Great Thread, Group A was IMHO a far better (but flawed) formula than the current formula yawn sillouettes (V8 Supercars and the like) but here are a couple of points to ponder
Group A rules required 25,000 units be built in a single year, from which a minimum 2,500 of the competing model must be produced (unless Australian made, then the number was just 1,000). Additionally, a homologation special could then be released, of which only 500 cars were required.
This was correct for Group A rally cars, but for Group A touring cars it was as follows:
Group A rules required 5000 units ("base models") be built in a single year, (unless Australian made, then the number was just 1,000, but the cars could only race in the Asia-Pacific region, for International racing, read Europe, Australian manufacturers still had to build 5000 base models). The "base model" had to have the same capacity/configuration. ie you couldnt build 5000 cars, 4000 of them hard tops and 1000 of them soft tops and count them as the same for the 5000, also the engine had to be the same configuration, ie if 4000 were a straight six and 1000 were a v8 then they were not considered 5000 base models, eg BMW had to build 5000 six cylinder 3.5 635s in the space of one year, Holden had to build 1000 5.0 V8 commodores in the space of one year to race in Asia-Pacific or 5000 in the space of one year to race Internationally. Additionally, a homologation special could then be released, of which a minimum of 500 cars were required (but didnt have to be actually "sold", more of which later).
From early 1985, the Holden Commodore was forced to run a minimum weight of a porky 1,400kg, but with the release of the partially approved Group A evolution model, featuring a very slight engine destroke from 5044cc to 4,987cc, the Commodore teams could now race to a much more competitive 1,325kg
Partially correct. The previous porkydore was homologated based on the 1000 build rule, using the Commodore 5.0 SS with large valve heads (but no roller valve train, aero package etc etc) as the base car. The destroked more competitive 4.9 SS commodore was a new 1000 minimum build homologation, and definately not a "sporting evolution". Unfortunately being a base car it was homologated with small valve heads, no roller valve train, aero package etc etc. On the one hand the 5.0 SS had the big valve heads and hence more HP, but it had to weigh 75KG more. The 5.0 SS was also homologated with a four speed gearbox. Gearboxes were technically "free" ie unlike the engine they did not have to be the same unit fitted to the road car, but they had to be the same configuration and actuation, ie if the road car had a H pattern floor shift then so must be the race box, and hence not a sequential, or a paddle shift, and the gear ratios had to homolgated for approval also. The 4.9 SS was homologated with the Getrag 5 speed and a wider range of ratios, so on the other hand it was lighter, but less powerfull, but had a better range of gear ratios available. Most Australian teams opted for the 4.9 SS as soon as it was available, but most had trouble getting the Getrag because they had to go through Brock to get one, Brock had made a "group buy" deal with Getrag to get the best deal for the Australian teams but the German manufacturer was slow on delivery, and naturally he kept the first couple that arrived for his team, as most people would I guess, but the way it was handled did piss off a lot of the teams
The 4.9 SS Group A, a 500 build sporting evolution, was planned for homologation in the first week of september 1985, but it did not eventuate until Dec 1985, mainly due to Victorian wharfie industrial disputes preventing the HDT getting the evolution parts needed to build the 500 cars, these parts being mostly valve train components imported from the USA. One week before the September FIA homologation date deadline the HDT had only built just over 300 cars, and an appeal for a special consideration for "Australia only" homolgation was made to CAMS to allow the sporting evolution to run at Sandown and Bathurst, but this sort of thing was exactly why CAMS went to Group A in the first place and wanted to be rid of, so it was rejected. Hence the rocker saga that plagued the commodores at Sandown and the timing chain failures at Bathurst. Something you may not be aware of, Walkinshaw on learning that the HDT had approached CAMS for special consideration publicly stated:
If they allow those "Hot Rods" to race at Bathurst then we wont be coming
which was hypocritical (more of which later) and was probably another reason why CAMS didnt cave it to the HDT's request.
The Holden Commodore 4.9 SS "base model" was also homolgated under the 5000 build rule in Dec 1985 hence also making the "sporting evolution" eligble to race anywhere in the world, clearing the way for Brocky and Gricey to take on the Europeans on their home turf.
The Volvo 240T model had raced in both Europe, Great Britain, and Australia under a cloud of controversy, after Volvo built the required 500 homologation specials with rear spoiler, larger turbo, intercooler and water injection, to qualify for Group A, then promptly converted 477 of them back to standard 240 spec once approved.
Volvo pulled a swifty on the homologation of the sporting evolution. The rules made no mention of a need for the cars to be sold to the public. On inspection of the 500 cars in the USA the front row of cars were all assembled with the good bits, further back in the rows the cars had the sporting evolution parts sitting on the back seat and in the trunk! For reasons only known to the FIA inspectors this was deemed as ok, but once the competing manufacturers found out the shit started to hit the fan, remember that up until then, not many manufacturers had built a full on sporting evolution, most cars racing were "5000 build base models" and they saw this as playing unfair. It finally came to head when FIA learnt that Volvo had returned most of the cars to standard and sold them standard. FIA requested proof from Volvo of a list of registered owners of the cars. When no registered examples in the USA could be found (two road registered sporting evolutions in Sweden belonging to Volvo exectutives were "found") FIA ordered the car's sporting evolution was "not in the spirit of the regulations" and were hencefore illegal, but Volvo protested the fact under technicalities of the wording of the regulations and won (when it comes down to it, Volvo saw a weakness they could exploit and they played it, but they did nothing illegal).
The Volvos configuration was ideal for the formula, despite their boxy unaerodynamic appearance they had a good chassis/suspension and a strong reliable engine package. (If anyone doubts their chasis, then consider this, in the 1986 James Hardie shoot out, the volvo was 19kmh slower down conrod than the Grice Commodore, 12 kmh slower going up mountain straight but still managed a 2.19.5! Most of the time was gained over the top)
With the inadequate 1.4 weight factor for turbo cars the Volvos (and later the Nissans) had a clear power to weight/tyre size advantage. There was a lot of ridiculous accusations and pit talk in Australia of them cheating in 1985 when they blowing everyone away down any sort of straight (including a bedazzled Dick Johnson in his V8 Mustang) and with them staying with the best cars on the twisty bits, there were even absurd rumours of hidden NO2 tanks in the roll cage, but the fact was the Volvos could be built to the minimum weight, and the capacity/weight/tyre width rules gave them their advantage. Volvo knew that that would end in 87 when the weight factor was changed to 1.7 so they pulled the plug whilst still successful. smart move by them.
(speaking of weight, who remembers the sporting evolution light alloy trailing arms failing in the 1986 Bathurst race, and John Bowe quipping that a standard steel Volvo part would never had failed)
Steve, yes I was, however Petch sold his interest in the LHD car I think after the 2nd round of the '86 ATCC and John Sheppard assumed control of the team known as Volvo Dealer Team. He obviously brought in some of his own troops but the majority of the guys left.
I can't quite be sure on this as it was a long time ago, maybe Frosty5 can confirm it or not but I seem to recall Mark Petch initially contract Les Small of Roadways to manage and run the 1986 car, and it won on it's first outing at Symmons Plains. It was either after that success or the following round that the team was sold and Les Small went back to building customer Commodores. There was quite a bit of disharmony in the Volvo Dealer Team that eventuated when Sheppard took over
