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 mechanically 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 carcass 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 45 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.