As you’d expect, the suspension has undergone a general stiffening, with ZF Sachs twin-tube dampers all around, higher spring rates fore-and-aft, and a stiffer (by 0.71 inch) rear anti-roll bar. Given the car’s speed potential, the SRT team decided it was best to be conservative with rear roll stiffness. However, for hard-core autocrossers, Mopar plans to offer a track kit with much higher spring rates and firmer dampers.
The brakes are formidable: 13.4-by-1.1-inch vented front rotors squeezed by twin-piston calipers and cooled by vents molded into the front fascia, 11.9-inch solid rear rotors, and standard anti-lock. Not only does this system provide fade-free braking, but the heavy-duty dimensions of the front rotors allowed the engineers to be aggressive with the so-called brake-lock differential. The brake-lock diff is an alternative to a conventional mechanical limited-slip differential and relies on the traction-control system. Operating on info from the ABS sensors, it limits wheelspin by squeezing the rotor of the wheel that has lost traction, which sends power to the opposite wheel. This is not a new strategy—Audi, BMW, and Mercedes use this technique—but the SRT4 system operates up to 85 mph, much higher than any other, according to Dodge. The system tends to chew the rotors pretty hard, but the SRT engineers figure their robust setup can handle it.
Braking power gets onto the pavement via 225/45R-19 tires (optional Goodyear Eagle F1s on our test car). Other elements of the chassis inventory include power rack-and-pinion steering, traction control, and stability control. The latter can’t be entirely shut down, although its threshold is high. But it does add to the challenge of achieving optimal drag-racing holeshots.
The brakes are formidable: 13.4-by-1.1-inch vented front rotors squeezed by twin-piston calipers and cooled by vents molded into the front fascia, 11.9-inch solid rear rotors, and standard anti-lock. Not only does this system provide fade-free braking, but the heavy-duty dimensions of the front rotors allowed the engineers to be aggressive with the so-called brake-lock differential. The brake-lock diff is an alternative to a conventional mechanical limited-slip differential and relies on the traction-control system. Operating on info from the ABS sensors, it limits wheelspin by squeezing the rotor of the wheel that has lost traction, which sends power to the opposite wheel. This is not a new strategy—Audi, BMW, and Mercedes use this technique—but the SRT4 system operates up to 85 mph, much higher than any other, according to Dodge. The system tends to chew the rotors pretty hard, but the SRT engineers figure their robust setup can handle it.
Braking power gets onto the pavement via 225/45R-19 tires (optional Goodyear Eagle F1s on our test car). Other elements of the chassis inventory include power rack-and-pinion steering, traction control, and stability control. The latter can’t be entirely shut down, although its threshold is high. But it does add to the challenge of achieving optimal drag-racing holeshots.