Group A Ford Sierra RS500

[davyboy]

Thanks for that Conrad.

[Jesper OH]

I'm quite sure that a full homologation of an evolution - i.e. the RS500 Cosworth vs. RS Cosworth, the Commodore VL vs. the "TWR wings and skirts" - would require at least 500 units and that a new evolution could only be homologated after a minimum 12 month period after the most recent evolution. Hope this explains that part of Group A homologation, but interesting news to me that the detail homologation happened as explained in the previous posts. Thank you very much for that.

Jesper

[chunterer]

I can only repeat what davy and jesper have said Conrad. Very revealing post and that bit about the M3 homologation booklet really is fascinating.

No wonder Group A bit the dust in thend end if so many parts were available to use for such a specialist car (you would've thought that flexibility would've made it cheaper!) I guess privateers had a choice of things to use to fit whatever they could afford and the same presumably would've been true for an RS500 runner or a BMW 635 runner before that?

[davyboy]

Originally Posted by Jesper OH

I'm quite sure that a full homologation of an evolution - i.e. the RS500 Cosworth vs. RS Cosworth, the Commodore VL vs. the "TWR wings and skirts" - would require at least 500 units and that a new evolution could only be homologated after a minimum 12 month period after the most recent evolution. Hope this explains that part of Group A homologation, but interesting news to me that the detail homologation happened as explained in the previous posts. Thank you very much for that.

Jesper

Exactly... that's what had me confused as from what I remember all the tweaks to the Cosworth had be consolidated into the RS500 [of which 500 were made], similarly with the M3 Evolution. Maybe that was only the bodywork then.

[PAUL S]

I believe that certain parts had to conform to basic dimensions, but otherwise were free to be modified and further homologated without a run of 500 being made.

As an example the rear beam of the RS500 road car was purely a standard 3dr one with a pair of brackets tack welded on to allow further suspension pick up points to be included for the race cars, all it did was provide a shape that could then be utilised and copied on a race beam, it had no other function on the road cars and could not be made usable as is.

The same with rear suspension arms, UK race cars tended to use modified road car arms but the european cars made use of the more expensive magnesium cast arms which never featured on the road cars at all.

[chavez]

Originally Posted by brown dog

I don't think there was any specific number of these parts required for Gp.A, certainly not 500 or 5000 anyway. It was just the basic road car that had to meet these minimum numbers.

Also some regions, such as Australia, were exempt from the requirement to build 5,000 base cars. Only 2,500 were required.

The best explanation of how the homologation process worked can be found in the '84 James Hardie 1000 Race Programme.

[William Dale Jr]

I though that would only homologate them for use in Australia (and maybe NZ). Pretty sure the full 5000 (plus the 500 evolutions) had to be built before the VK Commodore could be used in the ETCC.

[Jesper OH]

IIRC the Holden Commodore VN only had to be produced in 1,000 examples to be homologated into Group A, but the 500 evolutions still had to be build. I don't know if the 1,000 units also would cover other "specialist" markets, like South Africa, Argentina and Brazil?

Jesper

[anthony81901]

Holden was still required to build 500 evolutions before the model was homologated for competition even in Australia. Hence the 1985 car was basically a road car with slicks and it wasn’t until 1986 that the proper race car appeared. Even though it was ready to race at the beginning of 1988, the debut of the TWR VL was pushed back until August while the 500 were completed.

With less demand for the evolutions in the middle of a recession I recall only 300 VNs evolutions were built when it debuted in 1991. By this stage whilst retaining the Group A concept, Australia had applied its own interpretation of the rules in an ultimately unsuccessful attempt to avoid GTR domination. The VN and RS500 both gained 6 speed gearboxes, engine freedoms and weight reductions.

[Jesper OH]

What would a 1991 ATCC-spec. RS500 weigh? The Australian Sierras were never leightweights anyway - I've seen a 1095 kg figure for the 1987 Bathurst event, when the Eggenberger cars were close to the 1035 kg minimum. Later, figures like 1150 and 1180 kgs comes to mind, when the FIA demands were 1100 kgs.

Jesper

[anthony81901]

Don’t know what a RS500 weighed in at, but for 1991 the Australian Sierras were given a 50kg reduction so presumably they were carrying ballast to get to the minimum weight at this stage.

[racer69]

The weight reduction for 1991 was only a reduction from what the Sierra's weighted in 1990. CAMS gave the Sierra's a 50kg weight penalty for the 1990 ATCC, the removed it for 1991.

Only 300 VNs were built in total, Holden did a deal with CAMS mid-way through the year to let them getaway with not building the other 200. CAMS presumebly had no problems with it due to A)due to a new CAMS money making scheme the grids were thin for 1991 and they wanted them out there, and B) the cars had been designed and built with the 500 in mind, so no real advantage had been garnered. The AA article states that this was only a deal with CAMS, and the car wouldn't be eligible to be homologated with the FIA, but seeing as Group A wasn't a world formula by then, it didn't matter.

As for the gearboxes, i assume they were free given the Commodore's from August 1985 were using Getrag's

[zakspeed]

championship french mountain
jean christian duby vuillafans echevannes 1992

[zakspeed]

european championship mountain saint ursanne les rangiers 1991 and 1990
driver: nicolas buhrer
http://www.euromontagna.com/driver.p...&id_driver=379
préparateur : eggenberger

[PAUL S]

Originally Posted by zakspeed

championship french mountain
jean christian duby vuillafans echevannes 1992

that cars currently for sale

[Crazy Craig]

Hello Chaps,

A very interesting thread! I was lucky enough to buy Chris Hodgetts “Brooklyn” car earlier this year and must say it’s an absolute dream to drive.
I always loved the 1988-1990 RS500 Touring Cars and was glued to every race (I myself was racing a Cosworth Sapphire in Mod Prods at the time)
I’m racing in Classic Thunder and DMN and have had four 2nd places this year, Chris Hodgetts met me at Brands and took the car out, he came back to the pits in tears as
this car meant so much to him and his career.

I have kept the car totally original and that’s how she will stay

Craig

[chunterer]

Craig, top man and thanks for coming on and sharing your thoughts!
It is indeed a lovely car and so nice that it's going to stay original for ever!

I once had a surprise when I saw it lurking at the back of one of Brooklyn's Kidderminster dealership sheds years back amongst a load of road cars. They must've kept it for a long time before going on to whoever you bought it from? That was probably 2000/01 time.

[Andy Clegg]

I remember watching Chris Hodgetts at the last Donington round in 1988 at Schwantz up on two wheels many times. Great driver.

[PAUL S]

Hi Craig

great to get yet another owner/driver of a racer onto the thread.

Ian said you were a very happy chappy with your car when I picked up my own RS500 road car from him not long after you purchased yours

Are you any the wiser regarding a proposed dedicated classic series for the 500s ?

[PAUL S]

Anybody recognise this fella



yours on ebay for a fiver plus post (I am not the seller, just spotted it when trawling ebay for RS500 bits)


http://cgi.ebay.co.uk/SIERRA-COSWORT...item3a6178bfc6

Mike might even offer to sign it for you !

[Jesper OH]

Searching for RS500 and coming up with an RS - just been doing a likewise search for music videos and original artists on YouTube

Jesper

[VIVA GT]

Originally Posted by PAUL S

Anybody recognise this fella



yours on ebay for a fiver plus post (I am not the seller, just spotted it when trawling ebay for RS500 bits)


http://cgi.ebay.co.uk/SIERRA-COSWORT...item3a6178bfc6

Mike might even offer to sign it for you !

Of course, that is his Prodsaloon, not a Group A car...

[davyboy]

Originally Posted by Jesper OH

Searching for RS500 and coming up with an RS

Odd comment... Are you saying what I think you're saying here

[Jesper OH]

Originally Posted by davyboy

Odd comment... Are you saying what I think you're saying here

As I don't know what you think - I'm not trying to second-guess here - I can't comment on that. Please, can we go back to the subject.

Was there ever a connection betwin Mountune, Trakstar and Jan-Åke Söderqvist in Sweden? In the early '90 1 hour endurance race Stig Blomqvist codrove the Robb Gravett RS500.

Jesper

[KA]

Originally Posted by VIVA GT

Of course, that is his Prodsaloon, not a Group A car...

though it did come out to play with the Group A gang at the 1987 Silverstone GP meeting...
http://media.photobucket.com/image/M...960/img011.jpg