NASCAR Racing 5 – Beta Now Available

NR5It’s no secret that for as big as iRacing gets, with over 80,000 active members, that there’s a growing number of people becoming dissatisfied with the sim, voicing their complaints about everything from prominent physics issues, to a moderation system that is heavily biased and sometimes doesn’t work at all.

NASCAR Racing 2003 Season has been the primary alternative for virtual oval racers, despite the game being horrendously outdated and several little tweaks required for the game to be kept up to date. Previously, this was accomplished through modders messing with the track.ini files, giving the racing surface less friction, more grip, or in some cases, artificially adjusting the weather for the engines to make more horsepower. The end result was to keep the behavior of the cars relatively in-line with the rule changes NASCAR makes to its top three series each year. While it may seem tedious, NR2003 was unlike rFactor in that the source code and vehicle physics were not easily modified, leaving modders to think outside the box and hex edit the game’s executable file in order to change vehicle dynamics.

iRacing legally pursued some of those modders, as the creator of a 2004 IndyCar mod found out, and a Group C stand-alone mod by Team Redline was pulled from the downloads page after a single day, only to be replaced by a different version that used a poor set of Trans-Am road racing physics that were packed in the original game. The rest of the modding community became scared of civil litigation, and the NR2003 modding scene fell back on simple car skins, model swaps, and add-on tracks.

In late 2014, the tools used to hex edit the game’s executable and develop new sets of physics, the same tools that landed the creators of the IndyCar and Redline GTP mods in hot water were released to the public.

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Over the span of roughly two months, a small group of individuals privately set out to create what would be known internally as NASCAR Racing 5, a complete overhaul of NR2003’s physics that focused on the 2014 NASCAR Sprint Cup, Nationwide, and Camping World Truck Series season. Data used for the mod was primarily gathered from the Stock Car Evolution rFactor mod, which was taken from Joe Gibbs Racing.

From the first beta, it was clear why iRacing pursued this section of the modding community legally. The cars had insane amounts of power, insane amounts of downforce, and relied heavily on clean air to handle properly. Lap times and handling characteristics closely aligned with real world data. Setup adjustments were very logical and almost rFactor-like in the way one or two changes could drastically affect how your car handled. Multi-groove racing worked. Aero disturbances played a legitimate role in pack racing dynamics. Road racing instantly displayed why only Watkins Glen and Sonoma were on the schedule – the cars were giant piles of shit. All of iRacing’s shortcomings in the physics department were fixed in a matter of weeks by a bunch of bored kids.

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From what I recall, the “game” went through about three or four versions, all with subtle refinements. During my time testing with a buddy, we went to a different track every few nights, with conditions identical to those that were seen during Friday practice in 2014, and could easily find ourselves in the middle of the real-life leaderboard. In particular, at Watkins Glen, both of us struggled to break into the top 10 and spent a solid two hours hotlapping as if the real world practice sheet was an Assetto Corsa RSR leaderboard. Even more enjoyable was our time at Atlanta, where the surface was so slick and bumpy that running balls-out laps saw us use up every lane of the track surface – and sometimes running up high by the wall was the safest way around.

This accuracy was a nice breath of fresh air compared to what we were used to seeing on iRacing, with everyone hugging the bottom at every 1.5 mile speedway.


Another thing worth pointing out is that the guys behind NR5 were able to dial out the wonky physics that are more commonly know as iRacing’s “New Tire Model” that make all cars on iRacing incredibly sketchy and unpredictable, even in gentle, low speed corners. In a short couple of weeks, some dudes on the internet were able to completely finish a tire model that is still considered heavily WIP by a professional development team. The end result were cars that acted as if they had big sticky contact points at all four corners of the car – also known as Goodyear racing slicks. A lot of people like to claim that harder to driver = more realistic, but a former Xfinity series champion seems to disagree with this sentiment.


Originally, NR5 was meant to be tested even further through a private online league, about fifteen guys or so putting the entirely new physics through their paces in a competitive format. However, the guys behind NR5 were unable to commit to finishing the project, and the league itself switched to vanilla NR2003 at the eleventh hour as many drivers were not experienced enough to develop all new setups for the Generation 6 cars, which were required.

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To the best of my knowledge, development of NR5 has ceased, and only a small amount of people still have this mod on their PC. From what I understand, the physics themselves are almost entirely finished for speedways, short tracks, and road courses. I’m not sure how plate racing was handled, although from one of the beta readmes, you’re supposed to change the “track type” line in the track.ini file to “4”, and the “chassis type” line in the track.ini file to “0”. There are no force feedback changes or anything fancy like that, so those who just can’t get into NR2003 due to its age – this won’t magically change your opinion of the game.

2014 tech specifications are also reflected in the Garage screen – none of your previous setups will work.

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You will need BullRing’s Generation 6 mod, any Nationwide COT mod, and a 2014 Camping World Truck Series mod to get the most out of this download, as all three physics sets (Cup, GNS, and CTS) are changed to 2014 specs. You will also need relevant carsets and updated 2014 tracks.

This download consists of the modified executable file (that’s literally all this mod is) and a few different car setups to get you started at a few different tracks. Put the setups in your Player folder and NR5.exe inside the main game directory. Run NR5.exe. You’ll know if you did it right if you get a different splash screen.

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NASCAR Racing 5 can be found HERE.

An updated version of the executable can be found HERE.

13 thoughts on “NASCAR Racing 5 – Beta Now Available

  1. I installed it in my NR2003 directory but still get the same splash screen, is it normal? The setups don’t show up in the menu and the AI didn’t really seem to go multi-groove racing when I tested it. I don’t know how I could install it wrong, it’s literally just a slide and drop :p


    1. The only thing the mod changes is the behavior of the player’s car. It is ideal for online league racing and not much else. I’m sure other people will pick up the slack once this begins to circulate.


  2. Do you happen to know WHO made this mod? I’d like to get in touch with them for a project I’m working on…


  3. Yep, having the same problem as albatar, can we can a new link to the updated version?


  4. nascar2003seasons is still in my opinion the best sim around. The long established racing fraternities have made it easy to install and set up with their tweaks and with fair and decent server and racing administration it is a blast.


  5. Also, did everything in directions, no new splash screen and CTD when I click “drive”. When I use the regular launch icon and click drive, no problems.


  6. Yea, one would think that with all the hyped up writeup, this was really something. Pretty much a half completed UI and hosed up car body that has tired sticking through the fender wells. Guess the four or so involved did not have the determination or will to complete the project or were in over thier heads and simply gave up.



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