Big banger bodywork

[Nick Short]

Can anyone tell me why, if there was so much fuss about Moffat's Brut 33 XB having slightly different wheel arches to accomodate marginally bigger tyres, that the Falcons and Commodores from 1980 onwards had enormous arch flares. I had always thought that they ran to the same Group C rules, but clearly that isn't the case. So what rule changes came in after 1979 and prior to 1980?

[Shawn S]

Hi Nick,
Basically it was the change of models (A9X Toranas to Commodores and XC Coupe to the XD sedan) in 1980 that caused the bodywork rule changes. Car builders found that the big tyres wouldn't fit on the new cars so the bodywork rules were changed to allow the larger tyres on both makes.
The full story probably goes deeper than this but it's all I can tell you without delving through all of my books and magazines.
Cheers
ShawnS

[Graeme]

Hello there Nick ; I think the boys talking about ugly Brut 33 flares were referring to Moffat's Boss Mustang and not his XB Falcon touring car.

As the Texaco Sierra team found in 1987, touring car regulations are firm on bodywork issues, so I doubt if Moffat modified wheel arch shapes on his old Falcon Hardtops.

Shaun is on the right track about the change in touring car regulations in 1980. The A9X had factory fitted flares on the road car and the XC Hardtop simply had roomy wheelarches. With the adoption of four door bodies in 1980, specific aero packs were homologated for the Holden and Ford racing cars which did not feature on the road cars - specifically front and rear spoilers and wheel arch flares.

[Nick Short]

Thanks once again guys! I thought there had to have been a good reason for Falcons and Commodores to suddenly appear with such enormous arches and spoilers, especially as even the Brock body kits available for road Commodores had nowhere near as big arch flares.

Graeme, if you have a squizz at issue 4 of AMC magazine they mention the fuss over Moffat's 1974 Brut 33 XB arches, which differed from standard by only a small amount but enough to fit wider tyres. There was a protest by HDT which wasn't upheld, especially as Ford weighed in with the statement that the variation was within production tolerances or somesuch! So clearly back then the rules were pretty strict (unless you could find a way round them...). With the RS500s you guys were running under Group A regs, which were very rigid indeed (unless etc...!) so the Texaco Sierras fell foul for being naughty boys. And quite right too. But as issue 1 of AMC reported, Dick Johnson "accidentally" had the homologation weight of a 6 cylinder XD Falcon put down in the CAMS book, with the lucky result that he could strip down his V8 Tru Blu to match that weight, so it's not a new thing...