SRT® Hallmarks: The stout A580 automatic transmission lays down the power.
When it comes to high-power and high-torque engines, a capable transmission is a must. While there were several transmission options available, the SRT® powertrain team chose the tried, tested, ultra-dependable and more-than-capable A580 five-speed automatic.
The A580 features adaptive electronic control, or Auto Stick driver-interactive manual control, and an electronically modulated torque converter clutch. The A580 is all about performance, achieving lightning-quick shifts in the neighborhood of 180-200 milliseconds.
"There are not many transmissions out there that deliver the amount of performance that this transmission delivers," said Marty Jagoda, Vehicle Integration Responsible, Chrysler 300 SRT/Charger SRT. "It is a planetary transmission, and it really does its job in our products."
Paddle shifters on the steering wheel of an SRT vehicle allow the driver to shift the automatic transmission without taking his/her hands off the wheel. The auto stick on the console offers the same operation as the paddle shifter.
"A nice feature with our paddle shifters is that when you enter paddle mode, by either tapping one of the paddles or tapping the auto stick (in either Sport or the new for 2013 Track mode), it will actually hold the gear rather than auto upshifting," explained Jagoda. "You can take and run the vehicle right up to redline and it will bounce off the rev limiter just like a manual transmission vehicle, putting the driver in control."
If a driver is shifting up through the gears aggressively in track mode, the transmission will hold the gear a little bit longer. Many vehicles will instantly shift up a gear as soon as the throttle is lifted, but that is not the case in SRT vehicles equipped with the A580. For instance, going through the apex of a corner, or any sort of carousel in track mode, a driver may want to hold a gear longer, delivering the torque desired and making the car feel comfortable. The transmission knows not to upshift in that instance in track mode and will allow the driver to hold that radius and shift coming out of the corner based on the amount of steering input and throttle applied. In turn, that will deliver a more optimal gear ratio for spirited driving.
Part of the improved shift schedule is the ability of the A580 to move to a higher rpm before shifting, in many ways mimicking a manual transmission. This puts the control back in the driver's hands, allowing for multiple feels, especially when driving in Auto, Sport or Track mode.
"The A580 is going to go up to the rev limiter and uses what we call a soft-rev limiter," said Jagoda. "A hard rev limiter would be where you are bouncing really hard off the rev limiter. We'll go up to the rev limiter and it will oscillate a few times and it will basically just hold you at that maximum rpm limit until the driver commands a shift."
For many vehicles it would be a massive feat to harness 470 horsepower and 470 pound-feet of torque (Grand Cherokee SRT makes 465 pound-feet of torque) and put it to the ground. For the lineup of 2013 SRT vehicles, it's just another day at the office thanks to the A580 five-speed automatic transmission and its high-performance capabilities.