Wheel opinions please

[RKturbo]

Thinking about getting these http://www.hstuning.com/product_info.php?products_id=4403 They are VMR V810 19x8.5 or 9.5 and would get them powdercoated flat black. I like they are pretty cheap, light weight and I do not have to use bore/ring adapter or a spacer for the 8.50 inch but I guess it looks like I would need to run a 5mm spacer if I went with the 9.50?

Wanted to get opinion of my fellow RS6 owners. BTW I will have a like new set of 19" TSW Silverline in black soon if anybody is interested.

[hahnmgh63]

I do get nervous about Powder coating wheels, especially cast wheels as a little too much heat can weaken a cast wheel at a lower temp than it would a Forged wheel. Most common allows for Aluminum wheel are 356 T6 and 6061 T6. The Forged wheels are treated at a little higher temp so are less likely affected. Manufacturers that Powder Coat use very careful procedures with lower heat and time but you never know about the places you find in the phone book so be careful.

[JayB]

I do get nervous about Powder coating wheels, especially cast wheels as a little too much heat can weaken a cast wheel at a lower temp than it would a Forged wheel. Most common allows for Aluminum wheel are 356 T6 and 6061 T6. The Forged wheels are treated at a little higher temp so are less likely affected. Manufacturers that Powder Coat use very careful procedures with lower heat and time but you never know about the places you find in the phone book so be careful.

Really?

At what temp is the powder usually baked?
I thought it was only a couple hundred degrees.... like baking a cake

[bmlee007]

Maybe a better option is to plastidip the wheels. Then you could change/refresh the look any time you want for significantly less $$$$.

[vw-nut]

I have to reply on this one...
Most aftermarket wheel in cast are cast from 5056-5156 aluminum, every ones got there own add mixes like boron, magnesium, nickle, silicone,tin, zinc, manganese ect but the qty are less than 2% by weight so most wheels fall into the 5000 series content family... the vast majority of wheels are heat treated after the first (rough) machining process. Heat treating goes like this.... wheels are racked up 100 at at a time or so... brought up to 830 degrees plus or minus 15 degrees very tight temp tolerances, they are held there at temp for 30-35 minutes core wheel temp, immediately the wheels and rack are fully submerged in ambient temp water and held til core temp is reduced to ambient. Then wheels are then put back in the oven and normalized at 475 for 3.5-4 hours depending on wheel size and overall material weight per wheel. Then post heat treating machining to final tolerance takes place. Now there are a handful of factory and aftermarket wheels that have no heat treating done at all, mille miglia, most mid 90's 3 series BMW wheels made by fondmetal, most if not all Ronals and newer Volkswagen wheels in sub 19" sizes. These wheels are inherently soft, very very soft...
The process of heat treating for some MFG is avoided all together due to casting techniques used, like high pressure casting where the metal is forced into the mold via hydraulics produces a wheel with near forged metallurgy when viewed cross section under microscope, no heat treating needed. A newer technique is a process called flow forming a cast or billet face with generous wall thickness near face is produced with no back barrel to speak of then the flow forming process splits the extra metal off the face and flows out a barrel (see youtube "flow forming wheel") this process creates a forged like grain structure in the back barrel and assuming a high quality process was used to produce the blank the result is a near forged item.

Onto powdercoating:
90% of all wheels produced with a finish are powder-coated top coat at least, some Mfg are using a powder suspended wet base sprayed in a conventional manner however the wheel is then topcoated with powder coat clear for UV and elemental protection while simultaneously curing base coat.
Powder-coating takes place well below the threshold of annealing, powder is baked at 300-to a max of 375 for 20-40 minutes Mfg dependent. Cast, flow formed, rotary and drop forged wheels will 1st stage annel at bottom value 570 f. core temp, so how a yellow page powdercoater could ruin a wheel is a bit of a mystery.....second stage or soft annealing occurs at 680 where any noticeable damage would occur.

Drop and rotary Forged wheels don't actually get heat treated at all they are normalized at 575-600 degrees to relive stress and work hardening from the forging process before they go for tolerance machining and final finish. Heat treating a forged wheel would negate the inherent strength of forging the wheel to begin with.

With 20 years in the wheel Industry as a production engineer and process controller (UBE north america) now as a wheel re-mfg, I think I am well qualified to answer this post
Proceed with your project and have your wheels powder-coated any color you wish, just make sure they don't apply powder to the mounting pad or lug seats.
Please stay out of the plasti dip Isle at home depot.... Ever try taking ALL the plasti dip off a wheel....make for a great weekend nightmare...its a temporary solution with near permanent overspray....

[vw-nut]

BTW
VMR makes a nice wheel, low pressure cast, good metallurgy, tight tolerances, decent finish quality. They don't normalize at as high a temp as maybe they should so there is a bit of "stress" still in the wheels and any bends from potholes will usually result in a crack, but all in all good stuff for the coin invested.

[DHall1]

I second the VMR quality

And they have started adding flow formed wheels


BTW
VMR makes a nice wheel, low pressure cast, good metallurgy, tight tolerances, decent finish quality. They don't normalize at as high a temp as maybe they should so there is a bit of "stress" still in the wheels and any bends from potholes will usually result in a crack, but all in all good stuff for the coin invested.