tonyc

My mechanic has offered me some good quality second hand, 17" Porsche Cup magnesuim wheels at a good price, to replace my Design 90's. Does anyone know anything about Porsche Magnesuim wheels? Actually,I thought all high performance wheels were magnesuim!

cheers
Tony
'90C2

Roland Kunz

Hello

Porsche had wheels with different magnesium content or different "Blends". I´m still searching in the net.

High percentage Magnesium is normaly only used in Race wheels. Most street rims have no magnesium content.

Grüsse

tonyc

Thanks Roland. Does that mean that magnesuim wheels are not suitable for road use? I would imagine that anything used for racing would be of a higher quality and more durable than that for road use, but maybe I'm missing something here.

J richard

I doubt you will find too many modern wheels with a very high magnesium content. Most of the current factory wheels and aftermarket replicas are aluminum alloy. Once upon a time racing wheels were constructed out of alloy which had a very high magnesium content, the term "mag" wheel stuck, and now applies to just about any aluminum wheel. Magnesium is light but is also hard to work as a metal, generally only cast peices are made,they are suseptable to corrosion and do not keep a finish as well as alum. Compare a 2.7 case with a 3.0. Very high content alloys are actually flamable. (magnesium is used in making fireworks and sparklers) If you need to weld one you must be careful not to set the metal on fire.Minilite and speedline use to make true "mags" I think porsche only used them on old 906 to 917 vintage cars. I'm not too familiar with a cup racing wheel, most the cup wheels I have seen are the same as street cars except for the modulars with the cast centers and forged rims. Maybe he's got something special?

Adrian

Guys,
The parts catalogue refers to all wheels available for Porsches as Alu Alloy. No magnesium wheels. I also have a few articles on Porsche wheels and these articles supports Rolands statements that Porsch eonly used Mag Wheels in racing applications.
However please keep in mind that the use of the term "Mag Wheels" is very widespread and often is used to refer to all "non Steel" wheels. To confirm if the wheels on offer are genuine they have to be checked for their part number. I do not have the part numbers for the racing wheels so I recommend a quick fax to the racing department of Porsche with the part numbers off the wheels. Contact numbers can be found at the Porsche sites. If the US Racing Department cannot help, fax the factory racing department. I hope you find somebody,
Ciao,
Adrian
911C4

JC in NY

I wonder if he's referring to the special wheels that were used on the 964 RS cars that are supposed to be lighter than the normal wheels made a forged magnesium. These are supposedly very rare and expensive so I would make sure that's what you're getting if that's the claim. He's probably just giving you regular cup wheels (aluminum) and doesn't really know the difference. If they are the real RS cup wheels then you have a real treasure there.

tonyc

Thanks for your comments everyone. I'm off to see them this weekend and will find out a little more about them. I'll keep you posted.

cheers
Tony
'90 C2

Roland Kunz

Hello

The first magesium wheels where made for the 1967 S but Porsche chosed the wider 6" Fuchs rim and the 5,5" Mahle where sold on the 914/6.

Now there are differnt magnesium rims around. The 964 RS cam standard with 7,5 and 9 x 17 rims. Also the later RS and GT street cars had magnesium rims. I think the content is under 5%.

For the Cup and Race cars Porsche had a even lighter Magnesium rim with a much higher Blend.

Magnesium has some low sides and can´t be given to "normal" drivers.

The magnesium rims will corrode fast and do react much harsher if you hit them. The rims are also made for a specific task giving up other things like long time reialibylity.

In fact mostly the rims get weak under raceing and trashed, but sometimes the garbidge gets sold by people who don´t care or don´t know better.

To avoid re using the rims f.e.: Porsche race dept. does press them or pinch out holes.

Also those rims have a high visible embosed MG sing, some show the complete blend ( AlMg )