It’s the same rear-wheel-drive transmission Ford’s been chatting about, too, lately, and that’s no coincidence. The two automakers developed it together. Ford’s introducing it in the 2017 F-150. GM will debut it in the 2017 Chevy Camaro ZL1.
GM claims the new rear-wheel-drive gear box will increase fuel economy and performance with a wider overall gear ratio spread of 7.39, a short first-gear ratio of 4.70, a tall top gear, and shorter, quicker jumps between gears. The gear steps are so small, the ZL1’s supercharged engine can deliver optimal power all the time during upshifts. GM says it’s especially true when exiting a corner on the track.
It’s also been specially calibrated to make the ZL1 “angry”.
“The gear ratios are so tightly spaced that the transmission is in the right gear and the engine is at the best rpm for transitions from corners to straights,” says Aaron Link, the Camaro’s lead engineer. “And with the power from the ZL1’s supercharged LT4 engine, the force you feel in your seat as you accelerate out of a turn will put a grin on your face every time.”
By the way, the ZL1’s supercharged 6.2L LT4 engine delivers an estimated 640 horses and 640 pound-feet of torque.
Chevy says its tests show the 10-speed equipped ZL1 shifts faster between the first four gears of Porsche’s PDK dual-clutch transmission. The 1-2 upshift is 36-percent quicker than the PDK, while the 2-3 and 3-4 upshifts are 27-percent and 26-percent quicker, respectively.
“You touch the paddle and the gear changes with immediacy,” said Link. “The shifts happen so quickly and without delay that it almost feels like an extension of your reflexes. It’s a much more involving experience for the driver that really helps improve confidence and performance on the track.”
The 10-speed also has a numerically lower top gear ratio than Camaro’s eight-speed automatics, so the engine can run at a lower speed on the highway making it more efficient. It’s designed with four simple gearsets and six clutches: two brake clutches and four rotating clutches. That’s only one more clutch than the eight-speed, despite having two more forward gears. (It’s also about the same size at the eight-speed.)
The new gear box will be produced with an all-new manufacturing system at GM’s propulsion manufacturing facility in Romulus, Michigan. GM plans to introduce it on eight vehicles by 2018.