Physics Calculation Tool

This file is capable of exporting the entire physics parameter files (minus tyres) for the Formula ISI 2012 car. To be more specific, these files correspond to the HDV, engine.ini, gear.ini (optional), damage.ini and ultra chassis.ini. There is also a headphysics.ini output, but this is purely graphical (cockpit camera) and does not alter the vehicle physics. Also optional is the upgrades.ini, which is just placeholder, really, for V0.35.

It requires 5.2.7+ (strongly recommend 5.4.7) available from here.

Once you have that installed, you can open the file. The spreadsheet does make use of some macro's (although most of them are non-essential and you can use the spreadsheet without them), to make use of them, you will have to allow them in the security settings.

Once you open it, you will be greeted with a large bunch of tabs, and on the first sheet, (the "Working" sheet), you will see some basic usage instructions. To summarise, the orange tabs are the 'export tabs'. You still have to manually copy these (ctrl+a, ctrl+c and paste into a text editing software).

To create a new car, is always going to be a bit pain staking. I've attempted to automatically calculate as many things as possible, and the spreadsheet helps to visualise certain items, work is still on-going in this area too. The spreadsheet still requires a good understanding of vehicle dynamics. While it can help you get a car more accurate, it still requires good data and patience.

The general process is to go sheet by sheet, and replace data in white bordered cells with your own numbers. It’s a slow process, but completing each sheet with known quantities is a good start.

You can download it here:

rF2 Physics Calculator V0.43 FISI 2012 PUBLIC.ods

If for any reason you need the older version:

rF2 Physics Calculator V0.42 FISI 2012 PUBLIC.ods

rF2 Physics Calculator V0.35 FISI 2012 - PUBLIC.ods

rF2 Physics Calculator V0.33 FISI 2012 PUBLIC.ods

A couple more things to note:

  • If your locale uses “,” as your decimal symbol, you will need to change this in the LibreOffice settings. View comment to see example screenshot, uncheck the “Decimal separator key” in the Language settings.
  • Some cells have detailed comments, be sure to read those (view by mousing over the little red squares).
  • Due to the nature of the spreadsheet, consider disabling the spell checker. Alternatively, use the following dictionary file with LibreOffice (rF2 Dictionary.dic).
  • This spreadsheet is optimised for a resolution of 2560x1440, more is better.

Version 0.43 change-log(Published 16 August 2023):

Version 0.42 change-log(published 18 April 2023):

More accurate 'spring rates' for suspension that are of different construction. Also supporting asymmetry better and added extra digit of precision.
Add side view to 'General' sheet. Improved diffuser / rake calculation to allow for offset height plane diffuser calc's.
Copy special overrides from left to right side for easier configuration in damping sheet.
Restricting some validity ranges.
Automatic AI front/rear roll stiffness calculation, should help their balance with their simplified physics. A compensation of sorts..
Add workarounds for potential issues with how LibreOffice 'match' function works in gear sheet.. Also stop rounding 6th gear which also potentially mismatched 6th gear default ratio.
Add tyre Crr option to driveline friction % calc.
Fix some gear sheet references.
Improve support for electric vehicles.
Fix special overrides in fuel sheet.
New auto-shift code support (B1111?+)
Fix some cell references to be more logical (such as rear anti roll rate base is now taken from the manually entered 'minimum').
Fix some specials like for fender flares to always show up even if all other references are blank for said part).
More flexibility with pickup point adjustments.
Add small table to very marginally speed up fuel estimate compensation thingy.
Better support for throttle based engine brake maps.
Replaced 34,009 instances of "CHAR(10)" with 'newLine' (as defined @ working.L14), for easier compatibility with different operating systems.
NewLine is definable, and now defaults to CHAR(13) (as opposed to CHAR(10), which since LibreOffice 6.0+ is required on Windows.
Some more work on error handling (aero sheet).
Some better handling of unusual cases.
Stop outputting _Gear.ini unnecessarily.
Show 'targetBoostTorque' on engine graph along-side baseline.
Clean up some other graphs for more flexibility.
Added turbo 'efficiency' graph.
Add turbo pressure ratio target.
More space for notes.
Improve spring specials.
Automatically set "PressurePower" to 0 for electric motors.
Aero setup defined separately from other parameters to make adjustments quicker.
Added some more digits of precision for better support for electric motors.
Add more wheel dimensions.
Add "MR" (motion ratio) column for pickup point descriptions.
Making provisions for greater aero table resolutions.
Disable fuel consumption 'correction' for electric motors, which was better fixed in the code.
Lock some sheet references in aero for safety.
Add toe-links into pick-up point overrides.
Aero: Fix number display for 'max' rear wing & fender settings.
Tidied calculation for the 'highest gear ratio', mostly used as an aid in choosing lookup table data dimensions.
Add BSFC @ WOT figure to engine sheet.
Stop removing 'AI Roll Factor' lines when disabled, for easier testing via text editor.
Fix for TC & ABS specials.
If no corner springs, add small roll damping.
Automate more numbers to get sensible starting points, add more comments / value ranges.
Tweaks to fuel consumption estimation multiplier assistant.
Add space for brake booster.
Increase height for max vertical seat pos to allow for 'unusual' steering wheel / screen layouts.
Chassis filename override more accessible.
Fix missing N/A for chassis adj06.
Declutter by removing entries for detachable parts that might not exist.
Add placement for SpringRubbers
Add offset for autodownshift RPM's to split high / low in case predefined values are insufficient.
Improve toe offset and toe display.
Small tweaks to susp sheet (particularly regarding steering).
WIP steering ratio options.
Restrict Aero to be negative for left movement (drag inducing) and various directions to reduce probability of errors.
Clutch rate for AI defaults to same as player.
Fix bug with onboard ABS formatting, which would potentially prevent onboard ABS from working.
Add offset to spindle pos, relative to wheel pos.
Add 6.75" wide rim to list
Link more cell references (undertray, fuel tank, handbrakes, etc)
Extra calc's for mixture maps (more automation).
Fix for idle function calcs for eMotors.
Skip empty cells damage.
More rounding.
Better support for electric vehicles (fuel tank).
Fuel/energy consumption calc.
RamDraftMult default now auto-set.
Better way to support gear range limits.
Fuel tank size done with fuel density.
Aero, accept "Fore" lateral aero values.
Pits, Spring Rubber and Pressure adjust copied over from first values.
Add "AINegSuspForceMult" for completeness sake.
Validity enforcement eased in some cases.
Fix bug in spring specials when special overrides have no format set..
FrontRollDamping now references the front 'damping factor'.
Damper rebound now set to max height with additional offset.
Place for post-fix's in ChassisAdj sheet.
Add Average & Default Spring Mass.
Better turbo friction defaults.
Add brake-by-wire parameters. (only uses generic algorithm).
Add performance data to give quick reviews of basic car specifications (general sheet), which might be interesting as a guide or preview or maybe even BOP??
Early work on supporting more suspension types… Like live rear axles.
Changed a-arm names (forward to 'fore', and now referencing those) in susp sheet so that they reflect what's used internally for rF2.
Export button now exports Chassis.ini with brakes, tyres, rim, spring sheet (to allow for unsprung mass changes to be instantly incorporated).
Now exporting TrackConfigsBase.ini Allowing 255 camber specials.
Wheel aero lift / drag now supported in aero section. (applied at spindle)
Continued work on better live axle support
More work on TrackConfigs exporting
Early work on support for multiple aero packages
Early work on alternate suspension geometries
Add cockpitinfo camera visualisations
Enhancements to Setup sheet to more easily output sections as upgrades.ini formatted (HDV=)
Add offset for lateral weight penalty.
Show suspension arm masses.
More differential variants displayed.
Add quotes around all file names to be 100% sure of no errors.
Add more space for more pushrod adjustment locations.
Add attack mode placeholder in engine sheet
Fix some bugs with atypical setups. Such as extra check for left / right spring rates.
Fix some bugs with asymmetrical suspensions.
Fix bug in calculation of rear unsprung masses with multi-link suspensions.
Aero, show more outputs for front wing so we don't overdo airborne effects.
Support new rear brake duct settings option.
Fix ratio set specials not always showing up.
Fix div 0 on engine maps when a car only has 1 setting (speed tweak).
Added gearbox down/up shift protection feature support.
Bumpstops, using damper MR (instead of spring), also fixed small issue so that it uses the correct multiplier. Also allowing left / right differences for oval racing, and adjustable bumpstops through upgrades.
Working on slightly more flexible pickup position overrides.
Prevent removing camber specials (pivot rotations) if display specials not used.
Auto calc rear brake wear based on front. Only works well for identical compound brake pads, etc. PV/50 air density calc
Early work on setup sheets alternative setups.
Onboard Wedge adjustment (new build).
Auto-calculate some damage.ini params based on base mass, this will give very slightly better baseline figures to work from.
Allowing 48 (from 32) front suspension pickup permutations, as per a new car we're working on.
Making it easier to copy sheets by $ references. Also easier to export extra sheets, and add stuff to upgrades.ini
Allowing outer pickup point overrides.
Fix aero upgrade version outputs.
Upgrades page more useful.
Properly allowing up to 8 aliases for tracks config.
Add push to pass feature.
Fix gearshift protection params.
More tweaks to setup sheet.
Brake upgrades formatted.
Remove obsolete 'special'(s) sheet.
Move launch control parameters to 'control' sheet, where TC resides, as this seems more logical.
Move rev limit logic params to Engine sheet to be with red line values.
Removed redundant idle throttle calc from engine2 sheet.
Add new heating / cooling engine params.
Add prop shaft space.
Fix rear brake duct special and caption bugs.
Add driver weight distribution contribution calculation.
Add radiator stacking option.
Fix param name for mixture limits.
Added new P2P params.
WIP new ABS / TC.
Fix Power steer multi
More flexible formatting for spring specials for easier upgrades.
Fix body aero force distrib name.
Remove 'base' from TrackConfigs name which is somewhat unnecessary.
Added way to restrict file exports if you have a reason for it.
Tender Spring support.
Ground output fix for experiments within pTool.
Increased default value of damping for suspension components to improve stability. Now 1/2000th spring rate.
Correct error for steering location if using vertical main body offsets in Susp2.
Better matched example turbo in engine2 sheet.
Placeholder for additional undertray points.
Adding hybrid early implementation.
Fix asymmetry in displayed roll centres and anti-lift. Still works off 'assumed' suspension symmetry.
Re-arrange a couple minor things.
Electric Motor Implementation.
Reduce ICE and Motor max resolution to 128 steps. Can re-expand if needed but have never needed greater resolution in 10 years.
Add "AllBrakes" repair option.
Move Wedge to 'setup' sheet.
Fix rear toeoffset specials.
Fixed 'weight penalty' ballast stuff.

Version 0.35 "complete" change-log from 0.33 (published 5th August 2018):

Add support for gear specific Rev Limit overrides (Engine.A123)
Fixed rear wheel rate stiffness ‘frequency’. Also now include ‘anti-roll’ stiffness multipliers in special overrides.
Fix small display issue with front damper graph (table was cropped).
Aero sheet, add space for wing thickness.
Top gear in speed chart (Gear sheet), now uses max engine RPM.
Also using tyre radius from correct end of car (oops). Was using front tyre radius previously.
Add display for gearbox inertia, and gearbox shaft.
Chassis adjustment sheet improvements.
Better AI performance, peak downforce calculation (optional parameter). Fix PCD (in susp sheet, was ½)
Add some extra display elements for turbo-charged engines.
Better formatting of compressor tables in turbo sheet. Also rounding to 1 more digit of precision.
Restricted more validity ranges to reduce prevalence of typo induced errors.
Fix fender flare, rear wing special prefix to be more robust.
Postfix 0 and postfix negative in setup sheet now default to blank if you set the ‘base’ value blank. Fix missing ‘handfrontbrake’ variable when outputting HDV files.
Add adjustable rounding for suspension geometry. Also cleaner (safer) and more efficient cell referencing (fewer math operations).
Allowing formatting of special overrides for gear ratios. Added all listed Pagid brake pads from (
Fixed “adjust cords to CG” on Susp sheet. (Thanks I_Bellet from Discord!).
Fix wrong cell reference for Right Fender lift at non-zero settings. Better disabling of rear wing special overrides.
Cleaned up steering inclination in susp. Sheet.
Add "power steering ratio" option, which changes the steering shaft axis to effectively change the steering effort.
Separated AI Spring Rate Multiplier. Just in case you need to tune it manually..  Add diffuser length offset, split body and diffuser lengths.
Allow disabling of fender ‘elements’ if you leave cells with a null character (blank).
Correct search for reverse gear ratio setting when using specials.
Fix idle throttle calculation. Driveshaft length ‘correction’ removed, was more plausible without.
Correction for “ClutchInertia” more accurate contribution of the output shaft. Tweaks to damage.ini for faster setup.  Redo damper outputs to make things a bit more flexible.
Fix for multi-link suspensions. Spacing out and cleaning up braking page to make room for future enhancements.
Export All Files Macro.
Upgrades.ini file, placeholder tech.
Corrected ‘FenderFlareSetting’ to ‘FenderSetting’. Add AI max steering lock multiplier to deal with their lower quality physics which can be off at times (defaults to 1.0).
Now using LibreOffice 5.4.7
Tweaks to engine2 sheet. Showing ‘rear view’ in General sheet (for undertray, etc).
New traction control and ABS lines. Introduced in B1110+
Improved spreadsheet behaviour on ‘Spring’ sheet to deal with
More space for comments
Re-arrange a few items on engine sheet to be a bit more logical.
Put camber specials unit’s in quotes so as to make sure exotic formats work properly in the garage (such as fractions, as will be used in some future content).
Add front tyre visual in fuel sheet.
Allow displaying downforce / drag in something other than ‘ISI’ units, for wing levels graphs.
Option to remove randomness from ‘reortho’s under chassis ini, so that identical files don’t show as changed.
Fix error in Aero.L206
Improvement to Chart sizing in Susp. Sheet, which would resize to fit fonts, making it difficult to overlay blueprints or other data. Also added slight translucency to overlays.
Improved way in which spreadsheet applies Tire change options in “PitMenu”.
Account air density in load calculations in aero sheet. Improved handling of disabled graph’s,
New mixture torque map based on alternate data set.
Add AFR table (kinda hidden for now, at cell engine.AT210).
'Copy Ultrachassis’, replaced with a direct export function.
Split filename list and show on Working sheet.
Using working sheet, for those for macro’s, which is less error-prone.
Fix error when connecting pushrod to upper wishbone.