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

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

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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.
File size
759 KB
First release
Last update
4.55 star(s) 31 ratings

Latest updates

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

    Summary of update 1.0b Installation instructions included in zip. Main differences in this...
  2. Alternate Physics 0.9 CTF RFPE all cars (increased downforce, correct drag coefficients)

    0.9 beta -Increased central downforce (except for Pikes Peak, these have strong aero effects...
  3. Alternate Physics 0.8 CTF for RFPE all cars (Reworked Pitch/Yaw inertia, cars more planted) HOTFIX

    0.8 Hotfix Fixed grip from copying error for all RWD and FWD cars for gravel, wet gravel and...
  4. Alternate Physics 0.8 CTF for RFPE all cars (Reworked Pitch/Yaw inertia, cars more planted on jumps)

    0.8 -Incremental increases to yaw and pitch inertia, more pronounced weight transfer, reworked...
  5. Alternate Physics 0.7 CTF for RFPE (Increased Braking Torque/Wheel lock up)

    Changes in 0.7 (Working on downforce/aero next update) Increased brake torque values, brakes...

Latest reviews

RFPE Not starting :(
It says mfc120.dll is missing, but i have it in system. When i put it directly in game folder, mod still not starting because some other error.
The mod shows great, great promise. Unfortunately the cars all have a very snappy behaviour, which according to the author is intended, and that makes for an unrealistic and frustrating experience. Mid-engine, tranversal layout, cars are basically undriveable. Shame, as there is improvement in some major areas, but vehicle behaviour ruins the overall experience.
The cars feel overly floaty. Try going at like under 100kmh. You can not make even a left/right 4 or 5. Obviously you can just counter steer and its no problem but my point is that isnt realistic, so i doubt its realistic at high speeds either.
thanks mate what a mod
i hope you work for dirt rally 2.0 too
Not for me, the 205 t16 feels way too heavy, more than the quattro, makes no sense.
I like tough the damage physics, is there a way to keep just that?
My weights and inertia for the cars
205 t16 quattro sport
mass 1160 1290
pitch 1252.7 1896.96
yaw 1415.6 1935.0
roll 317.6 391.23
mass is total car mass with driver and co-driver and fuel.

The 205 t16 has lower mass and less inertia than the quattro.
It also has bigger rear tyres, higher downforce and feels a bit less responsive with a 900 degree turning lock compared to the 720 degree lock of the Quattro. The Quattro torque comes on early and the 205 t16 has more peak power. I'll do more testing for the next update.

My files dont have any damage changes unless you are using the original RFPE 0.4 mod. IF you use the damage mod you wont be able to save your progress. Thanks for the feedback
Been loving this mod so far but for me the 1.0 update ****ed up my gearing. Even if i change the final ratio, it doesn't change my cars top speed.. cant use the 6th gear at all on my ford focus
With this mod the game becomes the most satisfying racing sim I've played. Absolutely amazing the car hand;es exactly like it should.
Quick tested v1.0 now, some RWD cars in FInland based on loose surface CTF.
Enjoyable so far, but I've noticed weird tendency that the cars now are prone to snap oversteer real quickly which doesn't seem realistic: seconds ago the car was fighting for lateral grip, and as soon as it starts snapping it feels like it's suddently on a tarmac - happens too quick.
Thanks for the feedback, which RWD cars did you test?
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!
It is good, but you have ruined slow tight corners for wales imo. It feels like driving on slicks!
beautiful mod. I can drive properly now
Reeeeally good but can't save carrer mode, restart and everything gone :( any suggestion?
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.

work online or no?
I have not tried it online yet in fear of getting banned.
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?
You should be able to use the Force Feedback from RFPE.
New version coming soon.
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 % ?
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.
UFFF UNA MARIVALLA!! una pregunta se puede jugar a "modo historia" con el mod??
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.
Another step towards the best modification of game physics..I'm looking forward to testing version 1.0! (-;
Keep it up!
This mod makes the cars so natural to drive exactly what you would expect. Codemasters this is the feeling we want in d4
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 ;))

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.
Best "dirt rally physics mod" out there!(-;
I was absolutely gutted with the regression of the Dirt Rally physics model as the game developed., particularly on Tarmac. These two mods have transformed the game for me. Utterly gripping in Germany and Monte Carlo. Loving the way sheet ice effects the car. I'm Still getting to grips with the gravel handling, possibly a little too much steering input required, but that may well be the way I have my wheel set up. Your time and patience is much appreciated. Thank you. (will post on RFPE as well .)
Try the new version, before there was too much sliding on gravel because I was setting up wet gravel which I thought was independent from heavy/medium gravel.
Nice idea but terrible realisation! Man, gravel is not same as snow on summer tires! Your graphics are very interesting, but better just try to drive a couple of turns on gravel in real life and you'll understand everything!))) Just do it & keep your work! Good luck
You're absolutely right, the game engine has 2 spots for gravel and I thought I was modding for mud/wet gravel independently which is why it's so slippery but that value is being applied to dry gravel as well. I'll have to re-work gravel.
I am still getting similar times to real WRC times for the last section of Bidno Mooreland but I am sliding a lot more than real rally drivers.