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Frequently Asked Questions
on
DYNOmite
Dynamometers
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Listed below are the questions (and their
answers) that we are most frequently asked with regards to dynamometer
selection, set-up, and operation. If you would like more information about our
DYNOmite engine dynamometers and chassis dynos, just give us a call. A technician will be glad to try and answer your
questions.
"You can e-mail your
questions and or sample test data too! "
HOW MUCH SHAFT HP CAN I DYNO?
Any Hp engine can be measured with the correct equipment! If
you will be using an absorber it
needs to be mechanicaly rated for the engine's
expected peak torque.
Water brake absorbers dissipate the
engine's Hp as waste heat
energy - via their hot water discharge.
(Figure about pumping 1 gallon per minute minimum through the system for every 20 Hp
you are able to produce.)
Air cooled eddy current absorbers get rid of the Hp
through ventilated rotors (like disk brake rotors) and have load charts that
show both their initial COLD and 20 minute HOT Hp dissipation capabilities.
Rotary Strain Gauge Transducers measure the shaft's torque
with the engine in service. Since they are applied to the standard driveline,
they can be used to measure up to any Hp level! If your driveline can take it,
the DYNOmite can measure it!
Inertia "dynos" don't provide a Hp dissipating
load, rather they use a computer to calculate the energy used to accelerate a
known mass. While more limited in what they are good for, they are only limited
by traction and/or RPM safety limits in terms of Hp capacity.
HOW MUCH WHEEL HP CAN I HANDLE ON A CHASSIS DYNO?
Chassis dyno Hp limits come from two main areas -- traction
and absorber capacity.
The diameter of the rollers affects the tire contact patch
area which in turn affects traction and tire deformation. Rollers less than
about 33% of tire diameter should be avoided as they will damage the tire's caucus
under sustained high speed/high Hp running. Capacity improves significantly as
roller diameter is increased towards the tire's diameter. Beyond that point
there is only a marginal improvement in Hp capacity.
Knurled or grooved rollers are also necessary to get any real
Hp capacity as the friction between smooth steel and rubber is quite low. The
DYNOmite rollers all feature a special deep straight pattern to avoid the tire
damage that heavy diamond pattern knurls or groves can cause.
Even if you can put the power to the rollers, you will need enough
absorber capacity to handle the expected power. See the question above about
"HOW MUCH SHAFT HP CAN I DYNO" for more information on this
subject.
HOW MUCH WATER WILL MY ABSORBER NEED?
Water brake absorbers get rid of the Hp energy as waste heat.
Assuming you start with water at 60 degrees and must maintain a discharge temperature
safely below the boiling point, Figure about pumping 1 gallon per minute through
the system for every 20 Hp you are able to produce. Thus a 1,000 Hp engine will
need at least 50 GPM to load the engine. In order to get this much water
through the restrictions of the absorber's load control and plumbing fittings
you will typically need to deliver the water at a sustained pressure of at least
40 PSI. Most lawn sprinkler type pumps are sell suited to this application.
If you run from a high capacity well, municipal supply, or
clean pond and can directly discharge the clean hot water into a drain then you
are all set. If you must run from a tank it should have large enough capacity
that it does not heat up more than about 20 degrees during your longest test
session. You will have to size capacity and/or heat exchangers based on your
testing duty cycle (run time vs. cool down time.) A kart engine builder may get
by with a simple 5 gallon pail. However 400 Hp will raise the temperature of 400
gallons of water by 150 degrees Fahrenheit in just 30 minutes. (In such a case,
a simple truck radiator and electric fan can be arranged into your sump drain
line to cool the discharge water before returning it to your tank.)
CAN I DO SWEEP AND STEP RPM TESTING?
Even when using manual load control our most basic DYNOmite
data-acquisition computer has software built in that can sort and filter the
collected data into an even 100 RPM sweep test format. Also, if you need
more advanced acceleration, step 'n hold, life cycle, engine break-in, race
track simulation, etc. testing you can add these capabilities at any time with
our automated electronic load control and DYNO-MAX software options.
DO I NEED TRAINING TO FIGURE OUT THE DYNO?
Most engine builders prefer to first install the system and
get familiar with the basics, planning to come for training after they have that
down. However, once they do that most realize that the simple user interface of
the basic DYNOmite and the DYNO-MAX help screens and Tutorial CD are all they
need. Whether you visit for training or not,
we still provide you with the best
personalized phone and e-mail technical support in the
industry!
DO I NEED A DEDICATED DYNO TEST CELL?
Many DYNOmite dynamometers can be operated outside of a
typical dedicated testing cell. For example the 800 Hp automotive engine dyno
test stand with the integrated wall console can be configured to run in a shop's
parking lot. You just need an adequate water supply to go. In fact, many snowmobilers and kart racers take their DYNOmites to the track with them. This
allows on-site tuning without eating up valuable "track time". Others
sell dyno time to other racers for profit or for free to build a larger customer
base!
HOW DOES THE AUTO ENGINE STAND DYNOMITE COUPLE MY ENGINE TO
THE ABSORBER?
The stand's Bell Housing Adapter Plate bolts to your engine's
stock or aftermarket manual transmission bell housing. The plate includes bolt
patterns for the most popular combinations (you can even drill it for most other
patterns.) A splined alloy steel input shaft fits into a standard clutch disk,
or dyno drive plate. This design eliminates power absorbing u-joints, and
driveshaft alignment requirements. It also means none of the engine's torque is
transmitted through the dyno frame!
CAN I BUILD A "TRAILERABLE" DYNO CELL?
Yes, the whole design of the DYNOmite is so tuned to portability
that it is probably the easiest dyno in the world to mount in or on
a trailer. See the questions on "DO I NEED A DEDICATED DYNO TEST CELL?"
and "HOW MUCH WATER WILL MY ABSORBER NEED?" for more
information.
WHAT IS THE WARRANTY ON A DYNOMITE DYNAMOMETER?
See "Warranty - DYNOmite Dynamometers"
for more information.
HOW LONG HAVE YOU BEEN BUILDING DYNAMOMETERS?
Land & Sea, Inc. has been building custom dynamometers for over 25 years, and computerized systems for more than 20 years
(well before the IBM PC)!
Today we manufacture the most complete line of engine
dynamometers, rolling road chassis dynos, and digital wireless rotary strain
gauges in the world. We don't just assemble components either, we CNC machine
each absorber, dynamically balance rotors, weld every frame, turn our 4'
diameter rollers, assemble our eddy current control boards, and write our
DYNO-MAX software in-house! We entered
our 32nd
year as the
fastest growing dynamometer manufacturer in the United States.
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