Originally Posted by Red Bread
I have powdercoated wheels on my Z3 M Coupe and they've been tracked extensively. The shop that did mine specializes in motorcycles and knows quite a lot about heat cycles and temps for doing this properly. That answer by BBS is baloney though, grab a heat gun next time you're at a track and every part of the wheel will be way beyond 190 and even after cool down laps, it's not uncommon to see hub temps over 350.
I've been very happy with powder for my wheels, but would strongly suggest finding a shop that knows their stuff, not just picking the cheapest.
Wheels are giant heatsink that are exposed to ambient air temperature. If your hub is 350 degrees and heat transfers to the wheel, it radiates and cools down your hubs. In an oven the ambient temperature can be up to 400 degrees with no chance of cooling down. That is already 50 degrees more than your hub temps and on the whole wheel.
It is amazing to me how quickly people discount engineers or other professionals that actually make the stuff.
Powdercoating is probably fine if you check at how it is done. I have supplied some basic information from BBS which can help the original poster make an informed decision and he can ask the powder coater what temps and for how long he cooks the wheels.
The reason powder coating is cheaper is because most places paint a bunch of items and put them in a giant oven at a temperature that works for everything.... including steel, cast iron, etc.
So a temperature that might be good for steel might not be so good for cast aluminum. When someone like BBS powdercoats their wheels, I am certain they put only wheels in an oven to temps that are appropriate.
To the Original Poster, good luck.