TB993tt

<img src="http://boards.rennlist.com/upload/wheelcrack2.jpg" alt=" - " />
Noticed a vibration on the rear passenger side doing 110mph on Saturday - the GT2 magnesium centre has a crack in it about 7 inches long - apparently this happens a lot with these wheels <img border="0" alt="[crying]" title="" src="graemlins/crying.gif" />

Greg Fishman

Consider yourself lucky. I have some BBS Racing Mag. Wheels and broke one about 3/4 of the way around. I check mine at least once a weekend for cracks.

Anir

Scary stuff. At one point, I was considering magnesium wheels, but was told to avoid them since I drive my car to the track.

ruffy

making mental list to strike off magnesium rims from this years christmas list...

JWKC

I dont know if you aware that was a recall for those speedline wheels by porsche AG? Most of the 993 GT2 owner with those speedline wheel had given another set of those magnesium.

Konstantin

ALL Mg wheels must be checked at lest after 4 years and after that every year. especially if you race them.

Konstantin

Greg Fishman

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Konstantin:
<strong>ALL Mg wheels must be checked at lest after 4 years and after that every year. especially if you race them.
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">4 years? You are playing with fire in my opinion if you don't check them every four run sessions. Mine that broke where way less than 4 years old.

Anir

Greg,

How much weight savings are achieved with magnesium wheels, say over an aluminum wheel such as a Fikse?

Greg Fishman

Anir,
Compared to the same size Kinesis 9x18 and 11x18, I would say it is a good 4-5 lbs. BBS are around 17-18lbs, vs the Kinesis at 22-23lbs. What do your Fikse's weigh?

Konstantin

four year STREET driving on a smooth German Autobahn. NOT four years racing.
If you race with them it is better to check them after every race and replace after one year. (or check them till you see that they are broken)
usually the do not get bad by the stress but with the time. they easily survive the 24 hours in le Mans but they do not survive 10 years and the street even if you rarely move the car.

Konstantin

Greg Fishman

OK Konstantin, that makes much more sense.

Anir

Greg,

According to <a href="http://www.wheelweights.net/" target="_blank">Wheel Weight Page</a>, the Fikse FM-10's weigh 20.8 lb in the 8x18 size and 20.9 lb in 18x9.5. I don't know how accurate this is.

I also have the following written down from somewhere (can't remember the source):

·Porsche Turbo I (previously Technology) - 19.95 / 23.36 lb

·18” MY’02 Carrera wheels 18” - 20.50 / 22.70 lbs.

·18” BBS LM - 22.20 / 23.25 lb

·18” BBS RSII - 25.30 / 25.74 lb

·18" Porsche Turbo Look I (solid spoke) - 25.57 / 29.32 lb

·18” Sport Design wheels - 26.45 / 28.88 lb

·18” (8 and 10) RS wheels – 26.45 / 29.21 lb

TB993tt

Re the wheel weights:
The GT2 magnesium 11X18 with S03 285/30 on weigh 23.4kg (51.6lbs)
This compared with 993tt 10X18 hollow spokes with S02 285/30 weighing 24.4kg (53.8lbs)

TB993tt

Just taken the rears off to put on new SO3s and closer inspection revealed another cracked mag centre, it was the matching wheel to the first one and went in exactly the same way. Looks like I have another "maintenance item" on the list; new wheel every 5000 miles .

ruffy