Honda FCX concept fuel cell car in depth, Pt. 2 - Styling and powertrain

(Editor's Note: don't miss the Part One of this series)

The new Honda FCX concept is a four-door, four seat sports sedan with a profile reminiscent of the Lamborghini Portofino concept of the late 1980s. It has an extreme cab-forward stance, with a sharply raked windshield, and a fairly tall rear deck. The A-pillars stretch way out toward the front corners with a fixed quarter window between the pillars and the leading edge of the doors. This design element is also reminiscent of another late eighties vehicle, the unfortunate first generation GM mini-vans. However, on this car the whole design seems to work much better.

The roof line sweeps back from the front bumper to trailing edge of the trunk lid one continuous sweep. The total effect is futuristic and slightly aggressive. It definitely doesn't have the top-heavy, slightly clunky look of the current FCX. The 2008 production version will look almost identical to the current prototypes, the main difference likely to be in the front bumper area. The front styling is expected to be maintained but the structure will be modified.

(Continued after the jump)

The 2005 FCX power-train is on the left with the 2008 version on the right.

The insanely short nose is made possible by the redesigned and very compact power-train that Honda has devised. The previous FCX had the the electric motor and transaxle in two different planes. The new design has the gearbox and motor mounted in-line on the same axis, making the whole package almost nine inches shorter than the old one. In addition to being smaller the new motor is has an output increased from 107 to 127 hp. As with other electric power-trains, the gearbox is just a reduction gear-set, but is otherwise direct drive.

Under the hood of the 2005 model.

The fuel cell power-plant is 400 lbs lighter than the unit in the 2005 model. One of the pitfalls of previous fuel cells has been cold-weather start up performance. The Ford Focus FCV that was recently evaluated here needed to be kept above 40 degrees Fahrenheit to start. The 2006 FCX can start up at -4F and the new car with the vertical V Flow fuel cell stack can start-up at -22F. The current model also uses an ultracapacitor instead of a battery. The new version is equipped with a newly designed lithium-ion battery pack to supply supplemental power and also to run the air compressor necessary to get the fuel cell started. The battery is 40 percent lighter and 43 percent smaller in volume than the ultracapacitor while having much more power capacity.

The electro-hydraulic brake unit.

The battery gets recharged by a combination of the fuel cell and regenerative braking. The regen braking is accomplished thanks to an electro-hydraulic brake system that handles the blending of regen and friction braking. In place of the electrically powered vacuum pump used for brake assist on the current car, the new one features hydraulic brake boost. Unlike some systems that integrate the booster with the slip control system, this one uses two separate units. The brake system includes disc brakes at all four corners with an electronic park brake system all suspended by double wishbones in the now classic Honda configuration.

For fuel storage, the new car replaces the two smaller hydrogen cylinders of the current car with a single larger capacity tank. Capacity of the tank is now 4kg (8.8 lbs) of hydrogen gas at 5000 psi. The combination of increased fuel capacity and more efficient powertrain yields a thirty percent improvement in range compared to the 2006 model. The current car goes 210 miles on the EPA combined test mode while the new one goes 270 miles and is expected to improve even more by the time production starts in 2008.

(Up next, the interior and construction
of the FCX)

The H2 tank is under the panel labeled FCX Concept in the trunk.

The back end of the 2005 FCX.

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