Does
this sound familiar?
A driver towing a heavy load or driving a big motorhome has
finally made it – he has crested the top of that mountain grade
and it’s all downhill from here. He peers down the highway in
front of him running down the side of the mountain and realizes he
has a new set of challenges.
He has a four mile, seven percent grade to
navigate with tons of metal riding behind him and all he has are a
set of overworked vehicle brakes to slow his growing momentum as
he starts to gain downhill speed without so much as a tap on the
throttle.
He looks to his right over the edge of the
guardrail and can’t see the bottom! Returning his gaze to the road
in front of him he sees, becoming clearer every moment, a line of
vehicles at a stop sign at the bottom of the hill. And all of a
sudden there are butterflies coming to life in his stomach and
they are beating their wings furiously.
The driver realizes he is in a "free fall" with no
speed retarding assistance from his engine, so he begins to pump
the brake pedal. While he feels some temporary assistance, and a
little security from knowing he is no longer rocketing down the
side of a mountain, he notices that the blood is leaving his
knuckles as he grips the steering wheel. He downshifts and his
RPMs begin to soar, but his speed continues to increase. So as the
skin covering the back of his hands becomes almost transparent, he
decides to take the next step – the final option.
He stands on the brake pedal with such force that
he lifts himself out of the driver’s seat far enough to slip a two
by four between him and the upholstery. Finally, his momentum
begins to slow – a little. Now his sense of smell kicks in and as
he sniffs the air, he smells something. What is that? Can a person
smell heat? It sure seems like something is burning and he
recognizes the pungent odor of overheating brakes.
As his brakes begin to roast, they also begin to
fade and lose braking effectiveness. The driver realizes that he
is driving on a wing and a prayer, and he hopes for the best as
his lively descent down the mountain grade continues unabated.
Why do these problems occur?
A new diesel owner, especially one who is unfamiliar with the
difference between how a diesel engine works compared to the
gasoline engine he is used to, may be unprepared for the braking
challenges presented by his new fuel-efficient, cost-saving
diesel.
At its very center, the problem arises from the way the engine
runs when there is no pressure on the throttle. When a gasoline
engine is idling, the throttle body butterfly rests in a closed
state. The butterfly cuts off air flow so the engine generates
vacuum as the pistons are continually trying to draw air into the
cylinders. This vacuum has a retarding effect on engine output and
automatically provides some braking assistance on downhill grades
when the driver’s foot is not on the throttle.
This butterfly-generated vacuum assistance does
not exist in a diesel engine. Even when there is no throttle
pressure, the diesel continues to pump air into the engine.
Is there a solution to fix this problem?
Yes! For decades, big rig drivers have used engine brakes and
exhaust brakes to restrain the engines in their heavyweight diesel
tractors. Since engine brakes create so much noise, they have been
outlawed in several mountain communities, and even at entrances to
toll booths on level-terrain highways. The use of engine brakes
has been severely curtailed. So even though they are effective,
they are annoying – and often illegal!
On the other hand, exhaust brakes are relatively
quiet. They build the back pressure required to retard the
vehicle’s momentum without producing all the clatter.
In the early 1990s this "big rig" technology
became available to pickup and motorhome owners.
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How does an exhaust brake do what it does?
In effect, an exhaust brakes turns the diesel engine into a big
compressor. In contrast to the gasoline engine which restricts air
intake, the exhaust brake restricts exhaust outflow to create
pressure. And with diesel engines creating 200+ horsepower,
regulating back pressure can provide powerful braking assistance
for the diesel owner.
On most downhill grades exhaust brakes engage
automatically to help slow the vehicle’s momentum. This permits
the diesel-powered pickup or motorhome to stop quicker. Exhaust
brakes also save wear and tear on the wheel brakes. Finally, and
most importantly, safety is increased and the butterflies in the
driver’s stomach go back to sleep and the driver is truly in
control of his rig.
U.S.
Gear offers exhaust brake alternatives
Cutting off air to a gasoline engine is not a problem. They are
designed to operate with a throttle body. Like human beings,
though, if diesels don’t get air, they die. Butterfly valves,
however, are the most effective way of blocking flow in the
vehicle’s systems. That’s why butterflies are used in exhaust
brakes "behind" the engine for diesels.
U.S. Gear offers two types of exhaust brakes –
both utilize butterfly valves to create back pressure.
The "Standard" Model
Like all other exhaust brakes, the "Standard" model D-Celerator
controls pressure using orifices (holes) in the butterfly. The
orifice is sized at the factory to keep your engine from
over-pressuring at extreme RPMs.
As you can see from the graph, the orifice (hole)
regulated "Standard" model builds maximum pressure at higher RPMs.
If you drive a small pickup or motorhome, and you rarely visit
mountain communities, then the "Standard" is the perfect solution
to help your vehicle perform up to its braking potential.
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The
"Super Duty" D-Celerator
U.S. Gear’s "Super Duty" model also uses a butterfly to create
back pressure. But unlike other exhaust brakes, the "Super Duty"
D-Celerator has a patented turbo-inspired waste gate to manipulate
the amount of pressure built up in the engine. This means that
when the butterfly is closed, it is 100% closed with no exhaust
leakage because there are no orifices (holes) in the butterfly.
Remember, the only reason for the orifices in other exhaust brakes
is to keep you from destroying your engine by creating excess
pressure at higher RPMs. Since the "Super Duty" model has a
waste-gate bypass, back pressure is bled off only when necessary.
The waste-gate valve spring is pre-set at the factory to open
only as often and as much as necessary to avoid damage to your
specific diesel engine.
Side View of D-Celerator® Showing Patented Waste-Gate Bypass
and Oversized "Open/Closed" Butterfly
Better performance at lower RPMs
The unique design of the "Super Duty" D-Celerator allows it to
build pressure very quickly at lower RPMs. Referring to the chart,
notice that because of the waste-gate you can receive the benefit
of maximum back pressure almost all the time without excess
pressure. And what is the benefit? – additional braking assistance
you can feel in the seat of your pants almost immediately after
the exhaust brake is engaged.
Since most diesel owners ideally run at 1,500 – 2,000 RPMs, the
"Super Duty" model is the clear winner in working with the engine
to provide maximum braking performance.
So if you sometimes tow heavy loads, or drive a large
motorhome, or often drive in hilly or mountainous areas, then the
"Super Duty" D-Celerator is for you. Even if those situations
don’t describe your driving patterns, you may decide to use the
"Super Duty" model simply to save wear and tear on your vehicle
brakes.
No matter what your situation, we have an exhaust brake to
meet your needs!
Why U.S. Gear?
U.S. Gear is proud to be the only manufacturer to offer two models
of exhaust brakes. The "Standard" model provides effective braking
assistance for light duty applications under non-strenuous
conditions. The patented "Super Duty" D-Celerator renders superior
braking support at both low and high RPMs, and also in extreme
environments such as heavy vehicles or loads and mountainous
regions.
The D-Celerator advantage includes the fact that both models
are the only computer-controlled exhaust brakes in the industry.
This gives U.S. Gear the freedom to add extra innovations such as
the outstanding "cycle feature." The cycle feature eliminates a
problem common to the exhaust brake industry. Specifically, the
cycle feature does away with the soot build-up from diesel exhaust
which causes the butterfly to bind, generally from lack of use.
In addition to their "self-maintenance" characteristics,
stainless steel components also extend the durability of the U.S.
Gear diesel exhaust brakes.
Because all D-Celerators are installed downstream in the
exhaust system where there is more space, U.S. Gear’s exhaust
brakes have an oversized casting. This means that since the
exhaust brake is not in use 95% of the time, the open butterfly
and pivot shaft don’t present a barrier to the swirl of diesel
exhaust gases exiting the turbo. In fact, the D-Celerators
actually improve flow by increasing the area available in the
exhaust stream.
D-Celerators are available in a wide variety of models ranging
from 2.5" to 4" and either air-activated or electric-activated.
U.S. Gear’s exhaust brakes are easy to install and are proudly
made in the USA.
To top it all off, the D-Celerators are accompanied by the best
warranty in the industry and both models have a 90 day customer
satisfaction guarantee.
Why look anywhere else?
U.S. Gear has more than 40 years of manufacturing experience and
is a recognized leader in the diesel and RV performance industry.
The family owned and managed company uses the most current of
today’s technology to build products with old-fashioned values –
like pride in workmanship and meeting the real needs of
customers.
Remember that regardless of your driving patterns, there is a
D-Celerator that is right for your diesel pickup or motorhome.
There will never be a better time than right now to enhance the
pleasure and safety of your driving experience.
Application
There's a D-Celerator available for all popular diesel tow
vehicles: Dodge, Ford, Chevy and GMC - trucks, vans, and class "A"
or "C" motor homes.
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