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FEBRUARY 2002
VTECH HELPS
HYBRID
Honda has found another application for its unique VTEC valve-timing system.
Normally used in its performance engines to switch from a moderate camshaft
profile at low revs to a wilder one for maximum power at high revs, the
new Civic IMA hybrid (integrated motor assist) uses VTEC to close the valves
in three out of four cylinders when the car is lowing. Instead of selecting
alternative cam profiles, it deselcts them completely. That reduces engine
braking, allowing the electric drive to work harder slowing the car, thereby
generating more electricity and charging the batteries in the process.
RANGE ROVER STEELS THE SHOW
Land Rover's new independent suspensin set-up on its new Range Rover incorporates
an air suspension system that raises the SUV's ride height when it senses
rough ground; and that helps it cope with ground clearance problems not
experienced by the old-type live axle. The enormous rear arms are also massively
heavy because they're made of steel rather than aluminium. "Aluminium
is not strong enough,"
says chassis engineering manager, John Batchelor. "Off-road, the whole
weight of the vehicle can be taken on one component and aluminium is too
brittle."
JANUARY 2002
W12 IS VALID OPTION
Ulrich Eichhorn, head of VW R&D, says the record-breaking 6.0-litre
W12 supercar doesn’t conflict with the need to reduce emission and
fuel consumption across the board. “In terms of a couple of hundred
cars it does not affect us at all,” he says. The 100bhp-per-litre W12
does not feaure fuel-saving details like the cylinder cut-out favoured by
Mercedes for its big vee engines. “I’m not convinced (the cut-out)
is valid.” says Eichhorn. “It works better on engines that do
not breathe as well as a high-performance engine like this.” Eichhorn
says that if the board were to approve production, the first cars could
be ready within two years.
TYRES GET SAFER
A joint development will warn drivers of low tyre pressures and/or excessive
tempe-ratures. Tyre manufacturer Goodyear will concentrate on the technology
surrounding tyre engineering, pressure monitoring, embedded sensors and
interpreting the connection between tyre temperature and pressure. Siemens
VDO will provide expertise in electronics, radio transmission and integrating
systems into the vehicles. No launch date has been announced yet but both
companies are reported to be giving the project high priority.
12V BRAKE-BY-WIRE
Delphi’s prototype drive-by-wire brakes - which have reached an advanced
stage - work using a normal 12-volt electrical system, when it had been
assumed that 42 volts would be needed to provide enough power. Each caliper
contains a small motor and gear mechanism which presses the brake pad hard
against the disc. It’s simple, but, says a senior Delphi engineer,
the skilled work was designing an efficient mechanism fast enough to meet
the demands of ABS. Testing on a Peugeot 206 fitted with the new brakes
is currently underway.
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