Did you know you can hire out our dyno? Private and commercial rates are available.
We operate the only hub dyno in commercial use in Scotland, the benefits of using a hub dyno over a traditional rolling road on high horsepower cars can be seen in this video of this MK2 Ford Focus tuned by Devil Developments producing 918 bhp/ 756 lbft at the hubs (~1000 bhp flywheel).
As you can see in this video, despite producing over 900 bhp at the hubs it looks as though it could only be producing 300 bhp.
THE FIRST AND MOST OBVIOUS DIFFERENCE IS THE ELIMINATION OF THE TIRE TO ROLLER INTERFACE ON A CONVENTIONAL ROLLER DYNO.
The Dynapack™ eliminates this variable by using a hub adaptor that provides a direct coupling to the Power Absorption Units. There can be no tire slip, no rolling resistance, and no chance of the vehicle coming off of the dyno at high speeds. Notice that we call this a variable. Sometimes it may be a problem area, other times it may not. Tyre temperature, pressure, traction, etc, are all variables that can change – not only from run to run, but during the run as well.
Throw an unknown variable like this into the equation and your data has now become subject to a potentially high margin of error. It is obviously better if these variables could be eliminated. There are other associated problems with the roller method as well. Take tie-down straps for example, most roller dyno’s use ratcheting tie-down straps to attempt to hold the vehicle in position while being tested. If the straps are cinched down tightly, the tire has become loaded even further, in an unpredictable manner.
While this may be good for enhancing traction, it changes the rolling resistance of the tire – skewing the data further. Since these tie-down straps aren’t perfect, the vehicle squirms around on the rollers – dramatically changing the tire drag during the run. If the vehicle is tested in two different sessions, the straps can’t be set exactly the same way twice in a row. Again, the data will be inconsistent.
We have heard of cases where the ratcheting tie-down straps were loosened by two clicks and the measured power increased by ten horsepower. What if the straps stretch – either from run to run, or during the run itself? Wouldn’t it be great if all of these problems could disappear? With a Dynapack™, they were never there in the first place.
ANOTHER MAJOR DIFFERENCE IS THE EFFECT OF INERTIA.
Street wheels and tires spinning at high RPM have a large amount of inertia. A large steel drum spinning at the same ground speed has much more inertia. What you end up with is a giant, heavy flywheel attached to your engine. The inertia is such that just trying to accelerate the mass of the roller is a substantial load for the engine. That is the principle that some roller dyno’s (or inertia dyno’s as they are also called) operate on. Accelerate a known mass to a measured speed over a given time and it can be calculated to equal a certain amount of power. There is nothing wrong with this theory, but like many theories, its application in the real world can be troublesome.
How do you think your measurements will be effected by being subjected to this large heavy flywheel phenomenon? Will small fluctuations be noticeable? In a word, no, the flywheel effect tends to take small rapid variations and smooth them right out – as energy that should be going into the dyno is being wasted trying to accelerate a large lump of steel. This is great if you want your power curve to look like a smooth pretty line, but it doesn’t give you much insight into what is really occurring. What if you eliminated this flywheel effect? The inertia of a Dynapack is practically zero!
THIS ALLOWS US TO PRECISELY MEASURE AND DISPLAY TINY RAPID PULSES AND ODDITIES THAT YOU MAY NOT HAVE SEEN BEFORE. NOW YOU HAVE A WINDOW INTO AREAS THAT NO ROLLER DYNO WILL ALLOW YOU TO SEE.
Another benefit of having virtually zero inertia is the ability to change the rate of acceleration at will. In many situations, you may want to accelerate the vehicle at a different rate to simulate a specific condition. With a few simple keystrokes, we allow you to make the vehicle accelerate very quickly, slowly, or anywhere in between.
THE DYNAPACK CONTROLS THE CAR
THE THEORY OF OPERATION AND THE IMPLEMENTATION OF THAT THEORY ARE ACTUALLY FAIRLY SIMPLE. IT TOOK SEVERAL YEARS AND A LOT OF HARD WORK HOWEVER TO MAKE OUR DYNO AS SIMPLE AS IT IS TODAY.
The hubs of the vehicle are directly attached to hydraulic pumps. We can apply a variable but precise load with all of the potential holding power that hydraulics possess. The wheels are removed from the vehicle. The variable fit hub adaptors are bolted to the vehicles axle. The hub adaptor is then directly attached to a hydraulic absorption unit. We can apply a variable but precise load to the axle of the vehicle.
Simultaneously, we are monitoring pressures and measuring hub RPM, so we can determine the amount of work being performed. It sounds easy until you realize that all of these calculations are very complex and are happening very quickly. Add to this, all of the data logging functions and real-time full-color graphics that are also being calculated and you begin to realize that what appears to be simple is actually very complex…being the best is never easy.
Traditionally, most serious engine builders have thought that chassis dynamometers were inferior to the results you could obtain from a quality engine dyno. We have effectively attached engine dyno style load cells to the axles, so we now have the type of precision and repeatability normally associated with an engine dyno, but with the convenience and benefit of having the engine operate in its natural environment – which has enabled many people to see better results than they were getting on their engine dyno.
Because we need a precise and powerful loading device, we use hydraulics. We do not use inertia, we do not use eddy currents, air, or friction. Because of the incredible holding power hydraulics offer, we have TOTAL control of the axle speed.
Want to hold a steady RPM under high power? We can hold an exact axle RPM (+/- one RPM) at any power level – all the way up to the full maximum rated torque capacity of the dyno (1350 hp, 1036 kW, 3319 lb/ft, 4500 Nm), CONTINUOUSLY – for as long as you like. If the software allowed it, we could stop the engine within one revolution of the axle – even if the engine is at full throttle at its maximum torque level. Obviously you would not want to do this, and the software prevents it, but it does give you an idea of just how much power and control we have over the axle speed.
The Dynapack controls the car, We control the axle speed and rate of acceleration at all times, it allows you to see exactly what the vehicle is doing at any given point in time and RPM of the completed run. Because we aren’t limited by the capabilities of eddy current brakes and similar devices, we open up a whole new world of tuning possibilities.
FEATURES AND BENEFITS
Ease of use: The Dynapack™ uses Windows based software and so it’s instantly recognisable and friendly.
Fast set-up time: Two people can take a Dynapack™ out and have a vehicle testing on it in less than 10 minutes.
One of the biggest assets of the Dynapack™ system is its ability to conduct multiple runs back to back and provide amazing levels of repeat-ability.
The lack of inertia in the Dynapack™ system allows the sensitivity to be greatly improved over traditional dynamometers. We can reliably measure minute differences.
An example of Dynapack’s testing includes a .010″ change in a spark plug gap!
Many world class OEM manufacturers as well as tuning houses rely on the Dynapack™ and its amazing sensitivity to develop their products.
That’s right PORTABILITY because of the design of the Dynapack™ it is portable and the possibilities are endless.
Need us to come to your place of business?
Need us to take the dyno to the vehicle or to the track?
The Dynapack™ is ideal for track-side tuning, fault finding and testing/parity. Dynapack™ is used around the world at race tracks using a small 1000 watt portable generator.
Our dyno at speed measures around 60 to 80dB depending on load – much quieter than the engine at idle. This is especially beneficial if you want to perform NVH (Noise Vibration & Harshness) tests or audio recording. Dynapack dynamometers™ are already in use in NVH labs. You will find that you can now use your ears as an additional diagnostic tool, since all you will be hearing is the vehicle.