69 replies to this topic

[EunUCh]

yeah i like some of that old footage as well,i never had anything to do with the cars myself
but a good freind did have.He was involvded with helping set up an A9x back in the 80s
and from memory the gbox/diff were stock and the drivers had to be carefull with
them,some one correct me if i am wrong.I do remember reading in an old street machine
mag.and vaugley remember seeing an article where they had 2 downdraft webers on some.
not sure about internals but i think early in the peace they had to run the stock single
row timming chain.Hope thats a start,there will be someone here that will know heaps
more about it.

Edited by NOBALLSUC, 30 June 2011 - 06:21 AM.

[Dr Terry]

You could write a whole book on this topic, but I'll try & summarise how it was back then.

Up until 1972 there were 2 categories for 'touring cars'.

At Bathurst & a few other tracks (beginning in 1960 at Philip Island) they held races for 'Series Production Cars'

These cars were absolutely stock except for a few safety items (seat harness, fire extinguisher, roll cage (not all), removal of hubcap, addition of bonnet hold-downs etc.), you get the idea.

Cortinas, XR/XT/XW/XY Fords, HK/HT Monaros, GTR XU-1s all raced in this category.

For the ATCC (Aust Touring Car Championship) also beginning in 1960, but at Gnoo Blas in Orange, they used 'Improved Touring Cars'.

The rules here allowed freedoms to engines, suspension etc. This class was ruled by Jags, then Mustangs, Camaros, & Beechey's Monaro.

As a result of the 'Supercar scare' (Google it) Series Prod cars became Group C with almost as many freedoms as the old 'Improved' category. So in the 1973 Bathurst the Fords & Toranas etc. got bigger wheels & had freedom of suspension, carburettors & camshaft etc. etc. But they still had to be based on a factory built car with a minimum build number. This is why cars like the L34 & RPO83 were produced, these were the basis for early Group C cars.

At this time Mustangs & Camaros etc, were allowed more modifications & became Sports Sedans, with the ATCC now held for the Bathurst type cars.

In the 1973 Bathurst many cars raced were basically 1972 cars with Group C mods. By 1974/75/76 the newer L34 & Ford XA/XB ruled the roost.

When the dreaded ADR27A anti-pollution laws hit the industry in 1976, CAMS allowed both Ford & Holden to run the 1974/75 type motors (L34 & Ford 351 4V) to be used in the later cars (A9X & Ford XC). The factory A9X & XC just came with plain Jane motors, with full ADR27A gear, but at the track they could fit the 'pre-pollution' Bathurst type motor. This ceased for 1980, but by then more & more freedoms were given to the Group C cars, with the last version being the 'Last of the Big Bangers' Brock VK in 1984.

The A9Xs raced with modified hi-po L34 engines & BW Super T10 gearboxes neither of which was ever factory fitted, however the T-10 was listed as a dealer option to satisfy the rules.

In 1985, Group A was introduced which allowed more freedoms in some ares than Group C, but was more restrictive in the engine area. This is where the single row timing chain was an issue. You had to race what the factory fitted in that area. Group A was an international formula, so this allowed Jags, Sierras & finally the Godzilla GTR Skyline to race. Many punters liked this mix many more did not & voted with their feet. By 1989/91 touring car racing had reached a low in spectator numbers, so for 1993 they introduced the new V8 class. This was more popular & by 1997 the category became V8 Supercars with a huge marketing push by IMG Sport. The rest is history.

Dr Terry

[micklx]

Good rundown Dr Terry.
I'll just add that in 1985 Brock was working on the VK Group A (Blue meanie) this car had a stronger engine with more power, double row timing chain etc, unfortunately it wasn't ready in time or they didn't sell enough, can't remember exactly. So many Commodores ended the race with broken timing chains including Brock who was in 3rd place and charging hard with only a few laps to go. By 1986 the VK Group A was a well developed car and Gricey won with the 2 HDT cars in 2nd and 5th from memory.

[Dr Terry]

Good rundown Dr Terry.
I'll just add that in 1985 Brock was working on the VK Group A (Blue meanie) this car had a stronger engine with more power, double row timing chain etc, unfortunately it wasn't ready in time or they didn't sell enough, can't remember exactly. So many Commodores ended the race with broken timing chains including Brock who was in 3rd place and charging hard with only a few laps to go. By 1986 the VK Group A was a well developed car and Gricey won with the 2 HDT cars in 2nd and 5th from memory.

Yes, the 1985 Commodore was very underdeveloped, the 1985 version didn't get the Blue Meanie's (A9L) upgrades, so raced based on VK 304 Group 3 spec. The 1986 Bathurst car got the A9L upgrades.

However this happened regularly to Bathurst Holdens. The first year wasn't so good, but they came back in the following years in much more reliable form.

Go back thru history & look at:-

1. 1970 LC GTR-XU1
2. 1974 LH L34
3. 1977 LX A9X
4. 1980 VC Commodore
5. 1985 VK Commodore (mentioned above)
6. 1989 SS Group A Commodore (Walky)

All the above were embarrassing losses in cars that could've/should've won, but the following year(s) were more successful.

Dr Terry

[Dr Terry]

Dr Terry I agree in the majortity of cases the first year of a new car in competition has been met with little success as you noted the L34 and A9X struggled in the first year but dominated in the two years following there introduction. However I dont know why you listed the VC as it won everything in 1980 Touring Car Chanmpionship, Sandown, Bathurst, and the Endurance Series.

Great discussion guys.

Sorry, typo. I meant 1981 VC. In 1980 he had the goods on the opposition, what there was of it anyway.

1981 is when CAMS wouldn't let him run the VC Brock goodies, he had to run small valve heads etc. or run the full weight SL/E with a/cond & electric windows etc if he wanted to run the big valve heads. That year the XD had all sorts of 'funny' bits.

Dr Terry

[Potta]

The race in '85 is one of my earliest memories of Bathurst.

I was about 8 years old and remember cheering Brocky on cause he was on a charge, and then his timing chain broke...doh.

[micklx]

My first visit to Bathurst was in 1987, the World Touring Car race, it was a fantastic race, despite the politics. I went back the following year and all the top Walkinshaw model Commodores broke down, from memory 2 Corollas finished in the top 10. Not a great race at all.

[Potta]

What year did Brocky get a broken windscreen and then they made him pop out the back one too?

That must have been 85 or 86??

I remember that pretty vividly too.

[Potta]

What year did Brocky get a broken windscreen and then they made him pop out the back one too?

That must have been 85 or 86??

I remember that pretty vividly too.

[REDA9X]

I remember that 85 race well. The team removed the front windscreen as Brock could barely see coming down pit straight into the sun, he then put on John Harveys full face helmet. They were then asked to remove the rear screen. Brock raced back in, Marty Watt kicked the window out swinging off the bars and Brock then chased down 2nd and passed but he pushed the engine just that little bit too far pulling out of the slipstream of second and the timing chain packed it in.

As for the original question, the cars were much closer to what you could buy off the showroom, but still very modified.
The common story people get is the A9X race car ran the L34 engine, not technically true. When the A9X was released it was an evolution from the L34 (talking road cars here)and all the bits that were in the L34 were already homoligated for racing, so all the A9X really needed was a few extra bits to fix the issues they had with the L34, namely brakes, gearbox and diff. There were other improvements over the engine used in the L34 for race cars too, new crank, no engine driven fan and the bonnet scoop to allow the downdraft Webers to be used.
But what could you change from a road car? Well obvious stuff like bolt in a cage, engine improvements (the L34 in race trim put out 350Hp on a good day, by the end of the A9X they were pumping out just under 400Hp). Brake diameter couldnt be changed but you could use thicker discs and race calipers. Trim had to be in the car, the T10 gearbox was used over the flimsy M21 in the road car (T10 was a dealer option on the road A9X). The diffs were not that much different from a road car, but by 1979 HDT were now using full floating hubs. Tanks were a 140l drop tank, but you only really needed that for enduros and by Sandown 79 they had to have a dry brake system fitted. Springs, shocks wheels, sway bars etc were all free, but you were not allowed to cut anything to make stuff fit, this was already done on the road cars so race cars could fit the big rubber. Like DR Terry said though you could write a book on it.

[REDA9X]

Yeah, and I'm sure your L34 HO is not as it came off the factory floor nor would it comply with the CAMS regulations of the day.

[REDA9X]

If it's as retired it may well have been raced either during the A9X years, or maybe in other classes beyond that. What I was saying was the L34 in race trim in the days they were raced from 74-77 peaked at around 350Hp. Now, there would have been teams that continued to race L34 while everyone else moved onto A9X, and then some people raced these cars in various classes years later. The engines would have continued to be developed from what they were at the peak of L34 development. 420Hp out of a 308 under Group C regulations was about the limit they were ever developed to though in the "last of the Big Bangers".