America's #1 Snowmobile Newsmagazine
JANUARY/FEBRUARY 1993 VOL. 7, NO. 5 SECTION A
The portable Land & Sea developed snowmobile dyno is so simple to operate that even our editor can do it!
Text & Photos
by Jerry Bassett
Land & Sea is one of those off the beaten track shops that is based on brain power and marketing savvy. President Bob Bergeron supplies the brain power for creating new products and Chief Executive Officer Bob MacDonald adds marketing and business
acumen. Combined the two have kept Land & Sea in a growth mode despite the fact that its Southern New Hampshire business neighbors have fallen on extremely hard times.
Bob MacDonald wouldn't claim to be an astute businessman a few years ago. As he told American Snowmobiler, he bought into Land & Sea at a time when the marine industry was going into the dumper and the general East Coast business climate was taking a nose dive to bad times. He admits, that as an enterprising businessman, he was having his doubts.
You see, until about a year ago, the marine industry was Land & Sea's key market. With a product line that includes essential gear for performance boaters like the popular Hydro-Electric Transom™, high performance reeds for boat engines and a variety of other products, Land & Sea was dependent on summer boating for profitability. Yes, the company's unique Torque-Shift automatic shifting marine propeller is a stalwart product. It shifts from low pitch to high pitch and Land & Sea is the only firm to offer such an item.
Still, MacDonald felt that a good contra-seasonal product would help his business and help him to sleep better at night.
Enter the brain of Bob Bergeron. The man who invented the Torque-Shift prop just happened to be a snowmobiler as well. (In fact, if you thought you had a good job, you should tour the Land & Sea back rooms. They have all the toys! Go-Karts, snowmobiles, Jet Skis, motorboats, motorcycles, etc. And it's all legit!)
In coming up with a new product, the two Bobs thought about creating something that would be unique, have a narrow field of competitors, and have value to its customers. Bob Bergeron thought about his snowmobiling experience. A product in snowmobiling would make sense; it could add profitability in a normally lean period - not many snow country boaters get excited about launching their bass boats in January.
Since the firm has experience with engines, their testing and performance, they thought about performance products, like reeds, aftermarket hop up kits, etc. But, there's a lot of competition in that market. Then, they thought about what racers and dealers might need. Racers would like to know how well their sled's engine is performing, but how do they find out? They can field test it. They can take a trip to a dyno. Too bad they couldn't field test their sled engine on a portable dyno?
That's all Bob Bergeron needed. Why not, indeed! Dynamometers are essentially all the same. They are engine brakes from which you read torque. Once you have a few basic facts, you can deduce a number of things, like horsepower. And, if the dyno unit were portable, it could take "real world" readings. Perhaps it could fit on the sled?
It sounds rather incredible, but once Bergeron arrived at what he wanted to do, it was a matter of implementing the action. The dyno would have to be compact, but able to withstand the torque of a twostroke snowmobile engine. Like a $100,000 Superflow or a traditional Henke or Stuska dyno, the Bergeron-designed DYNOmite portable dynamometer lab basically functions in the same manner. They all use a water brake to load an engine and have an arm or some device to register and transmit readable torque.
Thanks to today's quest for smaller and more powerful computers, Bergeron was able to incorporate modem technology with basic science and create the DYNOmite portable snowmobile dyno. It's incredibly simple, wonderfully user friendly, and relatively inexpensive at just $2,995. It's also a very well done piece of equipment. Carefully machined at Land & Sea, the DYNOmite has the look of fine craftsmanship in its pieces.
When we toured Land & Sea this past December, MacDonald and Bergeron gave us the tour. They showed us how the pieces are machined, pieced together, and the finished dyno calibrated to the specific computer for each individual DYNOmite.
If you can program a digital watch, you can run a DYNOmite. Trust me. Even I was able to dyno a sled. Of course, practice makes perfect and we would recommend that you learn and practice your technique on a strong engine.
Land & Sea knew that we were coming. They had set up a DYNOmite on a modified Polaris triple. First Bob Bergeron walked me through it. Then I watched Land & Sea sales manager Peter Schroeder make a run.
It was my turn. Bob Bergeron suggested that I'd probably feel as though I had two left feet on my first try. I figured he'd be right. Hey, he should know. He invented the thing.
Surprise, I did okay. In fact I liked it. This thing was a hoot to operate. You squeeze the throttle, screw in load, watch the tach and listen to the engine. When it starts to be overcome by the load, back off and let it stall out or shut it off.
The DYNOmite comes in a black case with all the items - except a snowmobile - you'll need to be a dyno technician. Key components are the dyno "water brake" and computer. The little handheld computer can read up to 200 data points a second. If you purchase the optional printer, you can get a printout of all the salient information during your dyno run.
So, how does this thing work? You place your order for a DYNOmite. A while later it shows up encased in a black plastic carrying case. Inside is the "water brake" with attached torque arm, the computer unit, a handlebar-mounted water pressure valve to control water flow to the "brake" and some basic hoses. Inside the red "dynomite" labeled dyno is a machined impeller that helps the motor turn the water from a garden hose into hot water. As Bergeron says, all a dyno does is make hot water. The water pressure valve helps you control the water flow and places "load" on the engine. It's this valve that you screw in and out to affect pressure on the torque arm.
Okay, so you've got all this stuff. You remove the clutches from your sled. While placing the DYNOmite on the engine's driveshaft, you slip the DYNOmite’s torque arm over the secondary shaft. Thus keeps the arm from turning. Then you mount the load pressure valve on the handlebars by clamping it on the left handle grip. Hook up the vent hoses to the DYNOmite and attach a garden hose to the load pressure valve's inlet.
You'll need to splice a few wires to hook up the engine to dyno wiring harness which came in the black box. Normally you'll be hooking into a good ground, the sled's kill switch system, and the AC output of the engine's alternator. The computer counts the pulses to determine engine rpm. Land & Sea includes a number of terminal adapters so you can quickly plug into the same sled time and tune again, simply and easily.
Now you've got it hooked up. What's going to happen and how does this thing work? Basically horsepower is equal to revolutions per minute times torque divided by 5,252. That's the formula the computer uses to deliver data. The DYNOmite provides both a way to load an engine (the water brake) and to monitor rpm and torque. The digital tachometer monitors rpm. The electronic strain gauge monitors torque. The computer does the calculations at 200 readings per second.
The DYNOmite’s water brake draws water from the pressure regulated garden hose and pumps it through the re-circulating vanes of the internal impeller. Engine horsepower, normally used to power the sled through snow, is redirected to generating heat by pumping and re-pumping the water inside the water brake assembly. The force created by the internal impeller pumping water against the external housing creates a rotational force which can be read via the torque arm secured to the secondary clutch shaft. An electronic strain gauge reads the bending action of the torque arm in a digital foot-pound display.
Here's where computerization kicks in big time. The computer reads the data, makes the calculations and displays it in sustainable power figures.
Because the dyno is mounted on the sled and operations would be normally performed outdoors, the readings may be lower than a perfect "in house" dyno might show for an engine mounted out of the sled in a dyno room. What you get is a measurable indication of your engine in its normal setting. As any veteran snowmobile racer knows, temperature, humidity, and barometric pressure can make differences in power on the same engine in the same day.
This does not matter if you are doing back-to-back reading for evaluation of a modification; but if you want to compare readings now with ones taken under different atmospheric conditions, then you should be calculating corrected horsepower. You can make these corrections manually, or you can enter the temperature, humidity and pressure in the DYNOmite’s computer and it will do the corrections for you. You can then select whether to print out corrected or uncorrected data, or both.
To protect your engine, the computer can be set to over ride the sled's engine and "kill" it if it tries to rev over a set rpm.
What you'll normally see on the printout will be rpm, torque, horsepower, the duration of the dyno run and the number of readings taken at each point. As of our visit to Land & Sea, the DYNOmite computer software was already on Version 20. Software updates are available as they come along. Land & Sea is constantly working to keep the DYNOmite up to date and able to satisfy consumer needs. That's why the software updates have continued.
As customers develop new needs for the dyno, Land & Sea seeks to service them.
The DYNOmite is a unique piece of equipment for snowmobilers. It doesn't have the bells and whistles of a $100,00 Superflow dyno, but for $97,000 less, it does about the same things. And that's quite a statement! And savings!For more information about the DYNOmite, contact: Land & Sea, 25 Henniker Street, Concord New Hampshire 03301 (Telephone, 603/226-DYNO; Fax, 603/226-4FAX).