DDK - Die Deutschen Klassiker

Ferry Man wrote:...there are Carreras even within the 1974 model year that are more sought after than others.
And those cars are elevated in rank because they share even more in common with their exalted brother.
The fact is the very early cars in the production series were built with remaining RS shells.
They have RS style tunnel reinforcements.

The very early build ’74 Carreras were also fitted with ‘RS’ flares.

The rear wings on the base model 911 and on the ‘S’ were the normal narrow body style.
However, on both USA and Euro Carrera cars the arches were wider, just like the RS.

So, here’s a little lesson on RS arches.

When the RS of 1973 was developed Porsche wished to run with wider rear wheels and that necessitated flaring the arch.
Rather than re-tooling the complete rear quarter (believing there wouldn’t be much demand for the new car) they simply welded a flare on to existing narrow body wings.

The later (we’ll call them ‘SC’ style) wings would be the same flare width as the RS but they had a slightly different ‘lip’.
The SC arches have an even margin all around the radius (approx 20mm) whereas the RS arches have a deeper lip profile at the top of the arch (extending to approx 28mm tall) and the ‘return’ into the main body of the wing is perhaps a little softer in the crease.

There are a few folk on DDK that can determine which arch you have with just a glance.
It takes a trained eye but once you’ve mastered it you can belittle owners with a sneer and a few curt words.

However, it’s very difficult to be certain as to how specific cars were configured.
So few cars remain with their original panels that a precise determination of when the changes occurred is difficult.
Also your best opportunity to find a rust free car with original wings still in place would be to discover a survivor from warmer climes or even a desert state (like the West Coast, USA) and yet the Euro Carrera wasn’t exported to that region.
So you find yourself tracking down US spec Carreras with RS arches and trying to determine the build date and matching that to the Euro spec production.
There are many complexities. So, I will say – based upon the research of wiser men than me – it is believed the change happened after approx the first 240 cars were built.

I personally think that the change probably happened a little earlier, maybe somewhere around chassis numbers 0200-0220.
But other learned folk believe the switch to be rather later and somewhere in the sequence 0230-0240.
So a consensus would possibly agree it lies somewhere between car No.200 and car No.240.

I am pretty confident in saying a pre-0200 car should have RS arches and anything post 0240 will definitely be the later SC style.
I don’t believe this applies to Targas (Porsche not having ever made any such thing as an RS Targa rear quarter for the ’73 model year cars).

The factory changed to the '74 model year (IB) cars after the August holiday break.
In that first month I do not know of a September built car that didn't have RS arches fitted originally.
I believe that mid-October is when the RS arches ran out.
Any original survivor cars I’ve seen that were November 1973 built, appear to be configured in the SC version.

Therefore my modest research of the build dates (in conjunction with that of the chassis numbers) leads me to believe the stock of RS arches was exhausted in the middle of October. That is informed speculation but it’s getting impossible to define the crossover point any more accurately than that.

I think the RS tunnel reinforcements also ended around this time but I’d love to hear from anyone with a car configured as such but built later than mid-Oct ’73.
It’s quite possible the arches and tunnel reinforcements ran out at different times but you’d imagine the factory would have ordered similar numbers of both parts? I don’t know.

So, whilst some of this is conjecture, I'd say - as best you can 40 years after the event - that the changeover can be pinned down to within a couple of weeks production and amongst a spread of less than 50 or so cars.
In light of this (and along with the remaining evidence of my cars tunnel reinforcements) I am therefore quietly confident that my car should have RS style arches and I will rebuild my car accordingly.

Ferry Man wrote:The SC arches have an even margin all around the radius (approx 20mm) whereas the RS arches have a deeper lip profile at the top of the arch (extending to approx 28mm tall) and the ‘return’ into the main body of the wing is perhaps a little softer in the crease.

And this is a great comparison shot that shows the difference (apologies for pinching the picture of the web, if you're the author let me know and I'll credit you).

The top pic shows the later SC arch. The lower photo pictures an RS.

And this shot shows the subtle curves of a genuine RS arch. It's a lovely shape.

Another shot of genuine RS arches. The lip deepens at the top of the wheel opening and doesn't have such a 'sharp' edge to it where it returns to the body of the car.

In the Porsche brochure for the new 1974 model year cars, the vehicles are illustrated with RS style arches.
That makes sense because those cars would have been built in the second half of 1973 (as was my car).
This is the Carrera pictured on the cover of the ’74 UK brochure.

This is an early build, '74 model year Carrera (in this instance a USA Carrera).
You can see it's original paint and panels.
The build date is Sept 1973 (like my car), the arches are RS style.

Another US Carrera. This one is a September build too, chassis number 0063.
It's pictured without the sill covers on yet, but it is a '74 model Carrera.
And it came from the factory with 'RS' arches.

Ferry Man wrote:This is an early build, '74 model year Carrera.

Never seen a '74 Carrera in Light Yellow before... Stunning. Love the contrasting green graphics & wheels.

I can add to this Paul, the US Carrera I had was an early car #245, it had RS flares (and an RS duck !), plus the Acid Blue car we restored #740, also had RS flares, the butt welds looked factory, pretty confident they were original

12 weeks to do this shell? superb imho.
Is that 12 man weeks or several on the shell during that 12?

To simply start and keep going until done is even more commendable?

911hillclimber wrote:12 weeks to do this shell? superb imho.
Is that 12 man weeks or several on the shell during that 12?
To simply start and keep going until done is even more commendable

I was billed 570 hours. Which was less than Chestertons indicated at the outset.
It went together quicker than they expected (thanks largely to the use of so many new panels).
It wasn't solely one guy but the bulk of the work was undertaken by Roy. Thanks Roy.

pht9 wrote:I can add to this Paul, the US Carrera I had was an early car #245, it had RS flares (and an RS duck !), plus the Acid Blue car we restored #740, also had RS flares, the butt welds looked factory, pretty confident they were original

Thanks Phil, that's fascinating insight. I can believe #245 would have RS arches.
Surprising to discover #740 having them too, but it's good to hear of later cars that also had the welded on arches.