[engine roaring]
This is the longest jump ever made
in the World Rally Championship.
278 feet.
That's nearly the length
of a football field.
[engine roaring]
That massive jump was done by this car,
a Citroën C4,
a simple European compact car
known for its safety and reliability.
But how do you send an
average economy car into orbit
and safely back down again?
You transform everything
that makes it an average car.
The first important difference
between rally cars and road cars
is a more aerodynamic design
that makes flying through the air
a whole lot easier and safer.
Let's compare a rally car
like Hyundai's i20 WRC model
and the automaker's i20
compact car that it's based on.
Besides both being built
on the same steel shell,
one screams "racecar"
while the other screams "new parents."
But those eye-catching additions
aren't just for show.
Once the i20 takes flight,
its aerodynamic additions
make sure it comes back down
as soon as possible
and on its wheels.
This requires creating downforce,
the downward vertical force on a car
that keeps it glued to the ground.
In a sport like IndyCar racing
that takes place on a smooth, flat tarmac,
creating downward force is important
for simply giving racers
more grip in tight corners.
But in rallying,
where there's constant elevation changes
on loose gravel and snow,
downforce keeps cars from
flying off the track.
To generate downforce,
rally cars like Hyundai's i20 WRC
are fitted with sloped carbon-fiber wings
throughout the body.
While most obvious is
the 6-foot-long one in the back,
there are also small wings
positioned over the wheels.
These are known as dive planes.
Although they may be a
different size and shape,
their function is the same.
As the car drives forward at high speed,
it has to cut through air.
High-pressure air forced
under the car creates
an upward force on the
vehicle known as lift.
The wings counteract
this lift with downforce.
Incoming air forced over
the car is slowed down
and pushed upward by the wings.
The equal and opposite reaction
is slower-moving high-pressure air
now pushing the car downward.
This is the downforce needed
to keep the car properly balanced.
This downforce is
especially useful for jumps.
In a rally car that constantly
finds itself in the air,
having plenty of downforce to stay level
and coming straight back
down on all four wheels
is especially important.
Just ask driver Petter Solberg,
who lost his rear wing in
the 2005 Rally Finland.
But even if you can send a car
flying into the air
level and straight down
on all four wheels,
it means nothing if that car doesn't have
a suspension that can handle the landing.
That's why the suspension
that ends up on a WRC rally car
looks nothing like what you'll find
on your typical road car,
especially the dampers.
On a regular road car,
every time your car
bounces over a rough surface
or hits a nasty bump,
the intense energy and
vibrations on your wheels
are absorbed by a large coil spring.
But while those springs
are great at absorbing energy,
they need something in the way
to keep them from bouncing
back uncontrollably,
like a trampoline.
That's where dampers come in.
Positioned inside the spring,
they're made up of a long, telescopic body
with a piston and oil inside.
As the spring compresses
during a heavy bump,
so does the damper,
and that piston slides
down through the oil.
As the spring bounces back,
the damper is what keeps it under control.
The oil slows down the piston's return
and converts that energy into heat.
On a road car,
the goal of the suspension and dampers
is to keep the ride as smooth
and comfortable as possible.
Ideally, so you barely
notice those bumps at all.
But on a WRC rally car,
comfort is the engineers' last concern.
There's no question there
are bumps and bangs coming.
You've got 1.2 tons of metal
crashing down from heights
of over three yards.
The goal is for the car to survive
and keep going as fast as possible.
This calls for dampers
twice as big and strong
so they can handle more
intense compression.
They're built thick, heavy,
and tuned with the intention
of absorbing an enormous impact,
not making sure the passengers are cozy.
A motorsport like rallying
also requires an additional canister
connected to the damper.
In an especially active damper,
oil temperatures are reaching
up to 248 degrees Fahrenheit.
This can cause your shock
absorbers to overheat,
which leads them to
compressing irregularly
and the driver losing
control of the vehicle.
An additional canister,
or remote reservoir,
allows you to carry more oil
and have a place where it can cool down.
The most crucial feature
rally car dampers have, though,
is how adjustable they are.
With knobs found on both the dampers
and throughout the car,
everything from ride height
to compression speed can be adjusted.
For rally courses that feature more jumps,
drivers need a car that's
both higher off the ground
with a suspension that they can count on
bouncing back immediately.
But even if your car has the aerodynamics
to soar through the air smoothly
and a suspension that
can handle the landing,
it's going to mean nothing
if your car's undercarriage
isn't protected properly.
The undercarriage has
many exposed components,
like fuel lines that are easily penetrable
by sharp rocks and race debris.
So the i20 WRC is fitted with
quarter-inch-thick steel plates
bolted to the underside of the car.
Known as skid plates
or sump guards,
their main objective is to protect
the oil pan, transmission, and fuel tank
from loose stones and debris.
Skid plates help drivers
against a number of major car problems,
the most dangerous being
fuel and oil leaks.
While these two issues
usually just result in engine failure,
they have also caused a number
of major fires in the WRC.
Esapekka Lappi's unsolved car fire
at March's Rally Mexico
is believed to have been
caused by an oil leak.
Skid plates drastically improve
your chances of avoiding them.
Still, the skid plate alone
can't protect you from everything.
Just ask driver Elfyn Evans,
who landed on nothing but his skid plate
at last year's Rally Estonia
and suffered two compression fractures.
No matter how prepared you may be,
some rally car disasters
are just unavoidable.
So while cars only take to the air
in NASCAR and Formula One
after something has already gone wrong,
in the World Rally Championship,
it's a major part of the competition.
Between being equipped
with an aerodynamic body,
heavy-duty suspension,
and a steel-plated undercarriage,
jumping nearly the length
of a football field
is something these incredible vehicles
can handle day to day.
While they may be based on compact cars
that can barely handle a pothole,
the right kind of engineering
can transform them from family vehicles
into high-flying tanks.
