Getrag brought several compelling new technologies to the Magna fold in last year’s acquisition, but Magna’s powertrain engineers have been busy on many fronts. For instance, the eTelligentDrive system makes EVs a whole lot more fun to drive.
Magna’s Thomas Holle discusses new hybrid DCT.
Table of Contents:
- Hybrid DCT, Torque-Vectoring EV In Magna Product Plan
- Tesla Model S Adapted For Torque Vectoring
ARJEPLOG, Sweden – From a 7-speeddual-clutch hybrid-electric transmission to a 3-motor electric-axle layout enabling torque vectoring and improved dynamic handling for battery-powered cars, ’s powertrain division is preparing for the next generation of sophisticated propulsion systems.
acquired transmission specialist just last year, and already the company is shopping to potential automaker customers prototype cars integrating the latest Getrag transmissions, such as the new 6MTI550 manual for torque applications up to 590 lb.-ft. (800 Nm).
Installed on a340i, the 6MT is intended for low-volume inline engine applications and is compatible with all-wheel drive and stop/start systems. Maximum input speed is 7,000 rpm, and Magna says the modular design can be scaled for torque density, gear number, spread and synchronizer technology. The transmission also is suited for light-duty commercial vehicles.
Also available during recent test drives in Arjeplog, Sweden, was a series-productionMégane IV with a Getrag dual-clutch 7DCT300 transmission, which was designed for high fuel efficiency and to accommodate torque up to 236 lb.-ft. (320 Nm).
The 7-speed DCT works with most front-transverse engines and stop/start, consumes little power, mates with AWD, integrates a mechanically actuated parking brake and can achieve a gear ratio spread as high as 8.5.
The FWD Mégane IV, with a 1.6L 4-cyl. and an open differential, launched this year with the Getrag DCT, but the transmission first appeared in the largerEspace in 2015.
The Mégane test drive was intended to demonstrate the three available modes that change drivetrain behavior. On the open road, switching between Sport, Neutral and Comfort modes significantly alters the drive experience. That flexibility is much more difficult to achieve with a conventional automatic transmission with a torque converter, Magna engineers say.
In comfort mode, upshifts with the Getrag DCT occur quickly, at low engine speeds, improving fuel economy and ensuring ultra-smooth cycling through gears. The driver arrives in fifth gear without even realizing it.
In Sport mode, the DCT holds gears longer, allowing the engine to rev higher and route more power and torque to the road. The two wet clutches enable much quicker shifting: 200 milliseconds in Sport, compared with up to 350 milliseconds in Comfort. In all modes, the DCT will downshift up to three gears, depending on pedal position and vehicle speed.
“We don’t use a classical hydraulic system for this transmission,” says Thomas Holle, Magna Powertrain teamleader for transmission testing.
“We use smart actuation that combines small electric motors and small pumps for each clutch. Each single clutch has its own e-motor pump system, an on-demand actuation pump. We only need to turn the electric motors when we need to keep a clutch closed or change status of the clutches.”
The next step is to further electrify the DCT for hybrid applications by integrating within the transmission housing an electric motor rated as low as 15 kW for stop/start and up to 75 kW for a plug-in hybrid, Holle says.
“And the installation length will not change for the (OEM) customer,” he says of the hybrid DCT, which is 14.5 ins. (369 mm) long. “It’s easy for the customer to build up a platform” with either the DCT or hybrid HDT version.
The hybrid transmission integrates all the necessary cooling, power inversion and electronic controls.
Estimating the fuel-economy gain with the hybrid transmission depends on battery size and other parameters, but Holle says an automaker could see a 20% reduction in fuel consumption relative to the standard non-hybrid DCT.
The hybrid transmission weighs about 198 lbs. (90 kg) while the non-hybrid DCT weighs in at 148 lbs. (67 kg), Holle says.
The hybrid version is intended for FWD architectures, but Holle says Magna is considering adapting it for AWD.