Dynapack™ chassis dynamometers are such a radical departure from the stereotypical roller dyno that it really is in a class of its own.
Most of the previous assumptions made about traditional dynamometers simply do not apply to the Dynapack™ series. In fact, you will discover that we give you tools and capabilities that have previously been thought impossible to achieve on a chassis dyno.
Dynapack™ allows you to quickly and accurately measure engine, drive line and other performance data, with previously unseen sensitivity.
Dynapack™ attaches directly to the axle(s), thereby overcoming all the disadvantages of tyre distortion including noise, torque steer, loss of traction, tyre heat and design variations in the tyre.
• Precise engine results – no inertia to mask faults
• Repeatable – accurate back to back runs within 0.3%
• Portability – on and off site
• Stress free – 2 to 30 sec. runs for all data types.
• Minimal noise level – no tyre interface
• Virtually no installation and running costs
• Cost effective – chassis and engine dyno capable
• Flexible, easy to use software
How is it different?
The first and most obvious difference is the elimination of the tyre to roller interface on a traditional roller dyno.
The Dynapack™ eliminates this variable by using a variable fit hub adapter that provides direct coupling to our power absorption units. There can be no tyre slip, no rolling resistance, and no chance of the vehicle seperating from the dynamometer at high speeds. Notice that we call this a variable. Tyre temperature, tyre pressure, tyre 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 potetially high margin of error. It is obviously better if this can be eliminated – which is what we have done. What you end up with a traditional roller design 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.
Will your measurements be affected by being subjected to this large heavy flywheel phenomenon? And will small fluctuations in power delivery be easily noticeable?
In a word, no. The flywheel effect tends to take small rapid fluctuations and smooth them right out. 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 the flywheel effect? Whilst every spinning mass has some inertia, when compared to the total mass of the wheels, tyres, rollers, and other associated hardware in a traditional roller dyno, the inertia in the Dynapack™ is practically zero.
This allows us to precisely measure and display tiny rapid pulses and oddities that you may not have ever seen otherwise. Another benefit of having virtually zero inertia is the ability to change the rate of acceleration at will. In many simulations, you may want to make the vehicle accelerate at a different rate to simulate a specific condition.
With a few simple keystrokes, we can allow the vehicle to accelerate very quickly, very slowly, or anywhere you’d like in between.
Because of the lack of inertia and the total control we have over the axle speed, we give you choices. And as you know, choices are good!
This makes Dynapack™ an outstanding choice in chassis dynamometers whilst establishing a new industry standard.
How it works
We use hydraulics. We do not use inertia, we do not use air, we do not use eddy currents, and we do not use friction. Hydraulics are incredibly powerful, yet precise.
We have complete control of the axle. Want to hold a steady RPM? We can hold an axle RPM (within 3 rpm) for a stable engine at any power level – all the way up to the rated maximum torque capacity of the dyno for as long a period of time as you’d like. Such is the level of control, if the software allowed it, we could stop the engine within one revolution of the crankshaft.
The wheels are removed from the vehicle. Our 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(s) of the vehicle. Simultaneously we monitor load and measure hub RPM, from this we can
determine the amount of work being performed. It sounds easy until you realise that all of these calculations are very complex and are happening very quickly.
Add to this, all of the data logging functions (every single engine RPM) and real-time full-color graphics that are also being calculated, and you begin to realise that what appears to be simple is actually very complex.