Hi. Sorry if this has been asked before; I couldn't find it in a search but that's probably me.
I'm in Z06 bent wheel club. I'm looking at options. I see a lot of nice wheels that are relatively affordable that are flow formed or flow forged. The ads and websites say they are stronger than the OEM wheels. But aren't the stock wheels flow formed? How are the aftermarket flow formed wheels any stronger?
For those of you that have the flow formed wheels, have you experienced bending or cracking?
Any input from owners and vendors is greatly appreciated.

Thanks
Joe

 

I bent the original wheels and then replaced them with rotary forged wheels. I bent three of them going over a railroad track that had not been properly maintained (no, I was not going over the speed limit). Then Jerry from CW4L.com set me up with some HRE mono block wheels that I have never regretted investing in, work great and have taken on (without bending) impacts as hard, or harder, than those that bent my previous wheels.

 

I doubt the stock ones are flow formed. I think just cast and machined on needed surfaces but not sure.
we sub out some wheel work where I work that is a similar process on 4140 (not for cars)
Kind of like running a lathe but instead of using a cutting insert it's more like a roller that slowly works the material into shape
same principals as thread forming vs thread cutting

 

ZR1 wheels are flow-formed. GS/Z06 wheels are not, they are cast. Flowformed is better than cast but not as sturdy as fully forged. If you don't track the car you may do fine with flow formed wheels and you can buy 2-3 sets for what a set of forged will cost. If you want to never have to mess with it again then just pony up for forged wheels. Check out the for sale section on here too. Every now and then you'll see some forgeline or signature wheels for sale at a discount. Signature (Competition Carbon) and CW4L are both great forum vendors who sell forged setups.

 

There is a WHOLE lot of misinformation, in that the suppliers try to call spun wheels "flow forged". As an engineer I can tell you that is not a "real" thing. Forged is when a billet of aluminum is hammered into shape using many tons of pressure, thereby aligning the grain structure into a stronger form. This is the strongest wheel you can buy...and it is the only forged wheel.

If they try to tell you they are flow forged, spin forged, or any other forged...it is a marketing scheme. In a "flow forged", or more correctly named "spun" wheel, the aluminum is heated and then spun rapidly while a tool forms it into shape. There is no pressure envolved as in true forging.

So...the OEM wheels are spun, or flow forged as they like to say. They are weak. If you buy an aftermarket set that claims to be flow forged, then they are essentially made the same as the OEM wheel. There is a chance their design is marginally stronger than OEM...but only marginally at best. They could also be weaker. Personally, the OEM wheels are so weak that I want nothing to do with "similarly" formed wheels.

If you want a wheel that will last without issue, you need monoblock forged. You will not find them new for less than $4k, and the sky is the limit on the high side. If you find a set for less, then chances are they are playing you with the old "flow forged" trick.

 

So Track, are you saying that a set of forged wheels will run 4K or are you saying 4K per wheel. I'm guessing the answer is yes and yes...lol

 

Thanks for the replies. They confirm what I was thinking.

Joe

 

Fully forged wheels are not perfect either. They are definitely the strongest option but don’t think because you spend $ means they’re infallible. We have very low profile tires with wide barrels, and a reinforced sidewall to make the tire a runflat. All of these contribute to the stresses our wheels see.

Here’s a fully forged, American made wheel that I had on another car of mine. The barrel of the wheel wasn’t bent. I found the crack when polishing the wheel.

 

I am saying I have not seen real forged wheels advertised anywhere for less than $4k for a set. There may be, I just have not seen them.. The options I have seen for less are the spun wheels. I paid $5400 for a set of 4 Forgelines. I also never said forged wheels cannot be broken...simply that they are the strongest alloy wheels you can buy. And Fat, it looks like your failure is a manufacturing flaw...which can happen. If it happened within a reasonable amount of time (like a couple years), most reputable manufacturers will make good on it. Since it loosk like a modular wheel, there is always a chance they were mis-assembled at some point, which could still be manufacturing if you have never split them yourself.

 

No, I didn’t split them. They’re older, and this manufacturer had this happen more than once. But I’m getting way off topic.

You can’t go wrong with Forgeline.

 

I have recently gone to these Forgestars. Thus far, I am very happy with them and the last Street Car Takeover I went to a few weekends back there were a lot of cars with these on them. They are very popular right now.

 

I’ve done several weekends with both NASA & SCCA. Forgestar are the most popular wheels at the track in these events by a wide margin. BMW guys run a lot of Apex wheels, also a flow formed like Forgestar. Higher end cars run forged wheels, but not always.
When I’ve run HPDE with Chin most run forged wheels - wealthier crowd.