CAR and Driver - March 2017

SARTORIAL SENSING

HITOE SENSOR SHIRT

With most big-time series

now regulating the amount of

testing, teams use every

on-track moment as an oppor-

tunity to collect data. Even the

driver has now become a data

point. A Japanese electronics

and textile firm jointly devel-

oped Hitoe, or “one layer,”

a flexible, breathable material

in which the fabric nanofibers

are coated with a conductive

polymer able to transmit

electrical signals. A fireproof

version has been tested in

IndyCar and was able, despite

g-loadings and copious perspi-

ration, to transmit data to the

team on the driver’s heart rate

and regularity. The shirt also

delivered a continuous electro-

myogram, which measures

the neurological activation of

the muscles. The data showed

that, at times, a driver is

working about as hard as a

sprinting runner, information

that could help drivers extract

even more performance from

their g-loaded bodies. With

wider tires coming to Formula 1

in 2017, the g squeeze is on

more than ever. Such clothing

may someday tell your Toyota

Camry about your fading pulse

rate and drowsy eyes and

prompt it to act.

EFFICIENT RUBBER

Michelin Pilot Sport EV2
Tire Basics 101 teaches that as grip goes up, so does rolling resistance, which
negatively affects fuel economy. Racers, however, like car companies, want
more grip with less resistance. Michelin, the supplier of the Pilot Sport EV to
Formula E, claims to have delivered just that, reformulating the grooved spec
tire with new compounds and construction that should increase corner speed
while reducing rolling resistance. How? Michelin won’t say, exactly, but hints
can be found in the new Pilot Sport 4 S, announced last fall as a replacement for
the Pilot Super Sport. The 4 S shares an almost identical tread pattern with the
racing Sport EV2, which is unlike most racing tires in
fitting an 18-inch rim and otherwise having road-car
dimensions. A new type of construction strategically
places the grippiest rubber compound only where it’s
needed, and the reinforcing strands of belt material
preserve the shape of the tire so that those compounds
do the bulk of the cornering work while standing by on
straights. For greater endurance, the design also better
distributes over the whole tire the heat generated by
cornering loads. That’s about all we can say, since at
Michelin, the secret sauce is so secret that the company
no longer patents its best discoveries.

FIRE IN THE HOLES

Turbulent Jet Ignition
Exactly what goes on under the carbon-fiber shell of a
Formula 1 car is a matter of guesswork for observers, but
they should know that it’s all about saving fuel. For a while
last season, rumors persisted that Mercedes AMG
Petronas, among others, was using homogeneous-
charge compression ignition, or, essentially, com-
busting gasoline as if it were diesel under certain
conditions and as a spark-ignited engine the rest of
the time. Then it emerged that the team was actually
onto something new, called Turbulent Jet Ignition,
which extracts more energy from the fuel similar to
Honda’s old Compound Vortex Controlled Combus-
tion from the 1970s. For now, this is racing-only tech,
since at the much lower speeds and power loads that
road cars run, the combustion isn’t stable.

(^3) Burning fuel exiting the prechamber through four to eight tiny orifices initiates combustion of the
main fuel-air charge. The resulting flame front spreads quickly through the combustion chamber,
allowing a much leaner overall mixture and improved fuel efficiency.
Tony Kanaan debuted
the Hitoe technology
during the 2016
IndyCar Series.
Smart
clothing:

• The Heddoko
  athletics shirt’s
  motion-capture
  sensors create a
  3-D model of your
  movements on
  your smartphone
  so you can run
  or work smarter or
  strike the perfect
  Warrior II pose.


• Ralph Lauren
  makes smart clothes
  fashionable with the
  PoloTech Shir t, the
  interwoven silver
  fibers of which report
  biometric data to
  your iPhone or Apple
  Watch to track
  calorie burns and
  workout intensity.


• The Gymi Smart
  Shirt from Australia
  has sensors that
  can track your reps
  and sets for the
  perfect pump.

063

Formula 1 peak

fuel consumption:

2005 McLaren MP4-20

Mercedes-Benz FO 110 R V-10

69.0 gallons/hour

2016 AMG Petronas F1 W07

PU106C V-6 hybrid

35.6 gallons/hour

MOST IMPROVED
RACER
The second-generation
Michelin Pilot Sport
EV2 is vastly improved
over the Pilot Sport
EV from the 2014–15
season.
–11 pounds
(set of four)
–16% rolling
resistance
+1.2 miles of range

(^2) A conventional
injector sprays
most of the fuel
during the intake
stroke. The
remaining 5
percent or so is
sprayed into the
prechamber by
the secondary
injector, yielding
a super-rich
mixture that’s
easily ignited by
the spark plug.
(^1) TJI engines
have a small pre-
chamber above
the combustion
chamber where
both an injector
and a small spark
plug are nestled
to geth e r.
Pilot Sport EV2
Pilot Sport 4 S