How to Select the Proper Performance Engine Dyno

Water Brake Absorbers

Water brake dynamometers use a hydraulic brake that converts the energy produced by the engine into heat transferred to the water flowing through the dynamometer. There is a stationary side (stator) and a spinning side (rotor) each with cup shaped pockets that transfer water from one side to the other. An automatic control valve bolted to the dynamometer controls the amount of water in the dynamometer based on the test requirements to produce the required load against the engine.

The major advantage of water brake absorbers is that they offer a wide dynamic range meaning one dynamometer can test a wide range of engine speeds and engine torques – the SF-902S dynamometer for example is rated for 15,000 rpm and up to 1,250 lb.ft of torque, however it can also easily test small single cylinder engines that make less than 40 lb.ft. of torque. Water brake dynamometers are also the most economical type of absorber for dynamic testing making them great for a wide range of applications from testing internal combustion engines to electric motors.

Eddy Current (EC) Absorbers

Eddy current dynamometers use an electro-magnetic brake to load an engine. A rotor spins inside a magnetic field created by energizing a stationary coil. The spinning section creates resistance to the magnetic field thus applying load to the engine. This process turns energy from the engine into heat in the rotor which is dissipated by cooling water flowing through the absorber.

The major advantage of water cooled eddy current engine dynos is their precise and rapid load control. Varying the energy supplied to the coil can adjust the load from zero to 100% in a few milliseconds and the adjustment can also be very precise. The drawback to eddy current dynamometers is they are typically 40-60% more expensive than a water brake dynamometer and their dynamic range is narrower as well. This means eddy current dynamometers are typically selected for more specialized testing.

Alternating Current (AC) Absorbers

Alternating current (AC) dynamometers use an electric motor to load an engine. When configured with a regenerative drive the energy the motor absorbs can be converted into electrical energy and returned to the power grid, reducing the cost of testing over time. AC dynamometers offer both excellent steady state and transient control. An additional benefit of AC dynamometers is, in addition to loading an engine, they can also motor an engine to simulate the inertia of a vehicle motoring the engine down a hill or performing tightly controlled transient simulations like those required in a government mandated emissions drive cycles.

Selecting the Type of Absorber

With an understanding of how each type of dynamometer creates load and some of their advantages for different types of testing we can discuss the remaining factors we need to understand to select the proper absorber.

RPM and Torque – It is always helpful to have a torque curve of the engines you want to test – comparing engine torque to dynamometer torque across the speed range allows us to quickly determine the available absorbers for a project. Sometimes the complete torque curve isn’t available – at a minimum we need to know peak torque and the RPM it occurs at as well as the speed range the absorber will need to accommodate. We recommend a 15 to 20% safety margin (depending on the type of absorber) between the dynamometers torque curve and the engines torque curve to allow the dynamometers control system room to maintain control of the engine and for instances where some engines inevitably make more power than expected.

Control Tolerances – Modern electronics have advanced the control tolerances available to water brake dynamometers a long way in recent years. SuperFlow’s dual valve control system found on the SF-Powermark dyno can produce steady state control of +/- 10-20 RPM and it also allows us flexibility to use different control strategies to choose the best one for a given application. Both eddy current and AC dynamometers will have much tighter control in both steady state and transient testing than a water brake dynamometer – here we could expect +/- 2 RPM or better depending on the prime mover.

Test Requirements – All three types of absorbers can perform steady state, step, sweep and transient test profiles. SuperFlow’s WinDyn Data Acquisition and Control System allows users to select the desired profile, input parameters for starting and ending points and ramp or step times and then execute the test. Additionally, track lap data, emissions drive cycles and other transient profiles can be input into the software and run on the dynamometer. Again, only the AC dynamometers are capable of motoring an engine for inertia simulation so any requirement for a drive cycle of other emissions test profile would require an AC system.

Contact Us for System Prices

Combining the overall application requirements for speed, torque, control, and test requirements leads us to the correct power absorber and dynamometer system. Our sales engineers are trained to listen to the application, ask questions when needed and help you select the proper equipment for an economical solution for your project. If you have an engine testing need you’d like to inquire about call us at (262) 252-4301 or contact us online.

Chassis Dyno Installation

CChassis dyno installation can be a headache for first-time users, and it requires a lot of preparation on behalf of your truck service center. Luckily, Power Test’s industry-leading facilities team and representatives are available to work with you every step of the way. Our DCI team, which has over 30 years experience in the design, construction, and installation of dynamometer test cells, is available to provide you with everything necessary for a state of the art facility and will manage the project to completion. Many facilities, though, are fully capable of constructing their own test center with minimal direction from Power Test.

Whichever category you may fall in, there are a few initial considerations you should make when prepping for your install. These tips, available for download, are specific to the testing industry and will benefit even the most experienced facilities experts.

Please enter your name & email for a free download of your Eddy Current Chassis Dyno Installation checklist.

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Army Physical Fitness Test

A Healthy Lifestyle

One of the core values here at Power Test is “Ski with your grandkids when you’re 77.” While it may not be obvious at face value, every one of our employees can tell you exactly what it means. It’s the representation of our commitment to a physical fitness and a healthy lifestyle.

All year long, Power Test offers it’s employees opportunities to pursue healthy lifestyle choices. Five nights a week, we bring a personal trainer into the facility to give a group class in our state of the art workout room. The classes are scaled so every person at any age can enjoy a challenging and invigorating workout. In addition to the workout classes, we also offer lunch seminars each month that focus on making healthy decisions in the kitchen. Nutritionists visit with employees during their lunch hour and discuss a wide range of nutrition topics that are applicable to busy professionals.  Participation in the workouts and the seminars are incentivized through our healthcare provider, as well as through a monthly monetary contribution from Power Test.

Physical Fitness TestBut the biggest incentive towards a healthy lifestyle comes twice a year in the form of the Army Physical Fitness Test. In early spring and late fall, all employees are given the opportunity to perform the Army PFT on a Friday afternoon during the workday. Military personnel from local armed forces affiliate are onsite to administer the test and help to maintain a supportive, but competitive environment.

Physical Fitness Test Standards

The test is comprised of three different parts. First, there is a 2 minute push-up test where participants attempt to complete as many reps as possible. Immediately following the push-ups is a 2 minute sit-up test. After those are complete, the entire group heads outside to run our 2-mile course as fast as possible. If they complete the required exercises at a 60 percentile clip, they will qualify for a bonus of up to $1000.  This bonus is intended to be used as an HSA stipend, a gym membership, or in the pursuit of other healthy activities, but ultimately employees can do with it what they like.Physical Fitness standards

On Friday November 4th, 42 Power Test employees participated in the event and combined to earn over $25,000. Power Test is especially proud on days like this to see our employees living our core values. The atmosphere of teamwork, encouragement, and support carries through long after the workout is over and truly makes Power Test a special place to work.

Where You Can Find Us – July 2016

Power Test Plan – July 2016
Every month, Power Test Sales and Service professionals travel the globe making sure our customer’s needs are met.  We believe that on-site, personal interactions with our customers is key to Making It Better.  By consulting with you directly, we hear firsthand of the challenges and opportunities you’re presented with.  Our team of highly knowledgeable reps work with you to explore every possible solution to all of your testing needs.

This July we have a number of international travel destinations already scheduled, with more to be confirmed as the month moves on.  As always, reach out to us if you see that we’ll be in your area, or let us know if you’d like to schedule a visit.  Each of our sales and service team members makes it a priority to visit customers on a monthly basis, and we’re always looking for an excuse to come visit you.


International Visit Locations:

Mexico City and Guadalajara, Mexico
July 17th – July 30th

David Lanser will be visiting Mexico towards the end of the month to meet with existing and potential customers.  Reach out to David if you’d like to schedule a visit, or hear more about the regions that he serves.


South Korea  |  Japan
End of July

Rick Ballo will be traveling to South Korea and Japan in July to consult on an active project, but has made some time to schedule visits with customers and partners.  Let Rick know if you’d like him to stop by.


The rest of our sales team has some specific appointment dates set up for the month of July, and always has time to schedule more.  Visit our Contact Us page to set up an appointment or to get in touch with us with any questions you may have about your testing needs.

Where Will We Be? – International Travel Calendar

International Travel ImageHere at Power Test, We Make It Better for our customers.  That’s why our sales and service representatives travel the globe visiting with you, our customers, to make sure that Power Test is doing everything it can to support your business. This month is no different as we have representatives visiting a number of domestic and international locations.  Take a look below at where they’ll be, and give them a call to schedule a visit.


International Visit Locations:

Saudi Arabia; United Arab Emirates
June 5th-9th

Rick Ballo will be visiting existing clients in the region, but has set aside some time to meet with anyone interested in learning more about Power Test Dynamometers.  If you miss him this time, reach out and let him know you’d like him to visit in the future.

Toronto; Montreal, Canada
June 13th

Dan Jens will be meeting with customers in eastern Canada.  Dan is the regional sales manager for the eastern United States and Canada and has made himself available for visits throughout the summer.  If there’s something you’d like to meet with him about, feel free to reach out to put something on the calendar.

Paris, France
June 13th-17th

Mark Wellman and Rob Kazmier will represent Power Test at the annual Eurosatory Defence & Security International Exhibition in Paris.  If you happen to be in attendance, stop by Booth CB517 for a visit to learn more about Power Test’s Military focused products.  If you can’t make it, but are in the region, reach out to Mark or Rob and schedule a visit.

Calgary; Edmonton; British Columbia, Canada
June 20th-22nd

Pat Koppa and Wayne Mohler will be visiting a number of cities in western Canada.  There’s plenty of time to schedule a visit if you’d like them to stop by.

End of the month

David Lanser will traveling to Mexico towards the end of the month and is always looking for opportunities to engage with our customers.  Schedule a visit with him this June, or let him know that you’d like to meet with him another time.

Power Test in the Community – April 2016

Power Test in the Community

At Power Test, ‘We Make It Better’ in all that we do. We make exceptional products and provide unsurpassed support. But equally as importantly, we believe in building up our employees and our community. Take a look at what we’ve done in April to make that a reality.


Waukesha County Technical College opens new Integrated Manufacturing Center:

WCTC representatives and dignitaries officially cut the ribbon at the grand opening for the WCTC Integrated Manufacturing Center Monday, April 5, 2016.

WCTC representatives and dignitaries officially cut the ribbon at the grand opening for the WCTC Integrated Manufacturing Center Monday, April 5, 2016.

The doors to WCTC’s new Integrated Manufacturing Center opened on April 4th. Power Test was happy to do their part in making the two-story, 24,000 square foot a reality. The IMC more than doubles the lab and classroom space dedicated to manufacturing training at WCTC and is a significant step forward in the education of skilled workers in Wisconsin.


Generations Against Bullying:

In April, Power Test showed its support for ‘Generations Against Bullying’ to bring awareness to the effects of bullying in our communities. Join Power Test in supporting their mission by taking a look at the wonderful work they’re doing.

Power Test hosts Schools2Skills Program:

Students Visit Power Test

Students from Menomonee Falls High School visit the Power Test facilities as part of the Schools2Skills program.

In the final stop of the 2016 school year, students from Menomonee Falls High School visited Power Test as part of the School2Skills program. In their 5th year, Schools2Skills continues to take students into the area’s leading companies to learn more about manufacturing career paths.


Employee Nutrition Program:

As part of Power Test’s continued effort to improve the well-being of our employees, we’ve implemented monthly workshops with a certified nutritionist. With a focus on finding foods and lifestyle choices that encourage good health, mental stimulation, and productivity our employees are empowered to make positive changes in their eating habits.