DTec Home

 
Inertia & Brake Dyno (Dynamometer) Features - RC, Kart, Bike & Car - Engine & Chassis

 

 

Home DTec Products Gallery Tech Articles Downloads Links Purchasing / Terms Company Profile Contact

 

Dyno (Dynamometer) System Features

 

Overview

 

Suitable for chassis and engine dyno designs, either direct or indirect drive to the inertia flywheel. Power measurement can also be taken from a ‘load cell’ for use on brake style dynos (e.g. water, eddy current, hydraulic, friction). As standard DYNertia3 does not control the actual load on a brake dyno, the load must be controlled manually (i.e. it’s not closed loop). Please see the product page for details of optional upgrades to automatically control throttle and load devices.

Software provided handles all data management, analyzing and graphing required for your dyno project with powerful features yet a ‘clean’ interface. Both Metric and Imperial modes are provided, Power, torque and setup parameters are changed from kph/Kw/Nm/ºC to mph/Hp/Ft Lb/ ºF etc.

Comprehensive Manual provided, also design & construction information is available for the mechanical dyno system, including an Excel spread sheet (and imbedded tools) to assist with choosing and calculating the moment of inertia for your requirements.

Included magnetic sensor (hall effect) has an indicator for diagnostics. Integrated ‘optical isolation’ circuitry in the data acquisition systems helps limit ignition interference and provides PC protection.

Accuracy only limited by mechanical system variation, internally each rotation is timed to 1μs (1 millionth of a second). Dual microprocessors share the data acquisition and precision timing tasks.

Ideal for portable applications (track days & exhibitions). Power supply can be from a simple 12V battery, 7 to 18V DC is required, eg a cordless drill or bike battery is ideal!  We recommend a battery as resistance to interference and data acquisition signals is far better than with a ‘plug pack’!

Compact, approximately 110L x 83W x 45H (mm) with a small remote sensor for easy adaptation to your design.

No ignition system adapters needed for RPM reading. Can determine engine RPM from flywheel RPM by ‘learning’ their relationship (ratio). Up to 8 gears can be learnt and later selected for quick testing in any gear; the ratio can also be manually entered if no tachometer, simply based on number of sprocket teeth (e.g. for chain drive kart engine dynos).

If an engine RPM input (not otherwise required) from the engine is available, then this can not only be used as engine RPM but also means the difference between engine and flywheel RPM can be plotted to show clutch engagement RPM or reveal wheel slip on a chassis dyno.

Inertia value for up to 3 flywheels can be stored and easily selected for designs with adjustable Inertia mass to tailor to engine characteristics.

Compensation for Dyno Inertia during ‘brake’ testing is easily applied. Great if you have an inertia dyno, but add an additional brake (absorber) for ‘running in’ engines or ‘steady state’ testing.

5 analogue data channels and one digital input (secondary RPM input) are available to be displayed and recorded; these are completely flexible and can be used for input sensors such as air fuel ratio, exhaust temperature, pressure, load cell, secondary RPM. 2 ‘Math’s’ channels can be additionally be generated from any of the existing data (freely write your own formula to apply), just think of the tuning possibilities!

Updates to the basic DYNertia3 software will be available FREE as we continually seek to improve our product.

Analysing Test Results

 

Supports multiple monitors, if a second monitor is available then key screens can be viewed separately to allow clear analysis, even if viewing and comparing many test results.

Overlay up to 10 power and torque graphs simultaneously, including the ‘last run’ which automatically appears after your run is completed. Trace color sets are user selectable, however ‘last run’ always graphed in red for quick identification.

Analyse and compare test results by easily ‘hiding’ any particular trace or quickly replacing with other saved runs for comparison.

A reference trace can be locked so that it always stays on the screen for comparisons against other tests.

Up to 4 sets of runs can be merged to create a brand new 'averaged' run. Perfect for getting the most from analysis. The new generated file appears just like any other in DYNertia3. Comments are automatically attached that reveal the individual runs that it was generated from for future reference. 

All 5 analogue channels are recorded with each run for analysis and their value at the cursor are shown in a floating 'data box' (which can also be saved to ‘clipboard’). DYNertia3 can overlay 2 chosen data channels with the existing power and torque traces for display or all of the data for any trace can be shown in a separate single screen for detailed analysis.

Select a graph trace; an onscreen cursor makes the dials (power, torque and RPM/speed) display exactly what was happening at that point in the run.

Advanced torque analysis is provided to graphically display ‘area under the curve’ and related statistics for comparing multiple traces.

The percentage difference between a reference trace and the remaining traces can be shown graphically, for all data. Instantly see where each modification either improves or degrades performance compared to other runs.  Great tool!

Lambda / AFR deviation is shown in a special screen that allows you to set a target value, it shows you where and by how much the real test results varied (essential for quick mixture tuning). Obviously an AFR meter must be connected!

Select any RPM/speed points and the time between them is shown for all runs (up to 10), clearly reveals ‘real world’ acceleration improvements after modifications. Best performing runs between all points are highlighted.

Full data table display of ‘point by point’ power, torque, RPM and speed are produced for detailed study and can be exported directly into Microsoft Excel (with field headings included) or a text file (comma delimited ASCII, CSV.) can be generated, even the main graph view can be exported as a bitmap image (‘.bmp’) for further analysis and file sharing.

The relationship between distance traveled, time elapsed, speed and RPM can be studied in a graphical analysis screen.

XY graph, choose any data to plot against another and display values at the cursor.

Math’s ‘Expressions’ (formula) can be applied to any existing data to generate an additional 2 data channels. A powerful tool is provided to easily write, test and apply your concepts.

Click on the run of interest to show all the data that relates to it. The test conditions, max readings, set up details or any of your personal notes that are saved along with each run can all be reviewed.

Full manual ‘zoom’ available on Power, Torque and RPM displays to display selected graph regions of interest.

Runs can be ‘trimmed’, the lower and upper speed section of graphs can removed if visually required (e.g. if tests start and finish RPM were inappropriately set) and the run re-saved.

User selectable ‘Trace Shift’, the last 10 trace sets are always displayed (each new test trace ‘shifts’ the oldest one out of selection) - great when performing comparisons.

‘Auto Load’ your graph after a run – can be selected to automatically switch to the graph display after each run or you can opt to do as many runs as you like in quick succession and analyse as a graph later. A brief test summary is also immediately available after each run.

Onscreen graph legend to rapidly identify trace set colors and filenames and a run summary is available to give the key data for all the selected runs in one concise table.

Data corrected for weather conditions with world standards (SAEJ607, SAEJ1349, DIN70020 or uncorrected). The environmental conditions and resultant correction factor are stored with each run. Data can be manually entered or ‘Weather Watch’, automatic updating weather station is available as an option (USB to PC).

Data Acquisition

Data acquisition of 5 analogue input voltages is incorporated (‘common’ ground). This allows the monitoring of variables such as air fuel ratio, exhaust temperature etc.

Inputs can be 0-5V or 0-15V (each channel has a range selection switch)

Resistive sensors, such as standard automotive temperature sensors, can be easily connected as each channel has a selection switch that enables an internal  ‘pull up’ resistor (just connect the sensors 2 wires directly to DYNertia3!).

A data logging function is provided allowing the 5 input channels (plus the digital RPM input) to be logged to the PC. The logging rate can be set and the data is saved (with field headings included) as a text file (.CSV) for later analysis in Microsoft Excel etc.

Input data can be viewed separately (can even be displayed on separate screen if dual monitors used) or is available whilst performing testing. Minimum and maximum alarms can be set to alert if sensors detect anything outside an acceptable level (lean mixtures, engine temperature overheat or oil pressure loss as examples).

The input channels are fully scalable, even for non-linear sensors. Many sensor choices are already pre-calibrated and DYNertia3 software doesn't just display the input voltage measured, a table for each input allows it to be calibrated and displayed in any units you choose (eg Lambda, air/fuel ratio, degrees, PSI etc).

For configuring non-linear sensors, such as automotive style temperature sensors, there is a tool provided that just requires 3 test points (more can be used) to be entered and it creates a full calibration table.

Simple screw type terminals on a removable terminal plug allow for quick and easy sensor wiring. Both a 5 volt and 12 volt output to power auxiliary sensors is also present if required.

An additional digital channel is provided if you wish to have engine RPM directly measured (via a hall sensor or DTec’s ‘RPM adapter’). This option can help reveal tyre slip/growth on a chassis dyno or centrifugal clutch engagement RPM. There is a dedicated analysis screen to examine slip/tyre growth.

 File Management

Designed to perform testing quickly- common user settings are saved to reduce set up times and any personal notes you’ve entered in the provided form (general, vehicle, owner details etc) can be saved as a ‘template’ and applied to other runs to save re-entering the details, even copies the run’s set up details. Files can also be set to ‘auto name’, the file name simply increments with each test, no need to even re-enter a name.

Advanced previewing function (‘File explorer’) shows graphs, summary details and the data table of all saved runs, this allows quick selection for loading into the main graph screen or for file management purposes. A cursor is even available to highlight points of interest on the graph and indicate that same location in the data table- no more browsing through cryptic file names!

User configurable directories- have as many separate directories to store your runs in as required and file protection can be applied to prevent individual files from being accidentally changed or overwritten if required.

 Printing

Color print outs of your chosen graph or overlaid graphs (up to 5 printed on same graph) is only a mouse click away, complete with preview. A report page is also generated that has a summary of all the important test conditions, max readings, date, time, company logo, graph notes etc.

Printouts includes trace sets legends, colors and filenames, the graphs ‘grid lines’ can even be turned off!

Comments can be placed on the graphs to appear on the printouts.

Printing of specific areas of interest can be performed using the manual ‘zoom’ function.

 Additional Functions

‘Point by Point’ testing mode for brake style dyno’s allows recording of individual data points at the press of a button. These individual data sets are then combined to construct a conventional trace for easy analysis and comparisons.

For dyno competition entertainment, after a run maximum power and torque can be displayed in large format for crowds to easily see (result in both imperial and metric units).

Graphs are fully auto-scaled, Power, Torque and RPM scales are automatically configured for optimal display.

Flexible options for performing a test; a run can be from ‘start’ command to ‘stop’ command or from ‘start’ command to zero power. A minimum speed can also be specified and data below this will be discarded, this eliminates any different start points of tests due to operator error.

All dial gauges have digital displays incorporated.

Gauges display ‘real time’ data during monitoring or setup. Ideal for steady state tuning with a brake type dyno! (only RPM displayed  'real time' in inertia mode)

Data ‘Smoothing’ that is applied to the power traces is adjustable to ensure you don’t miss out any detail but still end up with optimal appearing graphs.

DYNertia3 is fully isolated (optically) from the PC, this helps prevent any damage to the PC from incorrect connections (power DYNertia3 from a battery source for this full isolation!). DYNertia3 is also protected from reversed polarity supply connection.

A ‘system in motion’ (“Run”) output is available that is active as long as the flywheel is rotating, or a function is used that may result in rotation. This can directly control a relay to operate safety control systems/warnings if required or for automatic fan controls etc.

An ‘Auto Brake’ output is available that can directly operate a relay for an automatic brake (e.g. eddy current) for slowing the flywheel down if you wish, or an automatic cooling fan for cooling friction style brakes. The time it’s active for after a run is adjustable in the software. The output can alternatively be operated manually in the software (brief pulse or continually).

A ‘user controlled’ output is available can directly operate a relay, it is manually turned on or off from the software and can be used for any general purpose function e.g. remotely turning on a cooling fan, pumps wheel clamps etc.

Tools to work out the moment of inertia of your dyno system, calibrate non linear sensors and for analysing relationships between  power / torque / RPM are incorporated.

Keyboard ‘shortcuts’ assist with easy operation and an inexpensive and commercially available remote ‘page turner’ (the device often seen used for PowerPoint presentations) can be used as a remote control that can start/stop runs, turn the gauges on/off and allow automatic file incrementing (no need to type in a new name). Very convenient if operating both the vehicle and the dyno single handedly.

There is a “losses” function that can be used to measure and apply a correction to data for mechanical losses in your dyno system like friction and windage (typically very small) even or/and for driveline losses due to friction.

Back to Dyno Page

 

Home | DTec Products | Gallery | Tech Articles | Downloads | Links | Purchasing / Terms | Company Profile | Contact

Send mail to contact@dtec.net.au with questions or comments about this web site.