Alternate Physics 1.0 CTF for RFPE all cars (Increased CG height and more) 1.0b

Modified CTF Physics to be used with RFPE Mod 0.4

  1. exbagboy
    Summary of update 1.0b
    Installation instructions are in zip file.

    Main differences in this update

    -center of gravity height increased (more pronounced weight transfer, longer more accurate braking distance).

    -increased longitudinal slip (less wheel spin longitudinally under throttle, lateral is the same as before and based on real telemetry for gravel and tarmac)
    -cars are more neutral interaction, less understeer, more oversteer on braking on gravel.
    -increased peak grip for gravel, but lowered rolling resistance so cars are easier to rotate at lower speeds, (they don’t bog down or understeer as much at lower speeds) with just a flick of the wheel or tap on the brake can send the car in a controlled slide that is easier to recover from.

    -aerodynamics, returned side force values to original spec, this was experimental and it was too strong of a setting. It made cars less responsive to steering inputs and added understeer. Downforce is still present and higher at faster speeds so you are rewarded for pushing the car at higher speeds.
    -mid engine 037 and Stratos have higher friction lower slip angles for the rear fatter tires, easier to control less oversteer on corner entry but still a handful.

    Issues -Alpine and Renault 5 turbo rear tyre grip do not respond to modding. Also, their initial vanilla physics are different than any of the other cars so I have given up on them as far as tyres go. The other values (weight, inertia, etc are still modded)

    -fixed correct rev limits for a lot of cars, including modern WRC cars rev up to a correct 8500 rpm now.

    *For the center of gravity height I used real data as much as I could find. For example WRC Focus 07 raised cg height from 34 cm to a more accurate 40. This makes a big difference in the way the cars drive.

    Info about Dirt Rally loose surface model

    Learned more about how the handling model works by looking at an early 0.3 version of the game which included a surface_materials.mxl in the main directory. This file is hidden in the latest version. It includes all the surfaces with different depth and soil densities for loose surfaces. The CTF custom files that I’ve been editing are just the reference tyres values that interact with the surface values from the surface_materials file which has over 21 different surfaces. (including different values for the compact soil where tyre tracks are located)
    The surface file is hidden in the latest 1.23 version of the game so I cannot edit all the different surfaces so any changes that I’ve made are still tyre reference values that interact with the values of all surfaces.
    This is why setting a reference slip angle for the same tyre will still yield different results since the actual slip angle depends on the tyre value interacting with soil density, soil depth, car properties, suspension setup, weight dist. Cg height etc) and this is how it should be.
    There is a hard gravel tyre used in Greece and dry Finland and a soft gravel tyre which is used in all of wales (cold and damp weather) and rain Finland. Same for tarmac dry tarmac compound and wet tarmac compound, snow and ice so six tyres for all the courses used.

    (I want to thank Come Over Gaming for the RFPE plugin and the ability to mod the physics

    also lots of thanks to Avo77 and Forzakof for helping me with the ctf values)

    0.9 beta

    -Increased central downforce (except for Pikes Peak, these have strong aero effects already and just modified to correct drag coefficients)
    cars with aero kits are more noticeable, more grip at higher speeds, cars don't fly as high on jumps.
    -changed drag coefficient and frontal area to realistic values
    -fixed vagueness in steering for RWD cars
    -tweaked tarmac to higher grip
    -added separate CTF files for gravel/loose surfaces and tarmac, this affects suspension height and settings which cannot be changed when using RFPE plugin.

    0.8 Hotfix

    Fixed grip from copying error for all RWD and FWD cars for gravel, wet gravel and snow. Sorry about that. Too many cars.

    -Incremental increases to yaw and pitch inertia, more pronounced weight transfer, reworked values to compensate for driver and copilot weight. Used real vehicles for reference as much as I could find, as well as an inertia calculator for rfactor2.

    Increasing the yaw inertia proportional to driver and copilot,
    added weight makes cars behave better over jumps, cars were already more planted before but this update makes Finland a lot more drivable. Also, with the increased inertia it is harder to recover a landing from a really high jump.

    This is a comparison between WRC STI 0.7 version on top and 0.8 on bottom

    I recommend using the brakes mid air to adjust the pitch forward and gas to make the car lean backward while midair.

    Also cars suspension soaks up bumps better so RWD cars are not as twitchy in the rear when cornering. Cars carry more speed through corners so brake a little earlier.

    -Adjusted default braking bias on RWD cars to be more neutral, easier to trail brake,
    brake bias adjustment doesn't seem to work in game with the plugin but all other car settings work normal.
    -Audi Quattro power delivery smoother, earlier version was not very responsive at low rpm.

    This update includes the RFPE launcher and plugin.dll

    extract Alt Physics 0.8 files in Dirt Rally main folder

    Start RFPELauncher then START Dirt Rally

    (I thank Come Over Gaming for the RFPE plugin and the ability to mod the physics)

    Changes in 0.7
    (Working on downforce/aero next update)

    Increased brake torque values, brakes properly lock up on gravel.

    Tweaked Greece dry gravel, sliding friction doesn't drop off as much as Wales, (was able to get more information on dry gravel)

    Tweaked rear slip angles on gravel tires, there is more of an initial lag/understeer when tires first start to dig in heavy gravel.

    Car still oversteers under high throttle, heavy braking and high body angles.

    Incremental changes and fixes in this version

    Increased grip for Group B and Group A to more closely match WRC cars, gravel grip was lower on these cars and it was really difficult to keep on track in rain gravel compared to other awd cars. Still not as grippy as 2000s and modern WRC cars but more manageable.
    Increased slip ratio for gravel to match deep gravel.
    Longitudinal slip comes at a higher wheel spin, feels more natural, engine bogs down before reaching redline doesn't spin as freely like it is on ice. Change is not drastic from 0.5. Wet gravel will still spin more freely.
    Lateral grip remains the same as 0.5 version.

    -Audi Quattro Sport RPM revs up to 8000, HP peaks at 7500
    changed weight to correct fully loaded weight, as well as weight balance.
    -Fixed power of Ford Cosworth, doesn't feel as sluggish.

    UPDATE -0.5 (updated renault file in second folder after extraction of zip)

    -Increased mass to account for drivers, co-pilot and fuel.
    -Used Dash Meter Pro to adjust grip level to match real telemetry for tarmac and gravel.
    -Braking should be done earlier, car weight transfer is more pronounced. Trail braking and oversteer under braking more pronounced. Brakes lock up easier in corners.
    -Fixed understeer under braking in Ford Escort MKII and other RWD cars.
    -Increased rpm limit on Audi Quattro Sport to 7,500 rpm
    -Fixed weight distribution of Lancia S4 from 55% front to a correct 45% front

    Dirt Rally Telemetry using Dash Pro Meter

    If you want old damage and new physics, restore your raceload.jpk file and n2d files from the RFPE backup folder.

    Tarmac in action


    ps (friction values for ice/snow not comparable to other surfaces, ice values is higher than gravel but still feels lower in game because of other factors controlled by the game for that surface, including but not limited to rolling resistance. )

    In Codemasters defense, their grip values for tarmac in modern Rallycross are already lower than Germany and the loss of grip is 20%(more realistic) than the 12% loss on germany tarmac.
    Original Alpine A110 also has very different grip values than the rest, probably since it's the lightest of all the cars, much lower grip values for all surfaces.

    0.2 Version with all cars

    Added Pikes Peak, 2000s, Rallycross, 1960s, 1970's.

    Other changes:

    Improved inertia values for most cars and other small tweaks.
    Cars are more planted at higher speeds and bumps, subtle change from 0.1.
    Found grip values for Wet Gravel, reduced accordingly for Finland Pikes Peak and Wales. Much more fun in the rain!

    Input is appreciated!!!


    1. Have RFPE 0.4 installed, (available on this site)

    2. Extract all CTF files in main Dirt Rally folder then start RFPE mod 0.4 and play.

    I'd like to thank the creators of the RFPE mod and Forzakof for all the hard work. Also thanks to Avo77 for pointing out how to mod the rest of the cars. Would love some input from experienced sim racers and real drivers.

Recent Reviews

  1. VitaminZeth
    Version: 1.0b
    Holy crap. Got the update today (Day of release) and jesus… The 2000's Subaru feels and drives so much more similarly to the dash cams of Paul Coleman's rallies! The car doesn't slip and slide where it really shouldn't be like in 0.8 or 0.9, Left Foot Braking to induce over-steer is very much more viable and the car feels less reluctant to rotate. I was a little scared going down Pant Mawr in Wales during the first hairpin, but Jesus was the rest of the rally so smooth... And this is only in an hour of testing it! Keep up the good work and updates boys, glad to see your still kicking!
  2. sbong
    Version: 0.9
    It is good, but you have ruined slow tight corners for wales imo. It feels like driving on slicks!
  3. Ryan Eucacion
    Ryan Eucacion
    Version: 0.9
    beautiful mod. I can drive properly now
  4. Luis Ma
    Luis Ma
    Version: 0.9
    Reeeeally good but can't save carrer mode, restart and everything gone :( any suggestion?
    1. exbagboy
      Author's Response
      You can save your progress if you only use RFPElauncher, plugin.dll and ctf files. You won't have the extra sensitive damage from the original RFPE mod, modded sounds and force feedback.
      RFPE mod has a backup folder with all the original files in it. Try restoring the original raceload.jpk first and see if that works.
  5. daveneverend
    Version: 0.9
    work online or no?
    1. exbagboy
      Author's Response
      I have not tried it online yet in fear of getting banned.
  6. theravenousbeast
    Version: 0.8 Hotfix
    Note: I am using this by itself without the whole RPFE mod
    Tarmac stuff feels great, rallycross as well
    Slow gravel corners at Wales feel a bit too slippy in my opinion, I think a Sierra could get through some of those with more than 30kph.
    Also is it possible to run only the new FFB from the RPFE together with this?
    1. exbagboy
      Author's Response
      You should be able to use the Force Feedback from RFPE.
      New version coming soon.
  7. Ze70R
    Version: 0.8 Hotfix
    Great mod ! Keep it going! I just want to ask how much in % shoud be reduced the grip level on tarmac(by your researches) ?I mean is it a big difference from the Codemasters % ?
    1. exbagboy
      Author's Response
      Stock game tarmac peak tarmac drops down only by 9% for the combined long/lateral grip. That's for the V2 physics.

      V1 version(these are the early access physics for DR) it doesn't drop at all.

      The WRC tire data I found showed a 35% drop for lateral and 20% for longitudinal grip for tarmac rally recorded in Spain.
  8. aalexeskip
    Version: 0.8 Hotfix
    UFFF UNA MARIVALLA!! una pregunta se puede jugar a "modo historia" con el mod??
    1. exbagboy
      Author's Response
      IF you mean Career mode yes, it will save.
      If you only use the files I included with the mod, RFPELauncher.exe plguin.dll and the ctf files.
      It's gonna be tougher for sure.
  9. miky90
    Version: 0.8 Hotfix
    Another step towards the best modification of game physics..I'm looking forward to testing version 1.0! (-;
  10. Ret00797
    Version: 0.8
  11. miky90
    Version: 0.7
    Keep it up!
  12. Lynx2000
    Version: 0.7
    This mod makes the cars so natural to drive exactly what you would expect. Codemasters this is the feeling we want in d4
  13. prodrive
    Version: 0.7
    Thanks for the hard work guys! Everytime is getting better and better! I have some minor suggestions. Can you modify the engine tone when shifting? On default it sounds like the car is on air with zero gravity. if you know what i mean ;)) Greetings from Bulgaria ;))
  14. TiagoNie
    Version: 0.6

    I just left yesterday a message at the rfpe mod section to ask for access of the editor.. and then, I find this.. wich just did what I wanted!! Less lateral grip and more understeer!! Now it trully feels like a rally car with the weight and speed affecting the travel on gravel on each direction, not only easily controlled oversteer from vanilla, and the foward force from the power of the engine! Much more dynamic and unpredictable! And we have every and each car!!

    Thank you! I think I should donate something! How long have you worked on this? Of course some of it was not all developed by you.. great job, I believe you nailed it.
  15. miky90
    Version: 0.5a
    Best "dirt rally physics mod" out there!(-;
  16. Msportdan
    Version: 0.3b
    I'm rating this review on effort, not what it does to DR. IMO not amount of hard work can fix the mess CM left the FFB in, in this supposedly sim. But I respect the hard work of the modder and his efforts, but for me it doesn't fix DR> My apologies
    1. exbagboy
      Author's Response
      No problem, my CTF files don't change the FFB, just the physics. The original RFPE mod has changes to the FFB. I am just using their plugin to be able to use the modified CTF files.
  17. Underkex
    Version: 0.3b
    It's impressive, seriously. It's not perfect but it's near. Tarmac physics are such a big improvement over RFPE. I am absolute amazed with the feeling and how proper are the brake and accelerate zones. My only concern is about understeering in tarmac, the exit of the corners is very slow because of that, so you have to handbrake and slide in not so closed turns. I don't know if you could improve this.
    Anyway, thank you very much. After the dissapoiment with Dirt 4 I need this mod.
    1. exbagboy
      Author's Response
      The next version should fix this, added mass to the cars to account for driver weight and fuel. This also improves weight transfer and should also be easier to induce oversteer on braking.
  18. axon[]magnus
    Version: 0.3b
    brilliant mods , unfortunatey there is this loud muffled sound that gets louder the faster i move :( like someone is brushing a microphone if i lose a door or the windshield :(
    1. exbagboy
      Author's Response
      My ctf files only change the physics.
      Not sure if the original RFPE mod changes cabin sounds.
  19. Manfredorally
    Version: 0.3b
    I can't do more than two stages or less without having the "check engine light" flashing and a BIG loss of power, I am the only one having this issue?
    1. exbagboy
      Author's Response
      The increased damage comes from the original RFPE mod. I've only modified the physics ctf files from scratch. In the RFPE back up folder there should be the original n2d files which should restore original damage while using the new physics.
  20. Ferdimage
    Version: 0.3b
    Thanks for fixing the heavy gravel grip. It no longer feels like ice using the Group B 4wd cars!
    1. exbagboy
      Author's Response
      Thanks, I wish the game would let me edit wet gravel separately from heavy gravel like it does for tarmac.
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