.  The V8 rumbles along happily in first and second gear, although it’s clear the valve timing is far from standard, because more revs than usual are needed to get away from the lights cleanly.  Second gear, 3000 rpm, 65km/h.  A gap appears.  A quick dab on the throttle and the gap is filled.  Quickly, cleanly and without fuss.  Red Light, lean forward and turn on the radio.  It’s Eurovox quality AM/FM, but the speakers, one front and one rea, are GMH dreadful.  It’s not worth listening to, so off it goes.  Settle back into the firm, hip-hugging Scheel seat and listen to the mechanical music up front instead. Roller rockers and extractor exhausts hammer a syncopated rhythm.  Under way again and the first impressions are starting to gell.  The suspension is rock hard and not at all suited to tram lines and potholes.  The steering’s heavy – is it power assisted? – and the sculptured Momo wheel obscures the oil pressure gauge and ammeter.  The engine only really starts to come on stream above 2500rpm, but the mid range grunt is simply awesome.  HDT says it will rev to 6000, but it’s hard to imagine needing to do so.  The gear shift is heavy and clunky, but the clutch is surprisingly light.  And everybody’s looking at you.  Men mainly, young to middle-aged, P platers in old Torana’s with fat tyres on chromed rims; truckies in massive Kenworths; suited middle management types in company car Sigmas.  The bright blue paintwork, the wide 16-inch wheels, the Peter Brock decals all signal that this Commodore is Something Special. Women?  They’d much rather have the white Porsche 911 in front and prefer to concentrate their fantasies in that direction.  On the freeway now and up to 100km/h – with bursts to 120 or so to clear past the wombats who insist on hogging the right hand lane.  Take care, though because the gendarmerie tend to long longer and harder than most… A red De Tomaso rushes up from behind to hold station alongside before dropping back slightly to follow astern through the mobile roadblocks.  Just before his exit, the De Tomaso driver again comes alongside, looks then powers off up the ramp.  The quad-piped 351 sounds glorious.  Sunday 8am, winter is near, but the dawn is clear and golden sunlight tumbles through the trees.  In the drive the Commodore awaits, dripping with early morning dew.  Again one pump, turn the key, and the V8 fires first time.  With exhaust condensation filling the rear view mirror while the demister works overtime to shift the mist off the screen, it’s out of town at a rumbling idle.  Four or five kilometres down the road, past the last houses, the screen has cleared and its time to pick up the pace a little.  Not to much, though, for while the car is warming up nicely, the driver is still pretty cold.  On to a short section of dirt with six or seven second gear corners.  Play a bit with the throttle.  Hey!  The tail flicks out instantly as the co-efficient of friction between the rear Bridgestones and the hard packed dirt is instantly reduced to zero by 196 growling kilowatts.  Lift off gently and saw at the Momo wheel and it all comes back into order, however.  Through the small town, past the road works and on to the first run over the ranges.  Time t let off the leash.  For the first two kilometres the bitumen is rough and narrow, although straight.  Above 110 km/h the Commodore is a real handful as it leaps and skitters around the road, requiring constant corrections on the steering wheel to keep it in the right lane.  Back off and it’s just plain rough. Past the rough stuff and the road starts to twist and turn, gently at first, but then gathering itself up tighter and tighter as it snakes down the mountainside.  Although this road is well known, progress is still somewhat erratic. Dammit, the car should be quicker, but its hard work.  Cornering seems to require a higher degree of commitment than the driver is prepared to offer, so it’s point and squirt on this section and the passage of distance is made in rapid time, thanks to the simply effortless power on tap.  At the bottom of the mountain the brakes signal their protest at such hamfisted (clubfooted) treatment by smelling very, very hot and producing a so-so pedal.

Cruise for a bit to the next interesting section, this one unknown.  Reflect on how hard it seems to be to get Mr Brock’s car to go quickly.  A Porsche 944 would have been just as fast with a lot less effort.  At legal highway speeds a cacophony of sound assaults the ears.  The engine, ever present, is subdued by the rush of wind around the A-pillars, the rumble of the wide rubber on the course tarmac, and the whine from the gearbox.  It’s overcast now and the road ahead, lined with tail mountain ash and huge prehistoric tree ferns, is climbing again.The surface is billiard table smooth, the corners of the second and third-gear variety, punctuated by the occasional 500-metre straight.  Try again, this time using the throttle hard to get the car quickly and cleanly out of the corners.

All the action happens above 2500 rpm.  Power allows oversteer to be dialled in with ease – even on dry bitumen!

On the way home and on to the same section of road that proved so hard to get right earlier.  This time, after almost two hours and 200 kilometres at the wheel, the Commodore feels better through the fast sweepers and over the blind crests.  The car hasn’t changed of course – it’s just that the driver is now prepared to trust the chassis a little more and commit it to corners with the decisiveness that appears necessary to make it work properly.  Thus given the rhythm of that tight, twisty road returns and the run home is quicker and much, much smoother than the drive out.  Cruise into town hot and sweaty after a workout that’s been as physical as it has cerebral.  Arms, shoulders and hands ache from wrestling with the Momo and the agricultural gearshift.  Ears ring with noise.  A cup of coffee would be welcome.  Just over 237 kilometres on the odo in tow hours and the fuel gauge reads three quarters empty.  Over a brew it’s time to reflect on the Commodore. 

Clearly this is a car which demands a high level of input from the driver.  Under normal circumstances, it’s totally forgiving and deceptively docile in traffic.  But start to press on and it’s soon apparent that there’s very little sneeze factor built in.  The Commodore will go exactly where it’s pointed, but if the driver points it in the wrong direction it takes a deft hand on the controls to retrieve the situation.  The steering and suspension transmit scores of messages to the driver and any road can be devoured, analysed and instructions encoded to hands and feet quickly enough. 

Thus the HDT Holden Commodore is anything but an average motorcar.  To drive one is a sensory experience of the first order.  To own one is to be one of just 500 people in the country.  The SS Group A owes its existence wholly and solely to motor racing, having been developed to allow Peter Brock’s Mobil Holden Dealer Team to field a more competitive Commodore on race tracks in Australia this year.  as such, it’s probably the most purposeful Holden ever to come out of Brock’s respected HDT Special Vehicles operation.  The need a road going race special has arisen because of a change in the regulations under which Australian touring car racing is run.  No longer are local tin-tops a unique breed – instead they comply with rules laid down by the worldwide governing body of motor racing sport, FISA.  Under FISA’s naming system, tourers are known as Group A cars, HDT has come right to the point with its latest creation.

The SS Group A is a significant car in more ways than one.  Not only is it the first serious attempt by local industry to compete, in any arena, on equal terms with overseas manufacturers, but it also represents overt support of motor racing by General Motors-Holdens.  Mindful, no doubt, of the marketing kudos generated by Brock’s on track representation, the General has made a fairly major running change to its V8 engine and committed itself to producing 5000 V8 engined cars by the end of 1985 to enable Brock to homologate a more competitive race car.  The evergreen 308 cubic inch bent-eight, a GM-H standard since 1970 has been de-stroked to 304 cubic inches – or in metric terms it’s gone from 5044cc to 4979cc by way of a 1mm decrease in stroke.  It’s quite an abrupt about-face from a manufacturer which intended to kill off the V8 altogether when lead free fuel came in 1986. 

But Brock needs to have 5000 V8 Commodores built if he wants to continue racing one.  The 500 SS Group A’s?  They’re what are known as ‘evolution specials’ – cars which take a basic engine and body combination and optimise little things like gearboxes and diff ratios, aerodynamic aids and exhaust systems.  And the switch to 4.9 litres?  That simply means Brock will be able to compete in the up to 5 litre class and therefore discard 75 kilograms of ballast from the race cars – which makes a big difference on the long haul up the mountain at Bathurst.

Lean, mean SS Group A looks much tidier than full-dress SS Group Three.  Rear spoiler won’t be allowed on race cars though.

The result is a car which is one of the few out and out driver’s car still built.  Everything, but everything, on the SS Group A is for a reason.  Inside for example, it’s stark Commodore.  A basic radio, budget carpets and trim, no gee-whiz goodies like air conditioning or power windows, or sunroof.  Sure the front seats are Scheel, with the rear bench trimmed to match in a special HDT fabric, but like left foot rest and the Momo steering wheel, they are there because they hold you in, not because they look good.  By comparison with the full-dress SS Group Three, the Group A (in any colour you want as long as it is Formula Blue) seems a trifle austere.  There are no side skirts, rear bumper extensions, bonnet strakes or scoops – just a wind tunnel tested shark mouth grille, new front air dam and a moderate rear spoiler on the boot lid.  If any Commodore painted bright blue with 16 inch wheels, Bridgestone Potenza 225/50 tyres and Peter Brock decals could hope to look subtle, the Group A does. 

It’s under the skin that really counts with this latest Brock special.  The standard 4.9 litre engine, designated LV2 in GM-speak, uses L34 conrods and develops 117 Kw at 4000 rpm and 336 Nm of torque At 2400 rpm, while the big valve V5H which will continue to be the mainstay of HDT SS and Group Three, develops 126 Kw and 351 Nm at the same engine speeds.  The power and torque figures for both the 4.9 litre engines are identical to those quoted for the old 5 litre versions.  For the Group A, the V5H has received some special treatment.  The valve train includes a Crane high-lift cam and roller rockers, as well as a dual row timing chain.  known as the A9L, the engine also receives a specially cast inlet manifold, a lighter flywheel for quicker response and extractors designed by HM headers which feed the spent gasses into a single two inch tailpipe.  Claimed output of 196 Kw at 5200 is 19 more that the best of the Group Threes at 400 more rpm, while torque of 418 Nm is identical, although the peak occurs 100 rpm higher at 3600 rpm.  The engine drives through old faithful M21 four speed gearbox and the 3.08 Isd rear axle.  The Chassis bits are virtually SS Group Three spec throughout, from the Bilstein gas dampers all round, to the 14 mm rear sway bar, to the massive281 boosted disc brakes on all four wheels.  The front end has been tightened marginally, however, with the addition of a 27 mm sway bar I place of the Group Three’s mm units. 

Bolted altogether by HDT, the result is a family sedan capable of 15.6 sec for the standing 400m, with a 0-100 km/h time of 7.6 sec.  While it could hardly be described as brute force and ignorance, it must be said that the Group A is hardly comports itself in a sophisticated manner.  Driven hard, the V8 bellows lustily and joyfully, while wind, road and gear noise add to the general cacophony of sound.  Rough roads pose a serious threat to loose fillings, while wet ones require judicious use of the throttle to prevent any sudden and unseemly changes in attitude. 

There is not much point in considering whether or not the Group A is worth $21,950.  Either you want one or you don’t.  But it’s not a car we could consider for long interstate trips, it’s simply too noisy, too harsh-riding and, with only 83 litre fuel tank to draw from, too thirsty.  There are other cars capable of coast to coast cruising as quickly and more efficiently and which don’t demand absolute concentration 100 percent of the time to achieve it.  Besides which they would be far less noticeable.  Let’s face it, the Group A is about as inconspicuous as a whore in a nunnery when it comes to highway patrol.  But it’s not meant to be an interstate cruiser.  The Group A is a car to be experienced – and the experience savoured.  It’s a car for early morning blast to clear the cobwebs.  It is, an era when even Ferraris come with automatic transmission and air conditioning, an uncompromising drivers car.
 

It has the racers edge Motor Manual  July 1985

The Best Laid Plans 

Holden the front page!  Just days after we handed back the impressive Group A SS Commodore back to GM-H came the news from CAMS that the HDT hadn’t built enough of the blue bullets to enable homologation to proceed. 

That means that Peter Brock will be forced to contest the Australian Endurance Championship and, more importantly, the James Hardie 1000, in a car that has been running a distant second to the JPS BMW’s and struggled against Dick Johnson’s Mustang and Robbie Francevic’s Volvo 24oT throughout the Australian Touring Car Championship. 

Brock and HDT will go to Bathurst this year with their worst chance of winning since 1977. 

CAMS has accepted the base model 4.9 litre engine, which has a smaller valve LV2 engine and is available with the M21 four speed gearbox, but not the ‘sporting evolution’ Group A SS, which has performance goodies.  This is because GM-H presented paperwork to CAMS by May 28 deadline indicating 500 4.9 litre base cars had already been built and another 500 would be completed by August 1.  (Until 1987 Australian manufacturers only need to produce 1000 base cars of an identical mechanical configuration to qualify for homologation, on top of which the 500 “sporting evolution’ cars, that is Group A SS Commodores in the case of GM-H, must also be built in the same period).  Production of the Group A SS has been delayed, says HDT because of union trouble on the wharves and bans on the delivery of goods to it’s Port Melbourne factory.  Reliable sources say only 106 Group A’s had been built by the deadline. 

Providing that all 1000 base cars are built by August 1, Brock will still be able to trim 75 kg from the racecar and will be allowed to use a five speed Getrag gearbox at Bathurst.  But the 4.9 engine in the base car is only the small valve LV2 unit, so the HDT is on the horns of a dilemma.  The critical factor is the gearbox, according to HDT’s John Harvey.  When the current race was initially homologated, one of two sets of gear ratios had to be chosen for the four speeder.  With long term plans calling for an updated car mid year, the HDT sent for the set of ratios most suited to the sprint races in the Australian Touring Car Championship.  For Bathurst, with its steep uphill climbs and long, long Conrod straight those ratios all but useless. 

HDT will build a new race car with the small valve 4.9 engine, 75 kg less weight and the five speed gearbox and test it back to back with the current car before deciding which way to go on the first Sunday in October.  All is not lost, however.  The high-performance A9L engine, with its cams, roller rockers and extractor exhausts, will be eligible for the track as of February 1986.  If all goes to the revised plans.