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 LibreOffice.org 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 V0.35 FISI 2012 - PUBLIC.ods

If for any reason you need the older version:

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 0.35 "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 (http://www.pagidracing.com/en/home.html)
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 https://forum.studio-397.com/index.php?threads/v0-33-spreadsheet-spring-problems.60334/#post-948661
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.