1974 Carrera Coupe - RHD, UK car

[Bootsy]

I find gearbox pics quite stimulating. My last 915 rebuild cost just under £3k, obviously about par for the course.

[Ferry Man]

I think you have cornered the market in a new line of gearbox porn

I find gearbox pics quite stimulating.

You guys.
One last gearbox pic to keep you amused for a week or so and then upon my return I'll post up some pics of the shell restored to rust-free.

[jamie]

Do it right, do it once. Lovely stuff Paul.

[Ferry Man]

OK, I'm back from my Mediterranean poolside confinement, let's get the thread moving along again.
So, now the talk turns to steering wheels.

This is a nice '74 Carrera with the correct wheel. But you need a trained eye to tell at a glance.

[Ferry Man]

The 1974 Carreras were fitted with a new 'sports' steering wheel.
It was a three spoke design and was also used on the Porsche race cars of that era.
However, it only lasted through the '74-'76 model years before being revised to the later 'SC' version.
The ‘SC’ version would be incorrect for my car.
Both the early Carrera and the later SC wheels were the same 380mm diameter (420mm for a 'standard' wheel of that era) but there are differences.
The SC style remained in production, unchanged, for many years. Certainly up until at least 1984.

But the correct early Carrera wheel is nowadays very rare.
It does have its unique identifiers and whilst it’s not so very dissimilar to the later wheels, they are certainly less numerous and if you have a '74/75 Carrera then you'll be wanting one.

So, how to spot one?

[Ferry Man]

This wheel is incorrect....


And yet this one is correct....


Can you notice the difference?

Apologies for using images found on the web (I forget the source), they do illustrate the differences well but if you’re the author and want credit just let me know and you’ll get the accolades you rightly deserve.

[Ferry Man]

So, how to spot one?

The rim is thicker than the later version. But only by about 10%.

Also the grips on the reverse are different.

The steel plate in the centre of the wheel is a much heavier grade than the pressed steel of the subsequent model.
Maybe the rim steel core is also thicker on the early wheel?
What it means is the later SC wheel is markedly lighter.

The collapsible safety 'crush' tube should have diamond perforations whereas the newer version has simpler round holes.

[Ferry Man]

However there is another important difference and it's the fact that the '74-'76 wheels are hub-centric (centred on the wheel).
The later wheels are offset. The hub is dropped down from centre.

Yep, it seems odd to offset the hub from the middle but Porsche did that for two reasons.
In moving the hub down it served to raise the rim and thereby afford a less restricted view of the dials.
It also helped to facilitate a modest bit of extra leg-room under the wheel.

Now, it isn't easy to spot at a glance which version you're looking at.
The rim thickness is pretty much imperceptible, the hub offset is difficult to see but possible once you know.

Here's a useful side-by-side comparison I drew up.
You can see the wheel on the left is hub centric.
On the later SC wheel (pictured on the right) the hub is lower. It's not much, probably only 10mm or 15mm.

[squirdan]

Surely all that matters is which one provides the superior contact points for driving the car? !

[brembo]

However there is another important difference and it's the fact that the '74-'76 wheels are hub-centric (centred on the wheel).
The later wheels are offset. The hub is dropped down from centre.

Yep, it seems odd to offset the hub from the middle but Porsche did that for two reasons.
In moving the hub down it served to raise the rim and thereby afford a less restricted view of the dials.
It also helped to facilitate a modest bit of extra leg-room under the wheel.

Now, it isn't easy to spot at a glance which version you're looking at.
The rim thickness is pretty much imperceptible, the hub offset is difficult to see but possible once you know.

Here's a useful side-by-side comparison I drew up.
You can see the wheel on the left is hub centric.
On the later SC wheel (pictured on the right) the hub is lower. It's not much, probably only 10mm or 15mm.

More info here Paul-
http://forums.pelicanparts.com/porsche- ... wheel.html

[pht9]

It's easy to spot from the lower spoke being longer

I am about to fit one of these onto my SCR, as the current Prototipo feels a bit flimsy (it flexes) compared with the feel, grip and rigidity of the Carrera wheel. It was expertly renovated by Jonathan Parr
I am having a 70mm spacer made for it, to bring it closer to me. I have my seat quite a way back, and its a bit of a reach without spacer. It's not an easy task, so the spacer will sit between the original crash structure bub and the steering wheel frame. Will update my build thread when it's installed (sorry to hijack your thread Paul )

[Ferry Man]

More info here Paul-

Thanks Dougie, I hadn't seen that Pelican thread. Fortunately it seems to echo what I've said. So, it must be true.

[Ferry Man]

I am about to fit one of these onto my SCR, as the current Prototipo feels a bit flimsy (it flexes) compared with the feel, grip and rigidity of the Carrera wheel.

I does feel like a nice wheel. I don't doubt the later wheels help your view of the dials but they don't feel as good in the hand.

I am having a 70mm spacer made for it, to bring it closer to me. It will sit between the original crash structure bub and the steering wheel frame.

That's quite some spacer. 70mm? Wow. Good idea on the placement though. I'm guessing the plastic trim to the back will no longer be able to be used?

[Ferry Man]

Fortunately the original wheel came with my car.
It was in good shape but the leather was hardened with age and very polished. Also some of the stitching had come undone.
The wheel centre and plastic trims to the reverse were in good order they just needed careful cleaning.

[Ferry Man]

some of the stitching had come undone.