Honda recently invited us to its research center and test track at Tochigi, Japan, to preview a number of powertrain technologies the company is working on and which will likely see production in the future. While we can only offer limited evaluations based on our one- or two-lap track test drives, we can give you an idea of what to expect from Honda’s future cars. Test drives included Honda’s new line of turbocharged three- and four-cylinder engines, a new eight-speed dual-clutch transmission with torque converter, a steer-by-wire system and a prototype vehicle built from lightweight carbon-fiber composites rather than aluminum and steel. All of these technologies are prototypes and are not production-ready.
1.0-liter Turbocharged Inline Three-Cylinder Engine
Envisioned as a
replacement for small, naturally aspirated four-cylinder engines, this
turbocharged I-3 makes 127 hp and 148 lb-ft of torque. That’s more than
the 117 hp and 106 lb-ft from the 1.5-liter I-4 of the outgoing
U.S.-spec Honda Fit. The difference is, the turbocharger gives this
engine a better torque curve with more mid-range punch, so drivers won’t
have to absolutely wring it out to get good acceleration.
We sampled this engine in a European-spec Civic
hatchback, where it performed comparably to any other Civic-sized car
currently on the market. Overall acceleration was about the same, but
accelerating in gear, such as to pass, was improved thanks to the turbo
torque. Top-gear acceleration, such as passing on the highway, was
pretty good, though you needed to floor it to really move. The engine
was generally quite smooth with very linear power delivery.
On the down side, this particular engine was in
need of some more fine-tuning, as it would occasionally surge rather
than accelerate linearly. A Honda engineer assured me, naturally, that
this issue would be eliminated before the engine goes into production.
1.5-liter Turbocharged Inline Four-Cylinder Engine
Like the
three-cylinder, this turbocharged four is meant to replace a larger
four-cylinder engine, say something in the 2.0-2.5-liter range. With 201
hp and 192 lb-ft of torque onboard, it’s well-positioned to do that.
Like the three-cylinder, this engine feels comparable in total
performance to the engine it’s trying to replace but offers more punch
in the mid-range. It also delivers very smooth, linear power. Go all
the way to the floor and it’s even reasonably quick in a midsize sedan
like our Accord tester.
On the not-ready-for-production side, we noticed
the engine was rather loud under acceleration and could be coarse at
low RPM, just off idle. We also noticed that our CVT-equipped tester was
cruising at 70 mph at 2200 RPM, which seemed at least 500 RPM high.
Honda again assures us these issues will be addressed.
2.0-liter Turbocharged Inline Four-Cylinder Engine
This engine is a
different story. While it may be called in the future to replace a V-6
engine, our test vehicle was a European-spec Civic Type R and it was
tuned for performance, full-stop. And what an engine it is!
With “275+ horsepower” and 295 lb-ft of torque
onboard, this car was a riot. Hit the “R” button on the dash and at any
RPM you get an impressively strong push back into the seat. That a
turbo-four could feel this strong makes you giddy, and you keep flooring
it just to get that rush again. The engine revs very quickly and pulls
evenly all the way up the dial. In-gear acceleration is strong, but
you’ll want to downshift just for that extra pull.
If we had complaints, they would be that it
torque-steers a bit when you launch hard. Another is that the throttle
is too sensitive in R mode. We also noticed the exhaust was a bit dark,
meaning the engine will require more tuning to meet emissions
regulations, which we hope won’t spoil the power delivery. We very much
hope to see this engine just as it is in a U.S.-spec performance model
as soon as possible.
8-Speed Dual-Clutch Transmission with Torque Converter
This sounds odd, so
let us explain first. This transmission uses both a torque converter
and a dual-clutch system. A typical dual-clutch transmission replaces
the torque converter with twin wet or dry clutches. Honda’s transmission
instead leaves the torque converter where it is and places the clutches
on the two gear shafts, each controlling half the gears. Honda says
this was actually quite easy to do because its automatic transmissions
never used planetary gears but were more similar to automated manual
transmissions, but with torque converters instead of dry clutches. This
new unit actually weighs about the same as Honda’s old five-speed.
The reason for all this complexity is to get
best-of-both-worlds driveability. While DCTs shift faster than
conventional automatics and tend to be more efficient, they struggle
with vibrations and smooth clutch engagement when starting from a stop.
Honda therefore kept the torque converter and uses it to move the car
smoothly away from a stop like an automatic would. The torque converter
then quickly locks up and the dual clutches take over and do all the
shifting. Thus, you get smooth launches and super quick shifts, as well
as better efficiency.
In the real world, the prototype delivered on its promises. Leaving a
stop was no different than any traditional torque converter automatic,
with smooth acceleration and no hint of chatter or balkiness from the
transmission. Once under way, the transmission changed gears lightening
quick and so smoothly that we almost couldn’t feel them happen. Response
to the paddle shifters was nearly instantaneous as well.
This prototype struggled, though, with some
downshifts. While some were smooth, others were harsh and abrupt.
Engineers grimaced and admitted the software needed more work to
eliminate those instances. Absent that problem, this transmission seems
almost ready for prime time and could offer a compelling alternative to
balky DCTs and slow-shifting automatics.
Steer-By-Wire
With the advent of
electric power-steering racks, steer-by-wire is the next logical step as
cars incorporate more safety systems and we advance towards autonomous
driving. Disconnecting the steering wheel from the steering rack allows
automakers to reduce vibration transmitted into the cabin as well as
correct for crowned roads and crosswinds, or simply steer autonomously,
all without the driver knowing it.
Honda’s solution is a very good one. It’s first
time out the door and still a prototype, but based on our time in the
test car, Honda’s unit is hands-down better than Infiniti’s
much-maligned (but recently updated)
production system in the new Q50. Driving around a tight winding track
in an otherwise stock Accord sedan, it feels barely any different than
any of the regular electric power-steering systems found in production
cars today. The only really noticeable difference is the complete lack
of steering feedback and feel, as Honda hasn’t tried yet to simulate
road vibrations in the steering wheel.
Steering response, even when driving hard, was
very linear and it always felt like we were getting exactly the amount
of steering at the wheels as we were commanding at the steering wheel.
The steering wheel felt nicely weighted for a family sedan and the
weight built naturally with steering input. In short, it felt like
driving any other family sedan.
Aside from the lack of feel, the only other
drawback was a lack of reaction during understeer. Normally, steering
wheels tend to get light when a car understeers and you can feel the
lack of grip. When pushing this prototype to the point of understeer,
there was no change in the steering weight to signal that the front
tires weren’t gripping. We hope Honda decides to simulate that effect in
the future so that drivers will be more aware that they’ve exceeded the
limits of grip.
Super Light Structure
Like all
automakers, Honda is aggressively researching weight-saving
technologies, as weight is the enemy of performance and efficiency.
Naturally, that means the company is researching carbon-fiber and
carbon-fiber reinforced plastics (CFRPs) as ways to bring down weight
without sacrificing strength and, ultimately, crashworthiness.
To illustrate what they’ve learned so far, Honda
built a CR-Z hybrid on an all-new carbon-fiber monocoque tub with
aluminum sub-frames for the engine and front and rear suspension. Though
not a drop-in replacement for the standard metal frame, the new
carbon-fiber tub weighs just 176 pounds. Replacing the metal body panels
with carbon-fiber and glass-fiber-reinforced thermoplastic pieces cut
the weight of the body in half. The lighter-weight body and frame then
allowed Honda to reduce the size of the wheel hubs, brakes, wheels and
steering system as well, and further savings could be found in smaller
tires and a smaller drivetrain. In total, Honda took 661 pounds off this
CR-Z, a 30-percent reduction compared to stock. The engineers say
that’s good for a 30-percent improvement in zero-to-60 mph acceleration
and a 20-percent improvement in fuel economy, jumping it to a combined
40 mpg on the U.S. test, up from 34-37 in production cars today. We've
tested manual-transmission U.S.-spec CR-Zs accelerating from 0-60 mph in
8.3 and 8.4 seconds.
Of course, this test car is a long way from
production. The massive side rails of the tub make the door sills very
high, so Honda installed what amount to power-operated T-tops in the
roof to make more room for entry and egress. The seat is a racing bucket
and the interior is only half-present. But, Honda says, it has a
bone-stock drivetrain. That’s impressive, because it feels a whole lot
quicker than stock.
Not only is
straight-line acceleration improved, but throttle response is better
across the board. Whether making a pass or powering out of a corner, the
car feels like it has much more power and a more linear delivery. Upon
entering those corners, the car feels more nimble and balanced, changing
directions very quickly and in total control. We were able to place the
car exactly where we wanted it on the road thanks to our confidence in
its super predictable handling and response. It’s a shame this exact car
won’t ever be for sale, as it’s a very fun little sports car very much
in the vein of the vaunted Subaru BRZ.
While we may not get this exact car, don’t bet
against seeing carbon-fiber technology in future Hondas. The engineers
say they’re working on ways to speed-up and automate the construction
process to make it viable for mass production. Currently, carbon-fiber
must be laid by hand in a time- and labor-intensive process.
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