NOT having to engineer a large, reinforced hole in the front of your car’s chassis for a heavy, hot, vibrating internal combustion engine (ICE), and a hump down the middle for a transmission, opens up a whole range of possibilities.
With the global transition to EVs gathering pace, automotive engineers and designers are no longer locked into a certain set of ICE chassis design parameters that have prevailed for more than a century – because EVs require a completely different set of rules.
An electric motor is smaller than an ICE, generates less waste heat to manage, does not need a gearbox in the accepted sense, nor a clutch, tailshaft, separate differential or a whole range of other ‘redundant’ components associated with ICE power.
While some car-makers are adapting existing ICE vehicle architectures for electrified applications, others including Hyundai Motor Group are moving on to purpose-designed EV platforms that make more economic sense.
Hyundai’s Electric Global Modular Platform (E-GMP) is tailored specifically for EVs and is already under cars like the Ioniqs 5 and 6, Kia EV6 and Genesis GV60. Many more will follow as the South Korean manufacturer switches over to primarily EV production.
“Whether it means installing a workstation or zero-gravity reclining seats for a near horizontal recline, with E-GMP you can create a memorable in-car experience, using space as you see fit,” Hyundai Australia product planning manager Luke Croucher told GoAuto at the recent Genesis Electrified GV70 launch.
“We have announced that Ioniq 7, a seven-seater SUV, will be the next Ioniq model and it will show the platform’s adaptability.
“The E-GMP platform supports a wheelbase exceeding 3000mm that in turn supports various sizes and configurations of vehicles including C-segment, E- Segment, CUV, sedan and SUV (up to three-row SUVs with seven seats).
“It is a very rigid structure that delivers benefits across the spectrum including ride and handling, noise abatement and safety.”
In contrast to an ICE platform, a dedicated EV architecture like E-GMP or VW Group’s modular electric drive matrix (MEB) are only required to house a battery pack, high-voltage electronics and associated thermal management systems along with allowances for the motor (that can be in-wheel like an electric scooter) steering, suspension, brakes, ancillaries, axles and wheels.
They are modular, have standardised components for cost control, can be scaled to suit many different applications and are manufactured to optimise space, safety and the amount of materials used.
Although modular platforms have been an integral part of car-making for decades, for ICE vehicles they are more complex, costly and more difficult to adapt for different vehicle types.
In designing the E-GMP, Hyundai prioritised a number of factors: Performance, modularity, reliability, safety and useability. The company says it is on track to achieve its stated objective of having 23 new EV models in the line-up available by 2025.
The E-GMP’s proportions are radically different to what underpins equivalent ICE vehicles, meaning the cabin has a larger, flatter floor space that allows Hyundai to best configure the interior to meet each segment’s needs and create vehicles that fit various uses or lifestyles.
Drive motors sit low in the chassis at the front or rear in line with the driven axles and underfloor sandwich battery pack. The layout has benefits in terms of lowering the centre of gravity, aiding weight distribution and simplicity of design. Extending the wheelbase is simple as it only requires extending the middle floor area, which then creates more battery space.
“The battery is attached to the full-perimeter frame using eight bolts running completely through the battery for strength. The front and rear crumple zones are designed to absorb and dissipate the energy of a potential impact, and high strength steel is used to protect the battery and passenger compartment,” said Mr Croucher.
By standardising the battery cell and module into a single unit, E-GMP has simplified battery repairs, meaning damaged batteries no longer need to be changed out as a whole – only individual malfunctioning modules need to be fixed or replaced, reducing the cost of repairs for customers.
Medium and large Hyundai vehicles will use the E-GMP dedicated EV platform featuring a rear suspension that uses a five-link arrangement with integrated drive axle, where the drive shafts and wheel bearings are a single unit to reduce the number of parts and increase rigidity.
However, covering off all options, Hyundai R&D advisor Albert Biermann has stated that "existing EVs on ICEV platforms will see some expansion into smaller segments", suggesting Hyundai’s smaller EVs – such as the Kona – would continue to use a legacy front-wheel drive platform for the time being.
In related information from its head office, Hyundai says; “Liberating more interior room, the ‘space consuming’ air conditioning unit is moved outside the car and is placed where the ICE engine would be, giving front passengers extra room.
“Further, the centre tunnel at the rear (seen on conventional vehicles) is non-existent thanks to the low mounting position of the batteries. This will also allow various arrangements of the front and back seats for a variety of applications.” It’s still possible to offer a boot at the front and back.
“The modular nature of the chassis means it is highly adaptable and saves on production complexity and therefore cost. That wouldn’t apply to the existing GV70 platform, which is not modular.”
Hyundai places great importance on E-GMP and has accelerated its integration. It will be the backbone of EVs made by Hyundai, Kia and Genesis in future as it offers optimal EV performance and parts standardisation.