HDT Group C Commodores

[Angus5]

This is my first entry on this forum and I have a few questions in my bouncing around in my head.

Just lately I have been really enjoying watching old recordings of Bathurst and ATCC both Group C and A on youtube. The racing is fantastic, watching the cars circulate on bouncy tracks, with distinctly more body roll and suspension travel that a modern supercar. It is a joy to watch Brock in an Aussie V8 Commodore clearly out drive every body else.

I was an avid supercar spectator, up until the COTF rules came into place. Racing on billiard table smooth tracks with such taught, exotic suspension minimising any pitch, roll or yaw, I started to lose interest.

Reading an article on how supercars are constructed further degraded my enthusiasm. To quote,

“The bodies have to be moulded to fit the 2822mm wheelbase, the defined engine location, suspension points, front undertray position and rollcage. Not the other way around.”

“The only exterior panel of the ZB racer that is original material and size is the aluminium bonnet.”

https://www.whichcar.com.au/features/anatomy-of-the-zb-inside-holdens-latest-commodore-supercar

Back to the real world of HDT Group C Commodore race cars, I am intensely curious as to how close to stock they were. There is heaps of info on a number of forums about the engine specifications but very little on the suspension, steering or brakes so I genuflect before the assembled experts of this forum and pose the following questions -

Control arms: Stock or adjustable heim jointed?

Front struts: Bilstein

Steering: Stock rack and pinion?

Brake Callipers: Stock? Harrop? Piston number?

Thank you for taking time to read this and I look forward to your answers.

 

[Smitty]

control arms.. std but with rose joints (in some areas)
Struts.. road cars ran Bilsteins (so did race cars)
steering.. rack and pinion (manual originally but many swapped to power after afew years)
brakes.. def NOT standard (large rotor caliper combos with adjustable masters with no booster)
some pics here u might find interesting

Kennedy/Taylor Grpc Commodore
http://www.my105.com/ListingDetails/aid/63786

 

[Angus5]

Cheers Smitty
Just the info I was after and thanks for the link.

 

[bfhoon]

Brock was a master in those things. I love watching him in the vl skating around in the wet on slicks at bathurst. Pushing it to the absolute limit but just enough so he didnt bin it. I still like following supercars but im not the biggest fan of cotf either. At least this year they are removing twin spring dampers as really not all teams ran them and the teams that had the funds to they have an unfair advantage over the poorer teams. H pattern gearboxes to back in the day how easy they have it these days. Still love watching murphys lap of the gods at bathurst in the kmart commodore.

 

[figjam]

Angus5 …. do you buy/read 'Australian Muscle Car'.
There is a lot of reminiscing about builds from drivers and crew regarding the good old days before the SuperGoCarts.
I have a memory from last year, a current top gun driver had a Bathurst(?) lap in an old H pattern gear car, and stated that he had trouble coming to terms with the shift and the clutch.
However, I still admire the drivers' skills, and pace of the current cars.

 

[bfhoon]

Angus5 …. do you buy/read 'Australian Muscle Car'.
There is a lot of reminiscing about builds from drivers and crew regarding the good old days before the SuperGoCarts.
I have a memory from last year, a current top gun driver had a Bathurst(?) lap in an old H pattern gear car, and stated that he had trouble coming to terms with the shift and the clutch.
However, I still admire the drivers' skills, and pace of the current cars.

You wouldnt be talking about scotty would you?

 

[figjam]

You wouldnt be talking about scotty would you?

Don't remember who, or where. Just remember seeing it, and having a bit of laugh about his comments of the 'old' boxes.

 

[Angus5]

I still clearly remember bfhoon, watching Murphy do that amazing lap. Coming through McPhillamy Park and down over skyline had the hairs standing up on the back of neck, it still does. It was a stunning lap to watch and when the final split came up, the time was unbelievable. What caps it off is Murph's reaction and the reaction of all the teams down pit lane, congratulating what was truly a heroic achievement.

 

[Angus5]

I agree with you figjam on the level of drivers skill and the incredible pace of the cars. It truly is world class. More than ever, the drivers are all incredible athletes and the modern super gocarts (as you so rightly put it) are a technical marvel. However this only furthers my appreciation of the drivers in the previous classes, driving what were modified family sedans. This was the reason for my original question.

I suggest the next gen COTF incorporates some fatter rubber perched under fully sick wheel arches. It wont be any closer to stock but it would look the business. Also I will look out for a copy of AMC the next time I'm newsagent.

 

[DerekP]

So while we are on the subject, how close was Brocky's VC Bathurst race car from the road production version of the VC HDT Brock? In terms of engine spec and HP output & drive train (tranny & diff). I am also a little curious as I was 11 when the VC's were racing around Bathurst.