Release notes

Home ] What's new! ] Suspension types ] Tutorials ] Downloads ] Data files ] FAQ ] Purchase here ] Contact us ]

SusProg3D - Suspension by Design.

Windows 8.1, Windows 10 and Windows 11
The preferred minimum OS is Windows 10 Creators Update Version 1703 Build 15063 Released March 2017

Version 5.125L (Build 1531.12)

Updates and fixes in this release.
Version 5.125M (Build 1531.12)
Fixed the "ExcelApplication Access violation" bug.

Version 5.125L (Build 1531.11)
Fixed the "Ancestor for ExcelApplication not found" bug.

Version 5.125K (Build 1531.10)
Added rectangular section springs and rearranged the coil spring input form.
Changed the sequence the various results data is collated.
Update the strut input form to better identify the strut-knuckle pivot and adjustment bolts.

Version 5.125E (Build 1531.4)
Updated the struts to allow for the strut-knuckle pivot bolt to be either upper or lower.
Fixed a bug that caused a helper spring to have the wrong type of end style and coil count.
Updated drawing the helper spring to change the colour to red when solid.
Fixed a bug that incorrectly calculated the body spring seat dimension when calculating the spring for any option except "Calculated".

Version 5.125D (Build 1531.3)
Fixed a bug that prevented entering anti-roll bar chassis mounting coordinates.

Version 5.125C (Build 1531.2)
Added additional toe link actuated suspension items

Version 5.125B (Build 1531.1)
Updated About to identify Windows 11 Version 22H2
Fixed a bug that sometimes caused an exception when reading the SusProg3D settings
Fixed a heading text error in the toeout in turn results
Fixed a bug that corrupted the Ford Twin I-Beam steering input

Version 5.125A (Build 1531.0)
Added an extra Geometry Configuration option for all suspension and steering linkages.
Added the steering wheel rotation to the Excel exports for ToeOutInTurn data.

Version 5.124A (Build 1525.0)
A new Excel group tab added
Added new A-arm config and dimensioning functions
Fixed a bug displaying large numbers (-1E6 > values > 1E6)
Added extra validation in the CMM tool for spindle coordinates
Added extra validation for live axle link lengths
Added the depiction of the track surface to the graphic.
Added alternative Excel range name prefix, 'SPG'
Added a new live axle bellcrank anti-roll bar configuration

Version 5.122C (Build 1494.2)
Fixed a bug in the recirculating ball type steering gear input form.

Version 5.122B (Build 1492.1)
Fixed a bug that sometimes caused the evaluation version to hang if opening a data file created with a registered version.
Fixed the "Ancestor for ExcelApplication1 not found" error.
Fixed the licence server registration interface to persist the host and port data.

Version 5.122A (Build 1488.0)
Updated the threaded calculations to use task manager.
Updated the calculation threads to pass errors back to the main thread.
Updated the Excel interface with additional error reporting.
Updated the registration interface with additional error reporting.

Version 5.120F (Build 1482.5)
Fixed a bug calculating caster with an upper A-arm and a lower "virtual" A-arm.

Version 5.120E (Build 1482.4)
Fixed a bug in the Delphi IDE that caused some dialogs to not open correctly.

Version 5.120D (Build 1482.3)
Fixed a bug in the trailing arm with lateral links geometry calculation.

Version 5.120C (Build 1482.2)
Corrected a compiler bug with Excel2Input and Excel2CMM

Version 5.120B (Build 1482.1)
Corrected a bug in eCalc and vCalc
Corrected the terminology in Dynamic Results from 'Roll couple distribution' to 'Roll stiffness distribution'

Version 5.120A (Build 1481.0)
Updated About to identify Windows 11
All calculations now performed in a dedicated CPU thread
Extended the caster calculation limit from 0.5R to 0.8R (28.6 degrees to 45.8 degrees)

Version 5.118B (Build 1469.1)
Asymmetric Watts linkage now allows for non-optimum orientation
Fixed the bug that caused the ExcelExport to only export a single value

Version 5.118A (Build 1466.0)
Mumford links are now full asymmetric.
Watts links are now full asymmetric.
Updated the Upright, Strut, Trailing Arm and Axle input dialogs and updated the graphic.
Replaced the CHM format help file with eWriter help file.
Added a "Stacked" option to the Display Control.
Refactored the MonoWheel code to improve performance.
Added a Cascade option for all open inputs.
Added an option to view the bellcrank centred in the screen viewing along the bellcrank axis.
Fixed a few instances where the font size didn't scale correctly on hi dpi devices.

Version 5.114C (Build 1433.2)
In the Spring dialog, changing the wheel rate didn't always "stick". Fixed.

Version 5.114B (Build 1433.1)
The steering gear input form had a data display corruption when using Styles. Fixed.

Version 5.114A (Build 1431.0)
Added Chapman strut.
Updated the strut instant centre calculations.

Version 5.112B (Build 1420.1)
Updated the bump steer calculation for struts.

Version 5.112A (Build 1418.0)
Added additional validation when using shock lengths to limit wheel travel.
Extended the Jacobs ladder to allow for multiple birdcage holes and unequal length sides.
If the torsion bar calculation fails, then show the position of the torsion bar with a dash line.

Version 5.110A (Build 1415.0)
Updated the CMM tool and added a caster rotation input.
Added an option to allow metric dimensions to 3 decimal places and inch dimensions to 4 decimal places.
Updated the axis setting input to enable changing the axis sequence.
Updated all inputs that have tabs and highlighted the active tab.
Fixed the corrupted help file topics when using styles.

Version 5.108B (Build 1399.1)
Corrected the travel calculations when using shock lengths and bellcranks.
Corrected the CMM tool to update both LH and RH tyre radius if symmetrical.
Corrected the turning radius and turning circle calculations to allow for larger king pin offsets.

Version 5.108A (Build 1399.0)
Updated and corrected the anti-roll bar rate calculations.
References used are the SAE Spring Design Manual and Chassis Design Principles and Analysis.
Updated and extended the travel calculations when using shock lengths.
Corrected the front suspension caster calculation for virtual A-arms.
Updated to the latest Delphi 10.4.2 Sydney compiler.

Version 5.106E (Build 1393.4)
The coil spring calculator tool sometimes corrupted data when switching between Metric and Imperial units. Fixed.

Version 5.106D (Build 1386.3)
The coil spring calculator tool didn't read all specified inputs. Fixed.

Version 5.106C (Build 1386.2)
When using inch dimensions the ride height input showed 2 decimal places instead of 3. Fixed.
Corrected a rear suspension caster calculation error in the CMM tool.

Version 5.106B (Build 1383.1)
Corrected the spring seat dimension when specifying the spring free length.
Added the units to the rates section of the antirollbar input form.

Version 5.106A (Build 1380.0)
Updated all the Excel interface tools.
Individual worksheet names can now be specified for front and rear, left and right.
Specified worksheet names are now read from, and saved back to, the workbook.
The Excel tools can now interface with VCalc and read and write the complete vehicle.
Added a workaround to support a 3-link live axle with a single bottom link (undocumented).

Version 5.104B (Build 1370.1)
Fixed a bug with the suspension dialog that sometimes prevented the LH/RH symmetrical checkbox showing.
Corrected a bug that incorrectly assigned the AllWheelDrive property.

Version 5.104A (Build 1367.0)
Added the bellcrank antirollbar for 4-link live axle.
Fixed the "Invalid variant type" and "Range check error" bug in Calc2Excel.
Included both input and calculated wheel alignment and instant centre data in the geometry results.
Added the driveshaft calculations in roll for deDion axles.
Corrected the anti-squat calculations for deDion axles.

Version 5.102B (Build 1356.1)
Add a lower link shock absorber for trailing arm and lateral link geometry.
Fixed the OfficeXPrt270.bpl load error.

Version 5.102A (Build 1355.0)
Revised the trailing arm with upper and lower lateral links wheel alignment and instant centre calculation for improved accuracy and performance.
Updated to the latest Delphi 10.4.1 Sydney compiler.

Version 5.100C (Build 1353.2)
Recompiled to exclude testing Assertions
Fixed a bug preventing the opening of a data file with a leaf spring

Version 5.100B (Build 1352.1)
With a new file, setting the ride heights failed. Fixed
Switching the spring units (N/mm <> lb/in) corrupted the wheel rates. Fixed
Specifying a spring rate didn't back calculate the wheel rate and frequency. Fixed

Version 5.100A (Build 1350.0)

SusProg3D now available in 64-bit.
For all supported versions of Windows 64-bit.
A small performance improvement has been found compared to the 32-bit version.

Added the functionality to input parameters to generate a 4th order polynomial to calculate the tyre radius and the contact patch centroid offset.
The required parameters are the tyre radius and contact patch centroid offset at zero camber, static camber and maximum camber.

Added a stop ring for primary and secondary coil springs. The position of the stop ring controls the transition point from the initial spring rate to the final spring rate.
Changed the spring calculation to use frequency or wheel rate to calculate the spring rate.
Removed an unnecessary Calc button and combined the spring calculation into the usual Apply button.

Excel input and output now include all four ride heights and reference points.
Previously if you were working with the front or rear suspension, then only the ride heights and reference points for that end were included. Now both ends are included.

Excel output now allows for specifying separate bump and droop, roll and turn sections.
Previously all data was in one section. This now makes it easier to export just the sections of interest.

When specifying a front suspension with both top and bottom A-arms with "virtual pivots", the calculated and specified caster can differ by a small amount.
To correct this, adjust the entered caster until the calculated caster equals the required caster.

Using File | New caused an exception. Fixed.


Your suggestions and comments are appreciated.
Email to
Please include the version and build number (in the SusProg3D About box) and operating system.