Forging Ahead: Magnesium Road Wheels

From The Virtual Driver
By Christopher A. Sawyer

Just a few years ago, Bill Koenig was Carbon Revolution’s Director of Sales and Marketing. In that position, he brought the carbon fiber road wheel maker to such prominence it is now the factory wheel for the Mustang GT 350. Now the self-described “lightweight freak” and long-time Porsche owner has a new career as Executive Vice President of California-based MKW Alloy Wheels, where he is on another lightweight wheel quest. Only this time, he’s trading fiber for an exotic (for road cars) alloy.

Koenig was able to convince “a Japanese company that builds forged magnesium wheels for multiple Formula 1 teams” to build a forged magnesium design “optimized for both street and track.” That’s not a bad selling point for a set of wheels that will have real world benefits as well as snob appeal.

Porsche’s 911 is the target vehicle for the first production run as these owners are not only well-heeled, they also are rabid about using them at track days. Wheels for the 911 GT3, for example, come in a 19-in. diameter and widths of nine inches (front) and 12 in. (rear). However, unlike the $15,000 Carbon Revolution wheels, the forged magnesium rims — which sit between the factory alloys and composite wheels in terms of stiffness and heat dissipation — cost a relatively inexpensive $8,800. That’s just $700 more, for example, than the carbon composite brake package on a BMW M4.

“The Japanese have metallurgists on staff working with suppliers to ensure the magnesium alloys are to spec.,” says Koenig, and the design works for “multiple applications without having to forge multiple blanks.” A good thing since tooling for each wheel design costs about $100,000. “We developed profiles that work on multiple vehicles,” he says, “and the rotational mass is about three times less than a stock alloy wheel.” To put it another way, that’s just short of the reduction Carbon Revolution is quoting for its much more expensive wheels.

MKW’s forged magnesium wheels are part of its RSR (“Road, Street, Race”) line. Road rims are exemplified by cast-aluminum wheels. Street wheels use flow-form casting that spins the heated form in order to get the aluminum to flow and bind together. This creates a wheel stronger than a cast design, but with a thinner cross-section. The Race units are the forged magnesium wheels. Eyeing the success of Carbon Revolution’s design with Ford, Koenig is quick to point out: “We are open to new projects and vehicles other than Porsche.” He and the folks at MKW Alloy Wheels may not have long to wait before an ambitious automaker comes knocking.

Author Chris Sawyer