Development Update – Dirt Racing Refresh

Good day, 

On February 3rd of this year I posted a development update to members.  One of the main focuses of that update was to address concerns related to the state of oval dirt racing and oval pavement racing.  I mentioned that we formed a team focused on tackling these issues head-on, beginning with dirt, and we have internally been referring to these efforts as “dirt racing refresh” and “oval racing refresh”.  It actually is more than just a refresh, but we didn’t want to call it overhaul either, because that is also not the case.  It has been a couple of months since the previous update and we are now cautiously optimistic that Dirt Refresh will ship in June, so I wanted to provide more details on what to expect.

Dirt Racing Refresh:  


  • We updated  the water content of the soil resulting in a greater difference in soil strength between “fresh” and “dry.” This results in a bigger variation between driving on the ‘fresh or tacky’ part of the track vs the ‘dry or slick’.
  • We updated the relationship of the dirt surface and the tire allowing for a more “in the track” feel.
  • We updated variation in track wear / track prep.  There is a larger gap between low track wear and a lot of track wear as a result of laps being run.
  •  We added track bumps through dirt and water variation. This adds a layer of variation in track prep session to session.  Some races may have a smooth surface (think what is on members now) and some races may have a more rigid and bumpy surface.  Bumpiness may vary session to session and change slightly throughout the track wearing process.
  • We added water variation scaling.  This is another variable that may be noticed session to session.  Think of a water truck watering the track.  The higher parts of the track may be drier than the lower parts due to gravity and the water seeping to the bottom.  For example, the top of the track may be drier than before and the bottom may be wetter.  The water truck is not a perfect science so it may vary in how dry or wet specific parts of the track are race to race.


  • Every oval car that races on dirt was tuned either through tires, physics, or both.  This includes Stock Cars (Current NASCAR Cup Cars, NASCAR Trucks, ARCA Menards Impala) and as a bonus also includes the Off-Road Trucks (Pro 4, Pro 2, Pro 2 Lite)
  • Tire wear was introduced to the Dirt tire model, and independently tuned per vehicle. Whether a 75 lap super late model race or a 30 lap 360 sprint car race, paying attention to your race length and tires will be important.
  • Some vehicles received sound improvements and updates.

New Damage Model Enabled:  

  • Super Late Model
  • Pro Late Model
  • Limited Late Model

New features:

  • The ability for Hosted Racing hosts to disable the virtual mirror for their session.

Bug Fixes:

  • A handful of dirt tracks had dark seams around their perimeter.  This was visual only and did not affect the physics.  This has been fixed.
  • Remote car wheels could seem to twitch oddly.  This has been fixed.
  • Certain tracks did not have collisions applied to their catch fencing. This has been fixed.
  • Rebuilding DTI data to fix odd cushions at certain tracks.
  • And more…

While it won’t make our “Refresh” release, dirt AI is also in the works, although there are technical hurdles we still need to overcome before we’re ready to make it available.

As I mentioned last time, work is underway on an Oval Refresh as well.  This project has similar goals to those achieved with the Dirt Refresh: a thorough assessment and tuning of all systems that combine to create the oval racing experience, in particular dynamic track and its impact on multigroove.  Progress is also being made generally in regard to tires and the model.

We are also making significant progress on our new weather system along with rain and are still hoping to release these features later this year. This will bolster our service as a whole but more directly impact the road racing side of things. We also have several exciting tracks in our pipeline including we are doing a little tour of Italy this week, scanning Misano as well as Mugello. (I don’t think I mentioned Mugello in my last post.)   As usual, plenty more in the works, but I wanted to simply focus on the dirt racing refresh with this update.

New dirt content will also be arriving later this year with the release of Kern County.  Kern features both a dirt oval and half-mile pavement oval on the property, and the iRacing release will include both of them.

We are really excited about the results of these efforts, and our testing team has enjoyed the improved raceability of the cars and enhanced track dynamics.  Thanks for your patience throughout this process, and know that we hear you and are working hard every day to improve the iRacing experience across our many racing categories and sim systems.

As always, thanks for being members and good racing!!!!