Buying a used Holden Commodore V8/SS VN/VP (1989-1993)

As the VN-VP Commodore SS and related V8 models have aged, they have retained their amazing grunt per dollar value with sometimes tragic consequences for young drivers. Joe Kenwright takes a realistic look at what still can be an exhilarating but always challenging drive

Holden owned the Australian V8 performance market in 1989 after a heavily revised EFI V8 option emerged in March 1989, seven months after the VN launch. It was the most heavily revised production version since Holden's locally developed lightweight cast iron small block V8 first arrived in 1969.

It picked up the sequenced heads with centre plug location, reinforced block with extra ribbing below the head bolts, revised cooling passages and injector mounting bosses from the special Group A race engine of 1988. While it didn't have the twin-throttle body inlet manifold, four-bolt mains and roller rockers of the Group A, it did have A9L conrods, pistons, crankshaft and heavy duty Tri-metal F770 bearings coupled with a proper multi-point fuel injection system with twin plenum chambers. It delivered 165kW/4400 and 385Nm/3600 and with only 1377kg to haul, it was seriously quick then and still is, by today's standards.

As HSV discovered, there was an easy 20kW to be liberated by a proper cold air intake and exhaust upgrades at which point you started to run into the limitations of the local version of Borg Warner's T5 manual gearbox.

It really is a great engine. It sounds like a proper V8 should and pulled like a train from low revs. It even transformed the refinement of the creaky old VN shell which seemed to amplify the standard V6 roughness.

The origins of the VN shell are the key to knowing what you are dealing with. Unlike today, Holden didn't have a billion dollars to develop the full-size Commodore that it wanted for the VN series. After most Holden factories around the country were closed, Holden on a cash-strapped budget took the old four-cylinder Opel Rekord floorpan, adapted the new side panels from the 1987 European Omega/Carlton and stretched the passenger area over outriggers. The extra width of the cabin was hidden by a widened live rear axle that retained the early Rekord's Panhard rod suspension and the front was cleverly tapered so you wouldn't notice the old narrow strut front end.

Opel's more lavish dash was replaced by a plainer Holden version that formed a module with the firewall and was glued in as one component. Clever styling simplified the front and rear with basic grilles that were easily switched along with large moulded fascias.

If this doesn't sound like the perfect starting point for a premium performance V8 model, you would be right. Despite the weight imbalance between front and rear and the different front and rear tracks (1451/1478mm), Holden turned the VN SS into a reasonable driver's car providing you drove it within everyday passenger car limits. Holden held the wheel and tyre size back to 6.00JJX15/P205/65 HR15 as part of a balanced ride and handling package for all road surfaces.

The four-cylinder Rekord suspension, while state-of-the-art when it first appeared in Australia in 1978, depends heavily on its voided bushes and its Panhard rod to hold it together over choppy surfaces. These bushes have cutouts that allow key locating arms to twist easily in some directions but not others. Without them, no Commodore live rear axle suspension can work. Yet they were not developed to take the huge torque of a V8 and they can tear. The Panhard rod which can create a jacking effect in certain cornering situations is also vulnerable to wear in its bushes.

There is a tendency in some quarters to drop the ride height and replace the voided bushes with solids. This might work in containing big V8 grunt for the strip but it can introduce bump steer that can be fatal on uneven road surfaces.

The VP Commodore SS in October 1991 introduced independent rear suspension (IRS) which made a huge difference over uneven surfaces but brought a new set of problems. Because the Commodore's IRS was a cheap adaptation of the old Opel Senator system until the VX Series II in August 2001, it missed out on the extra control arms that Opel introduced in 1987.

This means the VP Commodore SS IRS system is the same as the Datsun 180B, Triumph Stag and the first BMW 3 Series, all of which display the same lack of camber control and splay out the rear wheels when lowered or loaded for extra tyre wear. They also share the same evil handling on the limit after the outside semi-trailing arm can no longer resist sideways cornering forces and begins to steer of its own accord.

Holden managed this by specifying tyres that would force the driver to slow down before this point is reached but grippy, aftermarket rubber on the V8 models can soon overwhelm the bushes in the rear semi-trailing arms. HSV balanced its extra rubber with upgraded bushes until it decided to follow Opel's lead with the first VTII GTS 300 by adding the extra arms. Upgrading these IRS bushes can be worthwhile especially if stickier rubber has been fitted but because they are also vital for absorbing road shock, there will be a loss of ride quality.

The absence of the Opel's extra control arms leaves the VP IRS non-adjustable and some examples from new chopped out the outside tread of the rear tyres. There are aftermarket adjustment kits available. Adding the extra toe-control arms is the ideal solution but it is not an easy upgrade when their length is unique to the VP-VS series and they require special mounting points on the arms themselves and at the diff end. In some extreme cases, the rear diff carrier can crack so it's worth checking this whole area including its mounting bushes and look at the driveshaft joints and boots while you are at it.

The offset for any alloy wheel fitted to an IRS Commodore is different from the live axle when the clearances and location are very different to the live axle model. Look for some serious bodging where owners have tried to get around this on the cheap.

Although the VN/VP front end retained the earlier MacPherson strut design, there was a major change in anti-roll bar mounting and tuning that improved front end bite dramatically. Top strut mounts can be upgraded but make sure that the correct steering parts and ball joints are fitted as they can be specific to the VN or VP. Fitting the wrong ones can generate straight line stability and handling problems.

Apart from the SS, there is also a range of ex-police cars fitted with the V8 and they can be an even cheaper source of V8 performance. There are subtle seating changes, door bins, Calais dome light, special speedo needle and external gauge lighting and a host of other changes to look for with a genuine police special.  

Because not every owner stayed on top of the suspension and brakes which were marginal for the V8 performance even when new, the destruction rate for these V8 models was unusually high and still is. All of these early V8 Commodores require more than an average driver's skill levels to exploit the performance. If a driver is coming straight from a front-drive car, the loss of rear grip under power will almost certainly catch such a driver by surprise especially in the wet.

It might be a lifesaver to study the fundamental differences between driving a front and rear-drive car before sinking the boot into an early V8 Commodore.

Finding a genuine SS in original condition that hasn't faced a major repair therefore won't be easy. Hanging onto it will require some cunning in terms of your own immobiliser and alarm design. This is not a car you would leave in a workplace or railway station carpark all day or parked overnight on the street. Someone will have a go at stealing it just because it's there.

Heavily modified SS examples are not worth much more than any other modified Commodore V8 but a genuine VN/VP SS in factory condition is a real prize today and has the potential to be a mild collector's item. Leave no stone unturned to ensure that it is not a recycled stolen car when stolen VN and VP Commodores were top of the pops for many years running.

Body
>> Starting with a good body is vital as most mechanical repairs and upgrades are straight forward. Few examples remain unmodified. The tendency to lower and firm up suspension can leave flexible VN body shell feeling tired and creaky. Look for stressed rear panels and excessive driveline harshness under load as the V8 is more likely to be used for towing then followed by a period of merciless burnouts.

>> The VN and VS series were still some years away from Holden's latest thermoset enamels. Extra clear in the top coat replicated a two-pack finish but it soaks up UV and needs stacks of polish and undercover storage to head off oxidation on roof, bonnet and bootlid. The old single stage acrylic paint process may still be holding up in the solid colours but neglected metallics can be dull, porous and ready for a respray. Watch out for repairers who have used modern two pack paints generating a huge difference in shine between original and repaired panels. Replaced plastic bumper sections will often not match in colour.

>> Nasty replica parts including faded tail lights and dud headlights can ruin appearance. Add up the real cost of sourcing genuine parts especially special SS body parts, wheels, decals and badgework.

>> Some cabin plastics and switch gear were basic quality so check all interior fittings. Odometers can fail so a low speedo reading needs to be backed up by genuine records. Make sure that all the distinctive SS interior items are present including trim and instrument pack. Check for broken or bent seat frames and worn fabric near entry points.

>> Although the V8 was improved remarkably for the VN, it could still suffer from bore distortion and cooling problems from flashing left over from the casting. A full compression check is vital.

>> Listen for a noisy fuel pump. Check that all hoses, fuel lines and belts are in top shape.

>> Cooling system was marginal under tough conditions when this body style didn't have enough under bonnet air-circulation in standard form. Late model Falcon thermo fans (wash your mouth out) are a cheap and popular upgrade. Rear main seal will weep but can turn into full blown leak.

>> The VN/VP hydraulic auto transmission was more reliable than the first VR electronic boxes but can be ready for a refresh around 150,000km. Torque converter upgrades and auto mods are common and can destroy or improve the integrated feel of the original.

>> Make sure that any engine overhaul was done by someone who knows what they are doing as computer changes, injection upgrades and camshaft changes all need to be co-ordinated.

>> Manual transmission can be tired and noisy. Watch out for a slipping clutch or excessive effort.

>> Power steering can leak. Listen for noisy pump under load.

>> VN: Broken voided rear suspension bushes, sloppy centre tail shaft bearing and UV joints, worn Panhard rod bushes can generate rear steering and excessive driveline harshness under load. Solid bushes in the wrong places can generate nasty bump steer on choppy surfaces. Listen for diff whines and check that the LSD still works with minimal lash.

>> VP: Semi-trailing arm and diff mounting bushes must be in good shape. Rear hubs and alignment can be destroyed after big lose into a kerb. Driveshafts are durable but won't survive losing their grease through split rubber boots.

>> Quality tyres are vital with the power and light rear end.

>> Superficially repaired insurance write-offs and recycled stolen cars are a real trap. A vehicle security check won't be enough to uncover a stolen car that is wearing the identity of a wreck so look for any inconsistencies in specification and history. 

VP Warning: There is a dangerous tendency for some backyard repairers when switching body shells after a major crash not to transfer the ABS brake system while creating the impression that it is still fitted. If ABS is supposed to be fitted to an example under consideration, check that all components are present and hooked-up.