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Group C Big Banger Spec Help

Discussion in 'VB - VK Holden Commodore (1978 - 1985)' started by Retro Boy, Mar 11, 2016.

  1. Retro Boy

    Retro Boy Time Traveller

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    Currently building a standard VK with Group C Big Banger running gear.
    So it will kind of look original on the outside and interior, but perform as a bit of a racer.
    My subtle tribute car.
    I know the specs of the suspension and wheels / tyres, carby, diff and trans.
    As far as the heads and manifold go, were they Brock heads or were they Yella Terra?
    He did some ads for Yella Terra, so I'm suspecting they may have supplied him with the heads.
    And the intake manifold, was it the Brock one modified with a plate to suit the webbers?
    Last question, sorry guys, anyone know where I can buy the metal, not HDT (fibreglass) proper Group C (Commodore Cup) cold air tray from?

    Many thanks for any advice.

    P.S. I picked up an original Saas Euro in mint condition, same type that I think Gricey and used even Johnson used in the early 80's.
    Anyone remember those Saas Euro wheel ads :)
     
  2. Retro Boy

    Retro Boy Time Traveller

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    Anyone know, at all? :(
     
  3. immortality

    immortality Moderator Staff Member

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    The Brock forums would probably be the best place to ask these sorts of questions.
     
  4. Freedon

    Freedon Member

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    the originals were b-cast heads, i think they were originally machined by yt ( which would be the closest you'd get to them these days )
     
  5. Lacksballs

    Lacksballs Active Member

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    Facing of the cylinder heads was permitted provided the final dimensions are within the manufactures tolerances, and the resultant combustion chamber capacity is not less than that specified in the "Recognition Document". Piston assemblies were free but the compression ratio must not exceed 10.5:1 or the ratio specified on the relevant "Recognition Document". Exhaust system & camshaft were free components (roller cam followers were not permitted, valve head diameter & seat angle had to be the same as the standard component), Crankshafts were free except that of the stroke, phasing & travel must be as on the original crankshaft. The inlet manifold had to be a standard factory component (all as per CAMs Group C Production Touring Cars rules valid 31/12/1984), carberation was a free component hence why HDT went for a pair of webbers, the front carb was set facing slightly forward & the rear slightly back to improve the air flow into them utilizing a custom cold air tray with a simple gauze. Unsure who made the adaptor plate to accommodate the webbers, good luck.
     
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  6. Craig Steven

    Craig Steven New Member

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    What were the specs of the wheels ie: width and backspace?


     
  7. bfhoon

    bfhoon Member

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    Why dont you just sell your house or take out another huge loan and goto the auction happening at bathurst and buy the original vk big banger brocky raced at bathurst. I have a feeling this car will collect some massive coin as well as his toranas. Nothing better than having the realt thing. Ive pondered the idea but the mrs isnt keen at all.
     
  8. Lacksballs

    Lacksballs Active Member

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    I did some research prior to building mine (I've built a road car version), wheels & tyres are the hardest parts to find or replicate.

    From memory I thought HDT used 16x10 Momo AP racing rims on the VK Group C day-glow cars & painted them white, I couldn't find anything similar at the time in Australia so elected to use 15 inch Weld ProStar 15x10 rear & 15x8 front (imported from the US, multiple copies available as well), tyres are the next headache as 15 inch tyres sizes are limited compared with the early 80's. I ended up using 265/50 rear & 225/60 front but could have gone with 295/50 on the rear. A mate of mine built a replica VK 05 race car and got set a of used 15" slicks off a "muscle car".

    Some have had rims specially made in the $1,500 - 2,000 each range ($6-8k), that way you can specify the backspace & diameter.

    Rear prior to powder coating:
    IMG_0165.JPG
    Front powder-coated & decals:
    fullsizeoutput_117e.jpeg
    Mine finished:
    fullsizeoutput_1de8.jpeg
    Actual 05 race car:
    IMG_0026.JPG
     
    Last edited: Jul 31, 2018
    Deuce and VS 5.0 like this.
  9. bfhoon

    bfhoon Member

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    Those wheels and flares look hot. The rear bar look a tiny bit awkward but you dont notice it as much on the race car probably due to the colour and art. Very tidy and tuff
     
  10. Lacksballs

    Lacksballs Active Member

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    When you're driving it & look out the rear window it doesn't look tiny!!!!

    fullsizeoutput_3812.jpeg
     
  11. VS 5.0

    VS 5.0 Well-Known Member

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    I think @bfhoon ws talking about the rear bumper bar, not the rear wing.
     
  12. Lex

    Lex Active Member

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    He isn't saying the rear spoiler is small (tiny). He is saying, it looks awkward? (slightly (tiny) strange?)
    I wouldn't have thought you would be able to see the rear bumper while driving it?
     
  13. VS 5.0

    VS 5.0 Well-Known Member

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    BTW @Lacksballs , I've probably said it before somewhere, but I will say it again....love your car.
     
  14. Lacksballs

    Lacksballs Active Member

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    That makes more sense, getting the rear bumper to "cut" into & around the rear flare was a real mission. I wanted to keep the flare & bumper both bolt on rather than using a urethane style sealant to adhere & fill any small gaps. So I needed to have a small gap to allow the bumper & flare to move independently of each other without rubbing the paint off. If you were to glue, paint then wrap the car in "Marlboro" decals it would hide a multitude of imperfections.
     
  15. Reaper

    Reaper Tells it like it is.

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    Possibly the best close match wheel I have seen for these.
     
  16. bfhoon

    bfhoon Member

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    Thats what I meant the rear bumper. Still looks tops and tuff as love it.
     

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