Question:My car doesn't have an air bag. Is there any
way I can install one?
Answer:Yes and no. You can now purchase an "aftermarket"
air bag to fit certain late model vehicles that did not come factory-equipped
with an air bag, but you can't install it yourself. It has to
be professionally installed by a trained technician.
Air bags do save lives, and are well worth the extra cost.
According to the Insurance Institute for Highway Safety (IIHS)
and the National Highway Transportation Safety Administration
(NHTSA), air bags account for a 25 to 29% reduction in moderate
or severe injuries compared to passive seat belts alone. IIHS
researchers have also found 24% fewer deaths than in cars equipped
with air bags than those equipped with seat belts alone.
Unfortunately, air bags were not offered as an option or standard
equipment until 1989. GM offered air bags as an expensive option
briefly back in the 1970s, but a low key marketing effort and
a lackluster reception by the public limited the number sold to
only about 10,000. So air bags bombed and were forgotten until
the federal government's decision to require passive restraint
systems (automatic seat belts or air bags) in 1990 touched off
a boom in air bags that brought the bags back.
In 1989, about half a million air bags were installed on new
cars. The following year, the number jumped to 3.3 million. By
1995, driver and passenger side air bags were standard in nine
out of ten new cars and light trucks. Federal law requires dual
air bags in all cars and light trucks by the 1998 model year.
If you have an older vehicle that does not have an air bag,
you can now have a driver side air bag installed for about .
The retrofit bags are manufactured by Breed Technologies Inc.
of Lakeland, FL, an original equipment supplier of air bag components
for seven of the top 10 best selling domestic-built vehicles.
BREED'S BAG
Breed's retrofit air bag is called the "SRS-40."
SRS stands for "supplemental restraint system," and
40 stands for 40 liters of gas displacement when the bag inflates.
The Breed air bag is a "European" style head and face
bag, which means it is designed to protect primarily the head
and face during a frontal collision. Most original equipment
air bags in domestic passenger cars, by comparison, are head and
torso bags designed to cushion the entire upper body. These are
larger bags and usually displace about 60 liters.
An important point to note about the Breed bag is that it
is designed to supplement the existing seat belts in a vehicle,
not to replace them. Nor is the SRS-40 system designed to be
a replacement for factory-installed air bags that have been deployed
in an accident. The Breed bag by itself does not meet the the
federal government's FMVSS208 passive restraint requirement, but
it does when used in conjunction with 3-point seat belts.
Crash tests show that factory 3-point seat belts do a fairly
good job of protecting the driver's body in a frontal collision,
but may not always keep the driver's head from hitting the steering
wheel (which can result in severe injury or even death). The
SRS-40 air bag is designed to provide additional protection to
the factory seat belts by adding an extra margin of safety. When
the bag inflates during a crash, it "fills the gap"
between the driver and steering wheel. The inflated bag provides
the cushion necessary to absorb the force of the impact and prevent
the driver's head or face from striking the steering wheel.
The SRS-40 bag uses similar technology the larger original
equipment air bags that Breed supplies to Jaguar and the '95 Jeep
Cherokee. It features a "mechanical" impact sensor,
which is the simplest, most reliable type of triggering mechanism.
Unlike most original equipment air bag systems that rely on
a complex web of crash sensors, safing sensors, wiring and an
electronic control module, the mechanical impact sensor is virtually
fail-safe. The crash sensor, which is self-contained within the
steering wheel air bag module, consists of a steel ball within
a tube. When a frontal impact of sufficient force occurs, the
ball is dislodged and slides down the tube, releasing a firing
pin that ignites the inflator. The bag deploys in 30 to 55 milliseconds
(less time than it takes to blink your eyes), which is just as
fast as an original equipment air bag.
Before the bag will deploy, the crash sensor has to experience
an impact force of about 7 G's (seven times the force of gravity).
For most vehicles, this would be the equivalent of hitting a
solid barrier at 12 to 15 mph, or hitting another vehicle at a
speed of about 25 mph. The actual crash speed at which the bag
will deploy depends on so many different variables (angle of impact,
the relative mass of the vehicle or object struck, the stiffness
of the body and chassis, etc.), that it's impossible to give an
exact speed. The only thing that can be said with certainty is
that the air bag will deploy when it is needed.
One of the advantages of having an air bag with a purely mechanical
crash sensor is that it eliminates the need for wiring and expensive
electronics. This allows the crash sensor to be packaged with
the inflator in the air bag module, which greatly simplifies replacement
and installation. It also means the system will function independent
of the vehicle's electrical system.
Because the SRS-40 air bag with its purely mechanical crash
sensor can be packaged as a self-contained unit, it can be easily
installed on just about any vehicle -- provided there's a steering
wheel available for the application designed to accept the SRS-40
air bag module -- and that the required crash testing has been
done to make sure the crash sensor has the correct level of sensitivity
for the vehicle.
Though it's relatively simple to replace a steering wheel
and bolt on one with an air bag, the SRS-40 isn't a "one-size-fits-all"
air bag. The bag has to "fit" the application, which
means different inflators and crash sensors are required for different
vehicle applications. An air bag with a crash sensor that's set
for a lightweight Toyota, for example, may not deploy at the right
speed if used in a heavier vehicle such as a full-sized Ford.
So Breed currently has five different inflator assemblies that
make up its SRS-40 air bag system.
To install the air bag, a technician selects the appropriate
module for the application, removes the stock steering wheel and
installs a new steering wheel that contains the air bag. The
entire job start to finish takes less than 30 minutes.
