Platform building. A modular platform will be central to PSA’s new model range, and key to the OEM’s plans for electrification. Words: Jesse Crosse.
TECH INSIDER / PSA CMP platform
Groupe PSA has revealed further details of its new CMP platform (Common Modular Platform), which will underpin compact A-C segment cars from the DS, Peugeot, Citroën, Opel and Vauxhall brands. The first car to be built on the platform is the DS3 Crossback compact SUV, which goes on sale in 2019. CMP will replace the PF1 platform and sit alongside the EMP2 platform launched in 2013, reducing the number of Groupe PSA global platforms from six to two. The existing DS3, which is still on sale, was launched on the PF1 platform in 2009. BEVs will be produced on a variant of CMP called eCMP, with the first – the DS3 Crossback E-Tense – due in 2019. Groupe PSA plans to launch seven electric vehicles on eCMP by 2021.
“The platform was conceived from the beginning to accommodate electric powertrains with no compromise on storage and occupant legroom,” says Eric Apode, senior VP, DS Automobiles. Internal space isn’t compromised thanks to the modular floorpan design, enabling the battery to be sandwiched in the floor of BEVs with an electric drive on the front wheels.
Most of the development was done at the Advanced Design Network facility in Vélizy and at Poissy in parallel with the development of the DS3 itself. The platform has been developed jointly with Chinese manufacturer Dongfeng. “One of the biggest challenges was achieving a worldwide launch of the new platform in our industrial plants throughout the world,” says Apode.
“We worked with all the major suppliers – Valeo, TRW, Bosch, Delphi, and so on,” Apode says. “All the big names are on our cards.” Aisin, for example, provided a new 8-speed transmission for the platform. The individual involvement of each supplier varied from model to model. Apode is quick to acknowledge the innovative capabilities of suppliers, but stresses that PSA works in conjunction with them to develop new features. “These are not off-the-shelf solutions,” he stresses. “We have the ideas and our suppliers have the capacity to realize what we want to do.
“CMP is a step forward from the previous platform and we have been able to reduce the weight by 20-30kg [44-66 lb].” Weight savings have been made through the use of high-strength steel, aluminum front subframes, and some use of composites. “The platform is 30% stiffer than previously, giving improvements in ride and handling,” Apode continues. The structure is welded and also bonded with around 22m (72ft) of adhesive per car. “The number of bolted parts has been reduced to reduce rattle and squeaks.”
All new DS models following the DS7 Crossback will be electrified, as either PHEV or BEV. “The DS7 Crossback PHEV becomes available in 2019 and will have an EV-only range of 50km [31 miles],” Apode says. “From 2025, I expect that one-third or more of DS sales worldwide will be electrified.” There will be no combustion-engine only DS vehicles after 2025 and PHEVs will be gasoline-electric only, so no more diesels from that time.”
Autonomous driving will play a major part in PSA’s future plans. “We strongly believe in autonomous driving and the DS3 Crossback will have the same Level 2 autonomous functions as the DS7,” continues Apode.
CMP platform chief engineer Eric Behr explains how some of the weight savings were made. “Combustion engine cars have an aluminum subframe that weighs 6-7kg [13-15 lb] less than that of the previous platform. The use of hot-stamped high-strength steel components in the main structure saves around 20kg.” The twist-beam rear axle of combustion engine cars is made from a new tubular structure design where the tube diameter reduces toward the ends, saving another 3kg.
The floor section module controls the wheelbase from model to model, and on BEVs contains the fully watertight battery casing. The 50kWh lithium-ion battery comprises 18 modules of 12 cells, each protected by a large shield underneath. BEVs have a different design of rear axle to maximize space for the battery between the two axles.
Behr estimates that several hundred people were involved in the development of the new platform, but numbers varied throughout the project. He agrees with Apode that global deployment across 10 different plants worldwide was a big challenge. “Highlights included the weight savings we were able to make and materials cost savings,” he says. Testing took place at PSA centers in France, Idiada in Spain, Finland and Sweden, with around 100 prototypes fitted with ‘top hats’ from the Peugeot 2008, mainly for validation and climate testing. Simulation played a major part in the development. “We continue to work toward more digital simulation, but we still need physical prototypes for validation,” he says.
The DS3 Crossback E-Tense BEV is front-wheel drive with a front-mounted motor developing 100kW/136ps. Power is drawn from a 50kW lithium-ion battery sandwiched in a BEV-specific floorpan. Acceleration to 62mph (100km/h) takes 8.7 seconds and 0-30mph (48km/h) takes 3.3 seconds. A full charge using an 11kW wall box takes five hours and an 80% fast-charge at 100kW takes 30 minutes. Range is 186 miles WLTP and 280 miles NEDC (300km and 450km).
- The first car to be built on the CMP architecture is the DS3 Crossback. The first BEV (built on the eCMP variant) will be the E-Tense
- The new strategy will see PSA reduce the number of platforms it uses from six to just two
- Eric Apode, senior vice president, DS Automobiles