The Holden Commodore has become the favourite car in Australia to modify. Available over the years with engines which have ranged from a Starfire four cylinder (best forgotten!) right through to the multi-point EFI 5.7 litre V8 from HSV, the diversity of engines and bodies means that whether your budget is $1,000 or $50,000 there's a Commodore to suit. In this feature we'll be concentrating on the cars available for under ten grand - budget performance which can still hold its head high in go, whoa and handling.
Commodore History
The first Commodore was the VB, released with a huge fanfare in November 1978.
Originally developed from a German Opel whose design was started by GM in 1971, the Commodore combined a much more modern body design than the 'H' series full-size Holdens, while still using the venerable six cylinder and V8 engines.
With Holden simultaneously selling the Torana, the Commodore and the HZ Holden, there was an obvious overlap in terms of the models available. Holden was unsure whether the Torana or HZ would be killed off, and time proved it to be the six-seater Kingswood which first bit the dust.
Engines used were derived from the previous Holdens, with 2.85 and 3.3 litre sixes, and the 4.2 and 5 litre V8s. Trim levels for the VB comprised the bare Commodore, the SL and the SL/E.
The SL/E was very well endowed with equipment, even to the extent of having headlight wipers - a feature not seen on an Australian car before or since. The first Commodore had a fussy grille with the Holden badge mounted at the top, and just under 96,000 VBs were built.
1980 brought the release of the VC, which body-wise was a minor face-lift characterised by an egg-crate grille. It also introduced the four cylinder engine, which was basically a traditional Holden six with two of the cylinders cut off! While the Commodore Four featured a different cam and carb to the Sunbird, it was still a case of too much car and too little grunt.
The six and eight cylinder engines in the VC were the revised 'XT5' versions, which boasted increases of 25 per cent in power, while at the same time giving better economy. This was achieved by the use of electronic ignition, and a redesign of the head, carb, cam, inlet and exhaust manifolds. However, the comp ratio was down. Over 109,000 VCs were built.
The next Commodore - no, not the VD but the VH - was launched in 1981. It can be recognised by its use of a grille using thin horizontal slats. An extensive range of cars was available, with five models, five engine options and four transmissions to pick from.
The latter included the first five speed box to be sold in a Commodore. A long options list included niceties like central locking and cruise control, as well as Holden's first trip computer. Over 141,000 VH models were sold.
Featuring an extensive styling overhaul (a response to criticism that the previous models looked too similar), the VK was released in 1984.
Six window styling, a slatted bold grille, plastic bumpers, and optional EFI on the six all meant that the VK was a substantial upgrade over the VH. With the release of the VK came new names for the different trim levels - SL, Berlina and Calais replaced the previous nomenclature.
The Calais was fitted with an electronic digital/analog instrument panel - the first in an Australian-built car. EFI was an option on the 3.3 litre six - but came only with that engine tied to the Trimatic auto.
However, fuel injection did lift the power of this engine to 106 kW without loss of economy.
1986 represented the biggest jump in mechanicals and styling of the Commodore series up to that time. The coming of unleaded petrol meant that Holden had to retire the faithful six which had served it so well for so long.
In its place was a radical change of pace - a Nissan SOHC alloy-head 3 litre six, with full engine management on all models. The transmissions, too, were Nissan - either a five speed manual or the much more common 4-speed overdrive auto. The new engine gave 33 per cent more power and 15 per cent better fuel economy than the previous larger 3.3 litre engine.
In the second half of 1986 the factory Turbo model was released, which brought stunning performance to the car. Following it came the revised-for-unleaded 4.9 litre V8, which was - however - slower than the Turbo - even in Brock form.
The VN went on to replace the VL, and brought with it the Buick V6 and a totally new body. Aussies loved the new 3.8-litre injected V6 with its excellent torque and instant response. The VN was also externally and internally a much larger car - and Holden's advertising campaign pushed that point. The all-new-for-Australia car also sported improved suspension design and greatly improved aerodynamics.
The interim Nissan engine was replaced by a compact iron-block-and-heads 3.8 litre V6, developing 125kW from its advanced GM-Delco engine management system.
The TH700 4-speed trans replaced the Nissan-derived transmissions and gave the car lazy cruising revs.
The first major update of the VN was the VP model, which was born in 1991. This model dealt with the first of the large-series car's teething problems, which had included engine harshness and noise. An IRS option became available on the Executive, Berlina and standard on the Calais. A remote central locking and anti-theft system also became standard issue at this time. Overall, it was a much more refined vehicle than the VN.The VP can be picked from the VN model mainly by its different grille and tail light trim panel.
In 1993, the next update - the VR Commodore - was delivered into the showrooms. However, because these cars - and all those that followed it - are above our $10,000 limit, we'll stop at the VP.
Brock Commodores
While the Brock Commodores are usually going to be above our ten grand limit, they're worth covering because the mods made by the HDT organisation can be copied to achieve similar results at a much lower cost than finding a genuine Brock. Plus, there's an awful lot of bullshit associated with these cars and their performance, so it makes sense to look at what they actually comprised and what they could do.
The first of the cars was the late 1980 VC (which was available in only white, red or black) which could run a 16.1 quarter. That means, incidentally, that any bog standard VN V6 would give one a run for its money... Engine mods comprised a matched inlet manifold, ported heads with larger valves and a high capacity air cleaner. Unwanted gases escaped via a dual exhaust system. However, lower gearing was responsible for a large part of the performance, with a 3.36 final drive used in the manual cars. At its top speed of 210 km/h this meant that the engine actually needed to pull higher-than-recommended revs. The suspension used re-rated coils all round and Bilstein gas shocks at the back, while brakes were 268 mm ventilated discs at the front and 258 mm solid discs at the rear.
The VH model Brocks were released in the last half of 1982. While available in different levels of development, the majority of those produced were the Group Three 5 litre. With a claimed 184kW at 4750 rpm (versus the VC's 160 at 4500), the Group 3 broke into the fourteens over the standing quarter.
The manual cars managed 14.9 seconds, and could get to 100 kays in 6.7 seconds. Top speed, though, was still the same as the first Brock at 210 km/h.
Working out what modifications were made to the cars is made more difficult because of the mix of options that the customer could select from. Depending on whether they specified Group One, Two or Three (or a mix!) the car could end up with a range of changes. In summary, each level gave the following:
Group 1 - Modified suspension, high-capacity air cleaner, heavy duty brake master cylinder, 70-series Uniroyals, sports steering wheel, gearknob and decals.
Group 2 - had all of the above, plus: blueprinted cylinder heads, extractors, chromed engine parts, a gas-flowed inlet manifold, front guard 'wind-splitters', a rear spoiler and Group 2 decals.
Group 3 added 'further blue-printing of the engine and ignition', 60-series Uniroyals on Irmscher 15-inch alloys, front spoiler, side and rear skirts and Group 3 decals.
While the VH Group 3 was the fastest of all the mainstream Brocks, the VK Brocks - available as a VK SS Group 3 and then later as the blue-only Group A - still had respectable performance. The engine performance modifications of these cars was little changed from the previous models - given legal requirements and the fact that the formula was working, there was little reason to change. The heads had their ports enlarged and combustion chambers cleaned-up, bigger valves were also added. Port-matching of the manifolds was carried out, and a cold-air intake was adapted to the carby. Standard fitment was the four-speed Borg Warner, although the 5-speed was available as an option. While the suspension used Bilsteins all round and a heavier-than-standard front sway bar. The tyres by this time went with Pirelli 225/50 P7's fitted to 16-inch wheels.
The VK Group 3 claimed 177kW at 4800 rpm, down over the VH by 4 per cent. A 3.08 diff (the same as on the VH) was used, and performance had slowed to a standing quarter of 15.7 secs. The VK Group A, released just six months after the Group 3, used a lower compression ratio engine - down from the Group 3's 9.2:1 to 8.8:1. Interestingly, despite this change, power was up - to 196kW. The lower comp ratio was as a result of destroking the engine slightly to allow it to comply with international Group A regs. The engine needed to have a volume of 4.9 litres, and this was achieved by shortening the stroke from 77.8 mm to 76.8 mm by the use of a specially-machined crankshaft. The power was more than regained by the use of Crane roller rockers (which increased lift by running a different-to-standard ratio as well as reducing friction), using a hotter cam, porting to the max, and using tubular headers. L34 rods were used for strength, a double row timing chain gave reliability, and a lightened flywheel aided the engine's responsiveness. As a result of these engine mods, the Group A Brock could lay down a quarter in 15 seconds dead, get to 100 in 7.0, and go onto max warp of 215 km/h.
In the cars that we're covering, the final Brock (not the Walkinshaw) was the Permanent Red VL Group A. However, any analysis of this car is tempered by the fact that the standard ex-Holden Turbo VL was quicker than the Brock car. In fact, the test figures of the Brock Group A show it to have only a 15.9 second quarter, while a base SL manual Turbo could just get into the fourteens! Obviously the halcyon days of the very quick Brocks were gone.
Buying a Used Commodore
In terms of build quality, the worst of the models is the VK, which - according to some sources - were poorly assembled. When buying used, make the normal checks for oil leaks and odd mechanical noises, with a high kilometre car more likely to need expensive maintenance of the brakes and suspension. If you intend to replace the engine, though, it can sometimes make sense to buy a car with high kays because you'd expect to pay a lot less for it. In all cars look for records which indicate that the car has been dealer-serviced, and also check that the factory oil filter has been used. Bottom-end noise in some VKs can be traced to using non-genuine oil filters.
Rust is not normally a problem in Commodores, but check the bottom edges of the doors, the sill panels, the lips of the guards and the boot lid. In an older model accident damage is quite likely, and so check carefully for discrepancies in the paint match between different panels, over-spray on the rubbers, and use a small magnet to check for bog.
Make sure that you lift the carpet and check for cracks around the seat mountings, and that the carpet and underfelt isn't wet. Commodore boots often leak, which can promote surface rust in the boot floor.
Amongst the best of the cheapy Commodores to buy is the VL six. In terms of engine refinement, engine life, fuel economy and smooth grunt the Nissan six is a gem. Effective modification of this engine isn't all that hard, either. The Turbo models are something else again - if you've the odd $5-6,000 handy then up to a genuine 500hp can be gained! With a bit of looking, an atmo VL six should be obtainable for $4,000, and a Turbo model for about $1-2000 more. If you're tempted by the VL V8, don't get too excited. Ex-factory these were quite slow for their thirst - a standard VL six has about the same on-road performance, but with better economy. Of course, if you modify the V8...
Because the VB-VC-VH-VK models were available with such a wide variety of engines, swaps of powerplants, gearboxes, diffs, braking packages, dash panels and so on are all straightforward. However, when the VL gained the Nissan engine, some other associated mechanical changes were made at the same time - including a longer rear axle and a larger tranny tunnel. Fitting VL mechanicals to earlier models - like say slotting-in the Nissan six into a VH - means that transmission tunnel changes will need to be made, for example.
Some Commodore factory options are much more worthwhile than others. For example, the sports pack FE2 suspension can be better replicated by using aftermarket bits. Factory LSDs and four wheel discs are obviously good bits to pick up with a used car purchase, though.
If you intend making modifications, the VN-onwards models are a good bet because they feature the GM-Delco engine management system, which - via a workshop equipped with Kalmaker software - is amenable to re-programming. This means that a new cam, increased compression - or even a blower - can all be added and the ECU then re-programmed to run well. The pushrod V6 is a strong, durable engine as well.
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