Rigid Backbone The backbone of the new WRX is its stiff structure, which provides a rigid foundation for the suspension and enables precise sense of direction and handling. At the same time, this structure helps isolate the cabin from road inputs.
Increased use of high-tensile strength steel along with special stiffening elements at key locations help create an exceptionally strong architecture that’s 41 percent stiffer. Structural braces help bolster the body’s resistance to twisting and flexing through added torsional rigidity and bending stiffness.
In the front suspension, upgraded struts, stiffer bushings, a thicker anti-roll bar, and spring rates raised by 39 percent are among the changes made to improve handling. There are similar changes in the rear multilink suspension, plus an increase in spring rate. The specially tuned suspension helps give the driver greater confidence during performance maneuvers. It corners at an estimated 0.91 g, with reduced body roll equivalent to that of a BRZ.
With the car’s new Electric Power Assisted Steering system (which includes increased bushing stiffness and quicker 14.5:1 steering ratio for better road feel) and Dunlop SP Sport Maxx RT tires, the stiffer chassis yields quick, precise steering response that’s 67 percent faster – as quick as 100 milliseconds.
Gripping Experience – Brakes and Stability Control The brakes feature 25-percent larger and thicker front 12.4-inch discs and a larger master cylinder to help keep a secure leash on the vehicle’s power and acceleration.
New Subaru torque vectoring is a brake-based yaw system that strokes the brakes of the inside front wheel during cornering to dampen understeer. That helps rotate the car into corners.
The multi-mode Vehicle Dynamics Control (VDC) stability-control system still has three modes, including Normal, Off, and Traction. Traction is a track-like mode that defeats stability and traction control but retains the torque-vectoring function to better follow the driver’s intended path.
STI Parts for the 2015 WRX
A Lot More
There’s more, of course, such as unique styling and a roomier, more refined interior that features a Harman Kardon®1 premium audio system.
by David Higgins
1 Harman Kardon is a registered trademark of HARMAN International Industries, Inc.