Hydroformed Aluminum Frame Rails Help GM Reduce Stingray Weight

5th June 2013

This summer, Vari-Form will begin production of all-aluminum hydroformed frame rails for the new-generation 2014 Corvette Stingray. This advanced technology yields greater design strength, torsional stiffness and vehicle durability. Fuel economy is another important deliverable, resulting from lower weight and reduced complexity made possible by patented Vari-Form Pressure-Sequence Hydroforming.

Hydroforming is gaining traction in the automotive market as car makers seek to make weight savings. The process uses a high pressure hydraulic fluid to press material into a die. It is often used in the high end sports car market where lightweight materials such as aluminum are more common but is increasingly being used in high volume vehicle applications.


Backbone of the lightweight aluminum 2014 Corvette Stingray frame is a set of hydroformed aluminum tube center sections from Vari-Form (blue highlight), bridging the gap between two pairs of connecting nodes and front/rear crush-zones.


The integration of Vari-Form hydroformed frame rails in the new 2014 Corvette Stingray brings forward expertise successfully applied to the current model 2013 Corvette. The Vari-Form manufacturing facility in Strathroy, Ontario, Canada received the General Motors Supplier Quality Excellence Award in 2012 for consistent operational excellence related to the production of this component.

For 2014, the Corvette Stingray incorporates substantial structural changes, resulting in a 99-pound (45 kg) reduction in weight and a 57-percent increase in stiffness compared to the steel structure of the previous model.

Vari-Form Pressure-Sequence Hydroforming technology is a major factor in achieving these advances, which are critical to balancing the need for exceptional performance while addressing ever-stricter crash regulations. It was important for Vari-Form to develop an improved, dimensionally stable frame, starting with the frame rails. The backbone of the body structure is a new frame concept that features left and right hydroformed aluminum tube center sections, bridging the gap between two pairs of connecting nodes and front/rear crush zones. Hydroformed frame rails are optimized for light weight and superior strength, helping deliver classical Corvette handling and improved mileage for the driver.

“Our company is pleased to be part of the biggest model-over-model change to this American icon in decades,” said Vari-Form President Stephen Dow . “We tailor the hydroformed aluminum components with the gauge, form and strength needed to help GM realize significant weight advantages, optimal 50/50 front/rear weight balance, world-class power-to-weight ratio, and increased fuel efficiency. By pioneering new technologies and processes, Vari-Form contributes to the achievement of these important goals.”