brad@tirerack.com

A good pressure cast and heat treated wheel like the OZ will be very close in strength to a forged wheel. Today's pressure casting techniques assure weight and durability very close to forged wheels - at half the price. Of the companies doing it, OZ is among the best. The Allegerita and Ultraleggera (and more recently Leggera) have been staple race wheels for years with next to no track related issues. It's the number one brand I sell for Porsche. Bends and breaks happen to any wheel, cast or forged. It's part of alloy fatigue. The track is a tough place. If your wheels are inspected at regular intervals like they should be, you should have no issues with the OZ product holding up. Testimonials here should prove that.

Call me if you have any questions!

Bill Lehman

The OZ Allegerita has almost become the "standard" wheel for tracked Caymans. I've been running them for years and I am an aggressive curb jumper. No issues. Planning on a set of Leggeras for my incoming GT4.

ExMB

Just because one is running in advanced DE groups does not define wheel failure as a condition of failure. And not wanting to ID these wheel manufacturer's because of a claim doesn't invalid the fact that you brought "cast" wheel failures up in the first place.

Please reread my questions again.

AudiOn19s

I've got many friends who have run the OZ wheels without issue and put a serious beating on them. None of them have owned the wheels more than 3 years though. The question in the back of my mind is how long will they go before they fatigue and start to crack???

None the less I just ordered some to use with my Nitto's. My slicks will remain mounted on my CCW's.

No wheel is going to last forever. I got about 7 years out of my CCW rears before they started cracking BADLY. only one is those seasons was on slicks. Check whatever you have and check it often.

Dwane

Hairline cracks in centers
Under 30x20minutes for 2 guys
1 on street tires
1 on 01's
1 on 888's(brand new wheels, fifth lap, second session) last guy

ExMB

2 guys, but 3 different setups. Since you won't ID the wheel manufacturer(s), or the cars they were mounted on and by whom, one can only assume cheap knock offs from ebay. And you equate those to a manufacturer with a very good reputation in the community.

Frank 993 C4S

This discussion reminds me of last year's Conti Race at Sebring. Terry Borcheller:

Dwane

You must be good with math 1+1+1=2

...and no I won't bad mouth any of the manufacturers since it ain't my scratch in the game.

911,993 and a 944 cup car
Mounted by a race shop

The 944's may be cheap knockoffs, not sure what is going on with that....

Dwane

The 3 guys are also Rennlist members....

333pg333

No takers for Fikse's? Not great communication but a good wheel imho.

Cory M

As far as the properties of cast versus forged parts go, I have worked on both. I have been able to make direct comparisons of parts with same geometry and material, with the only differences being cast, precision forged, and near-net forged and machined. This was on stainless steel parts not aluminum. The tolerances on the cast parts were significantly looser than the forged and machined parts, and even still there were more discrepant dimensions. It’s just a harder process to control and there is a lot more part-to-part variability. The majority of OEM wheels are cast though so obviously wheels can be cast within an acceptable tolerance range. Strength was mentioned earlier, ultimate strength only tells part of the story and it was about 12-15% less for the cast parts I was working on (not aluminum). The grain structure of forged parts is superior to cast and they are much less likely to have inclusions, porosity, or other indications. Stress concentrations at these indications (even small ones) are usually where fatigue cracks initiate. The grain flow of a properly forged part is better than cast and contributes to increased fatigue resistance. Forging produces parts that are stronger and more fatigue resistant, with less variability and tighter tolerances. It also costs more money. You aren’t going to see top level motorsport teams switch to cast wheels from forged and I wouldn’t race on a cast wheel from an unproven brand.

So forged is better than cast, but you can't discount cast wheels completely. It appears that OZ has made a durable and reasonably priced wheel with the Alleggerita. They are in wide use on Caymans and 911’s at the track (and street) and appear to be holding up well. There are a lot of them out there so if they were failing regularly I think the word would be out by now. They might not be the ultimate lightest and strongest wheels you can buy, but it’s really nice to have some decent race wheel options that retail for under $2k per set.

997rs4.0

Are there any manufacturing dates on OZ wheels?

JPS

Kind of where I netted out. Forged better but $. I tried to find used but couldn't get the offsets + price + availability to work out. Ordered new OZ.

Dwane

Congrats on the new wheels JPS.
Ordered another set(Discount Tire EBay sale) of Nitto's for the CCW's.
If you ever make it up for a DE at Tremblant, let me know.

Best,
Dwane

brad@tirerack.com

Did you order them from us? If so, PM me the order number. Thanks.