Spacers on a 73?

[marksearls]

Can you run spacers on the rear of a stock 73 and if so, what is the maximum before needing longer studs for the wheels?

[trak ratt]

Not much room under stock 1/4s so why the spacers? Measure how much stud sticks out of the existing wheel w/steel lug nuts. That's the max spacer you can run without longer studs.

[marksearls]

Got it, thanks. Looks like 1/8" is about the max. I am thinking of going with SC flares but stick with my 7x15's.

[fryardds]

I'm not sure how SC flares compare to RS flares, but originally the '73 Carrera was delivered with longer studs on the rear hubs and 7 mm spacers for the 7" rear Fuchs.

[RSBob]

Have 7s on my Euro-height '73 with no spacers and had to roll the lips with 60 series. 55s fit much better.

Wouldn't recommend adding flares on an E or S due to a major hit in value, but it's your dance.

[marksearls]

I knew the RS came with 7's but never knew the factory used spacers, interesting.

I'm not sure how SC flares compare to RS flares, but originally the '73 Carrera was delivered with longer studs on the rear hubs and 7 mm spacers for the 7" rear Fuchs.

[Grady Clay]

I think the ’73 Carrera 2.7 RS used standard (904.341.671.00) wheel studs (same F&R) and no spacers. The rear 7x15 just added 1” of wheel to the outside compared to the 6x15.


Since high performance 15” tires are limited selection, a suitable solution with RS rear fenders (~same as SC) is to use 8x16 in the rear and 7x16 in front. This allows better tire choices.

With care, you can squeeze in some tires using 8x15 and 7x15. The difference is that the tire moves more relative to the rim so a bit more clearance is necessary.

The 7x15 with 215/60VR15 and 6x15 with 185/70VR15 are original on the 2.7 RS.

In general, in order to ‘fill-the-fender’ it is better to use a wider wheel rather than spacing out the wheel. The technical reason is you are increasing the cantilever of the tire & wheel outboard of the wheel bearing. Yes, this was done with the 930 Turbo but the 930 has dramatically more robust rear wheel (taper roller) bearings. Your ’73 rear wheel (4-point) bearings have a ‘service life’ and will need occasional (100K mi?) replacement. Probably not wise to shorten with more cantilever.

Best,
Grady

[fryardds]

Hi Grady,

My information about the longer studs and spacers came from Konradsheim's Carrera RS book. Certainly not infallible but usually very accurate.

[Bill Verburg]

Originally Posted by fryardds

Hi Grady,

My information about the longer studs and spacers came from Konradsheim's Carrera RS book. Certainly not infallible but usually very accurate.

and it is correct

[Bill Verburg]

Originally Posted by fryardds

I'm not sure how SC flares compare to RS flares, but originally the '73 Carrera was delivered with longer studs on the rear hubs and 7 mm spacers for the 7" rear Fuchs.

both the '73 Carrera and later SC/Carrera rear flares were designed around a 9" ET15-12 wheel which is what they wanted to use for racing, there is a ton of space in there and a stock 7ET23.3 will look lost

You couldn't/wouldn't/shouldn't use spacers on a stock '73 w/o the Carrera or SC flares, the stock 7ET23 are hard enough to fit

Once they started putting 8 ET10.6 on the Carreras as the stock wheel they went back to the shorter studs and did away w/ the spacers.

Just as a FYI
compared to a stock 2.7 7 ET23.3 rear wheel
an 8 ET10.6 will have it's outer face 24mm closer to the lip and the inner face will be 1.4mm closer to the chassis
a 9ET15 is the preferred wheel(for performance) and will have it's outer face 33.7mm closer to the lip and the inner face will be 17.1mm closer to the chassis

[Bill Verburg]

Last thing, the 911 ST which had the same narrow fenders as a standard '73 911 used 7ET49 wheels w/ 6.5mm spacers and longer studs, modern clones have reported using 7-16mm spacers w/ most clustered in the 10-16mm range depending on tires