At the Geneva Motor Show next month, Fisker will be showing off the ‘advanced aluminum space frame’ that underpins the Karma plug-in hybrid and gives the car new levels of rigidity and strength.
Fisker Automotive’s engineering team designed the Karma’s space frame around the car’s unique Q-DRIVE series-hybrid powertrain, filing for multiple patents in the process. Q-DRIVE® consists of a 2.0-liter turbocharged ECOTEC engine/generator set, a lithium-ion battery pack from A123 Systems, and a rear-mounted 403hp traction motor assembly.
Though it forms the foundation of a large sedan the Karma space frame’s rigidity is exceptional even when compared to today’s sports cars. By utilizing 5,000- and 6,000- series aluminum alloys and a unique extrusion-intensive architecture, the Fisker engineering team achieved the best balance between weight and size.
A super-structural tunnel running down the car’s centerline acts as the Karma’s backbone. It not only houses the battery pack but acts as a torque tube connecting front and rear sections. For optimal strength the Karma’s space frame is joined with 79 meters of precision CMT MIG welds and 1,058 self-piercing rivets. Each technique is used independently only where necessary to ensure top quality and durability.
The result is an industry-leading space frame that provides a solid foundation for the Karma. Few cars match its statistics: Static torsional rigidity – the amount the space frame resists twisting forces when entering a ramp at an angle, for example – measures more than 33,000 Newton-meters per degree (Nm/deg). Static bending rigidity – the amount the space frame resists flexing forces as the car enters a ramp straight on, for example – measures more than 23,000 N/mm. Dynamic stiffness – the space frame’s resistance to resonant vibrations like those felt when driving over a sharp bump or rough road surfaces — is also world class.
Thanks to intelligent engineering solutions the Karma’s space frame also provides the utmost in occupant safety and exceeds global crash protection standards.
Front impact protection starts with a patent-pending, multi-cell tempered aluminum crush box that displaces high-impact energy away from passengers. Its unique design allows it to be easily replaced, reducing repair costs that could lower insurance premiums. Dual Phase 600-Series steel reinforced components in the doors and B- pillars provide substantial side impact protection. And the lithium-ion battery’s location in the center of the car puts it farthest from impact areas.
Valmet Automotive will assemble the space frames at its state-of-the-art facility in Uusikaupunki, Finland.[wzslider height=”400″ lightbox=”true”]