Front-view Suspension Geometry 

Progress / News(updated August 13, 2016)

August 13, 2015
  • fixed left/right kpi/sai calculation and dimension highlighters - thanks Austin
May 8th
  • calculate suspension calculation width (lbj test range) based on ride height - suggested by Tag
  • fix calc/draw elapsed tick
  • hide frame centerline
Jan 10, 2015
  • added steering calculations - suggested by Miatav8,MstrASE,A&P,F
  • increased diagram width to accommodate new Steering panel
  • added most of the steering dimension highlighters
  • added setting for showing/hiding IC/RC/steering lines while still showing the IC and RC dots
Apr 4, 2015
  • added tire sidewall compression input (Wheels/tires setting) - suggested by Horizenjob
  • added rolling radius output: takes into account sidewall compression
  • tire circumference still does NOT take into account sidewall compression
  • updated test for internet explorer (still highly unrecommended) so it will detect all IE browsers more info
  • changed Front/Rear suspension toggle from a link to a button
  • changed Reset Trim toggle from a link to a button
  • fixed some issues with displaying units
  • updated window title, now starts with 'VSusp:'
  • minor styling update for select/dropdown boxes and output boxes
  • added tire section widths: 125, 135
  • added /82 profile/series tires
  • added 10 and 11 inch wheel diameters
  • added max length for string controls
  • fixed min/max check for number inputs
  • fixed dimension highlighter/mouseover for explicit tire width
  • internal code cleanup and performance fixes
Dec 24, 2013
  • Recommend not using Internet Explorer due to max URL issue. more info
Dec 22, 2013
  • fixed ie11 drag bug (thanks Tom)
  • updated to link version 0.8 (bump value precision change in hash, added conversion from 0.7)
Dec 11, 2013
  • tweaked drag controls a bit to make them easier to use
  • code cleanup
  • packed more js into min file
  • fixed dimension highlighter font size relative to zoom
  • adjusted drag control repositioning and styling
  • updated steering knuckle tab label
Nov 27, 2013
  • updated min/max values for input controls (thanks MV8)
  • fix handling of disabled dimension highlighters due to tire sizing mode
  • add dimension highlighters for explicit wheel and tire sizes
  • fix units on a few highlighters
  • adjust various dimension highlighters so they look ok when working with small chasses
  • minor code cleanup
  • adjust knuckle shape calculation to look a little better when using very small knuckles (RC cars)
Nov 8, 2013
  • some fixes for working with very small chasses (RC cars) (thanks Jyva)
Nov 7, 2013
  • increased max control values for explicit wheel and tire diameters and control arm lengths (thanks Jyva)
Oct 1, 2013
  • fixed string control bug
Sep 16, 2013
  • fixed contact-patch-below-ground bug (thanks Cheapracer)
  • added mac strut dimension highlighers: left/right spindle length
  • moved to jquery 2.0, vsusp no longer supports IE8 and earlier
  • made close window message simpler
  • significant cleanup of code in draw functions
  • updated mouseover text for strut axis inclination
  • fixed handling of bad input values (eg. text in float field)
  • improved noscript message alert box
Sep 2, 2013
  • added type-in support for roll and bump controls (thanks Cheapracer)
  • added control for adjusting roll and bump together (thanks Cheapracer)
Aug 28, 2013
  • adjusted tool header
  • adjusted help page layout and header
  • adjusted help page styling
  • adjusted IE warning test at startup
  • changed to HTML5 doctype
Aug 27, 2013
  • feature: added MacPherson Strut (thanks Oli):
  • add some mac strut dimension highlighters (in prog)
  • add mouse position indicator to graph
  • update calc window for mac strut
  • fix controls display/hide on toggle front/rear susp view
  • disable double wishbone dim highlighters when in mac strut mode
  • mac strut scrub radii routine
  • fix bug: kpi lines not disappearing on reset trim
  • add mac strut secondary calc routines: instant centers, roll center, kpi left/right, spindle length left/right
  • improve handling of unused output controls
  • fix ground_y bearing angle problem
  • update tooltips in template
  • add some trig utility functions
  • mac strut geometry functions and robustness
  • remove some unused functions, cleanup
  • add mac strut steering knuckle polygon points
  • copy wishbone calc routine to be modified for mac strut
  • update controls displayed for mac strut vs double wishbone
  • added controls and vars for mac strut
  • added Macpherson Strut to suspension types
  • updated help page
Aug 1, 2013
  • added IC inclination angles to chart
Jan 7, 2013
  • fixed old version number bug (wasn't updating version number on load)
  • tool now loads in IE8/9. Not supporting IE7
  • fixed noscript message styling in ie8/9
  • fixed ie warning styling
  • no longer disable "redraw on drag" for IE (IE9 runs the tool fast enough to use redraw-during-drag)
Jan 4, 2013
  • added autofix for bad tire size convention value from old project links (thanks Jeff)
  • removed unused init step call
Sep 21, 2012 - Jan 2, 2013
  • did cleanup/rewrite of much of vsusp's base code, including how float precision is saved in project links, how inputs are linked to tool model, how units are handled, input-change bindings, tab switching (and active tab is now stored in project link)
  • moved url hash / project link code to a new file
  • moved body roll and bump/dive/squat to project 'trim' object
  • now using CSS for IC/RC/etc label position instead of JS
  • added various settings to project preferences: units, front/rear, show/hide, zoom
  • most inputs including chart settings are now saved in project link
  • added escaping to project link so it can be pasted into forum (shouldn't need link shortener anymore)
  • changed scale control to "pixels per mm" - but is this reasonable?
  • added IC inclination angles: angle between horizon and instant center (thanks Horizenjob)
  • made input/output boxes look a little better (styling)
  • tire size convention: opacity changes based on setting (styling/useability)
  • fixed bad wheel sizes coming from hash
  • various minor styling improvements and cleanup
Sep 10, 2012adjust chart x_axis select box width
Sep 08, 2012remove unneeded debug_print func, updated jquery.min.js and jquery-ui.min.js, removed drag.js, cleaned up redraw code and logic, fixed indicator for calc and draw timing, cleaned up indicator toggle code, cleaned up toggle check boxes
Sep 04, 2012tweak drag controls (improve css and clean js), still have highlighting in chrome
Aug 19, 2012update to version #0.7
1mm internal rounding bug (thanks Horizenjob)
turned off input spinners: number pad works again (thanks Andyawesome)
removed Roll Center Y Position from chart y-axis defaults (thanks Horizenjob)
update nav links
Aug 15, 2012namespace fixes (in progress, but workable), fix for IE load bug, fixed initial bump units (thanks Olrowdy_01, Horizenjob), remove debug panel and print messages in debug console, slightly larger control panel tab font, fixed draw toggle (prefs panel), fixed chart redraw on changed settings (thanks Olrowdy_01)
Aug 12, 2012moved nav to top of page, cleaned up layout, widened graph and chart
Mar 25, 2012fixed bad module include code, hosting changed something without notifying. Sorry all :(
Dec 29, 2011version numbers on script and stylesheet links (prevent caching old versions)
Dec 27, 2011added small tire sizes, optimized some javascript, reenabled chart
Apr 3, 2011now using YUI JS compressor
Apr 1, 2011now using local copy of main jquery lib
* front and rear suspension roll together
Sept 18, 2010added Progress on the Help page. Lots more to add later

Known problems / To Do list

Problems (todo soon):

Frequently Asked Questions (updated Aug 27, 2013)

What is VSusp

VSusp ("Vehicle Suspension") is: Very handy stuff used

Using VSusp

The Diagram

The diagram shows the Front View of the currently selected suspension. By default, VSusp shows the project's front suspension. The user can switch between front and rear suspensions by clicking the "Front/Rear Susp" link in the controls below the diagram.

The draggable left/right icon near the center of the diagram is used for controlling vehicle roll.

The draggable up/down icons located on the "Ground plane" (green line) in the diagram are used for altering the bump for each or both wheels.

By default, the Roll Center is indicated with a green circle in the diagram. The user can note how the Roll Center moves around during vehicle roll or bump/droop.

Note: To reduce confusion when using the tool, the left and right sides of the suspension are labeled opposite of those on a real vehicle. The left tire in the diagram would actually be the right tire of a vehicle being viewed from the front. Be sure to take that into account when correlating VSusp data with a real vehicle.

The Controls

Just below the diagram:
These controls indicate the current amount of bump/droop and the roll angle of the vehicle frame. The link labeled "Front/Rear Susp" is used to switch between the project's front and rear suspensions. The "Reset roll and bump/droop" link removes body roll and bump/droop at the tires. "Diagram scale" is used to make the diagram zoom in or out. A setting of "1:2" means that 1 pixel on the diagram represents a 2 millimeter distance on the vehicle. Wider vehicles may require a setting of "1:3".

Control tabs:
The Tabs (labeled "Frame", "Control Arms", "Knuckles", etc) are used to access the controls for different parts of the vehicle suspension. While the mouse is over a particular Tab, the dimension labels for that part of the suspension are all shown on the diagram. When the mouse is over a single control, e.g. "Ride height" on the Frame tab, a dimension label is shown on the diagram.

The Preferences tab is used for showing or hiding things on the diagram. Note: the more things shown on the diagram, the slower VSusp will run. "Redraw during drag" may be unchecked to make VSusp redraw the diagram less often. This is helpful for slower machines. The "Units" can be changed from Customary to Metric on this tab as well.

The Chart tab provides control over the input/output variables of the chart. The Chart is mentioned in more detail in the next section.

The Debug tab shows some output that I use for development and debugging.

The Chart

The Chart plots how variables like "Roll Angle" affect outputs like "Left Camber" over a range of values. Another useful Chart plot would be the "Roll Angle" versus "Roll Center X Location". A flat line for this plot means that the vehicle's Roll Center does not move laterally during body roll.

The independent or input variable for the chart is plotted on the X-axis, and the dependent or output variable is plotted on the Y-axis. The Chart Tab allows the user to select different variables for the X and Y axes. Also, the user may choose the range for the input variable as well as the number of points graphed.

The Project Link

Full links: The Project Link is the how VSusp stores project information. If you want to save the project you are working on, copy the Project Link text and save it somewhere: a text document, an email message, an online forum, etc. The HTML ("<a href= ...") for the hyperlink is provided, so that 'target="vsusp"' can be supplied along with the URL. This makes clicking on the link cause any existing VSusp tool to open it.

For example, this link, Ex1, contains front and rear suspension information for a test project.

If VSusp is not open already, clicking on the above link will open it in your default browser and load the data into the existing project. If VSusp is already open when the link is clicked, a dialog box will pop up and ask if the new information should be loaded over the existing project. Clicking OK will load the data. Clicking Cancel will not make any changes.

Partial links: In the project's URL, you can see "?tool=2d#0.6&project_name:...". Everything after the "#" is read by VSusp as suspension information. The Project Link box includes the data for the entire project, but truncating this data to include only particular components will allow users to load only those components on top of their existing projects.

To show how this works, click the Ex1 link, note what the wheels look like, and then click this link: new wheels. Click OK to load the new values. Note how the wheels changed.

By manipulating VSusp links like this, it is not difficult to create a base project link from which to start and a list of partial links which will modify it in different ways. This can be used to observe how a vehicle changes with different tire/wheel sizes, different knuckle and control arm combinations, or different ride heights.

About / Contact


Rob7 - need more free time