Redline GTP – the mod Papyrus didn’t want you to see


My memory has faded and the exact details of the launch and controversy surrounding it have been lost to the sands of time, but in early 2005, after it had been announced that Papyrus would venture off into the unknown and eventually create iRacing, numerous NR2003 modders would attempt to turn the NASCAR sim into a platform for many different types of racing disciplines.

Through a joint operation that saw lawsuits get thrown at a few different individuals for violating NDA’s and certain terms of the End-User License Agreement, one of the results of the ugliness surrounding the NR2003 modding scene was the Redline GTP mod.

Requiring a clean, alternate install of NR2003, patched to version, the original version of the Redline GTP mod featured the four most prolific cars of late 80’s Group C Endurance racing – as well as an EXE that was illegal to create BUT not illegal to freely distribute. The mod, created largely in part by Redline Developments, a subsidary of Team Redline, significantly altered NR2003’s default physics in an effort to accurately simulate Group C Prototypes. During the development of the mod, Redline also discovered unused lines of code in the exe that hinted Papyrus was hard at work at implementing some sort of fog and rain system, among other things.

Even though it is dated by today’s standards, the original Redline GTP v1.0 mod is a fantastic look at the capability of the GPL engine. These cars are an absolute blast to drive, even with prehistoric FFB effects and graphics that simply don’t cut it in 2015. They have an insane amount of downforce, hit ridiculous speeds, and have much more realistic slip angles than what you’ve seen in the vanilla game.

The mod was quickly pulled down after legal threats from FIRST Racing – whom you now know as iRacing. During the development of NR2003, certain members of iRacing were able to copyright the source code to NR2003, effectively preventing people from editing and distributing what we now call “stand-alone mods”.

A short while later, the mod was re-uploaded as “Redline GTP v1.1″. The mod was quickly converted back into the format that Papyrus allowed, and instead of using the completely custom physics as the original, the four Group C cars were relegated to use the Project Wildfire Trans-Am (pta) physics, effectively making this no different than any other NR2003 road racing mod.

Modding NR2003’s .exe file to alter the handling of cars in-game is not illegal, which is what the Redline GTP mod is. However, it was entirely possible to crack the .exe on top of changing the game’s physics to your liking – effectively making it possible to redistribute an entirely different game, using NR2003’s source code, without requiring people to own NR2003. You could not release something like iDT’s Champcar Challenge using NR2003.

iRacing took this issue to court and pressed even further, claiming third party modders using NR2003 as a base could potentially surpass the quality of what they themselves could do with iRacing, and it would “take away potential sales.”

The results, again lost to the sands of time on RaceSimCentral, show iRacing lost to these individuals in court. However, due to the age group of most people involved with modding an obscure NASCAR game, iRacing’s bully tactics were enough to scare people off from ever daring to make anything for NR2003 that wasn’t a paint scheme or a track.

Eleven years later, the EULA and all other issues related to modding NR2003 are no longer valid.

Thanks to AllNR2003, here’s the original Redline GTP mod, in all it’s glory.

The mod includes detailed instructions and you’d be wise to read it.

Here’s how to add more tracks to the mod (it’s a little light on the track roster)


7 thoughts on “Redline GTP – the mod Papyrus didn’t want you to see

  1. Hello,

    If you have a look on Youtube and search for Redline GTP, you’ll see I’ve tried putting together one-stop-shop updates for this awesome mod. The video descriptions have all the info, from where to get through installation. I’ve also spent eons updating car information and performance (ingame and out), and redoing default setups and ai setups.

    Good to see GTP publicity. We need this quality of work, hopefully psander can revive it in Assetto Corsa… though I’d also love to see it converted to rF2.


  2. ps: The download only provides car folders, it lacks everything else and there are no instructions. I do have the full 1.0 uploaded but it includes the 6 tracks so it is a larger file. Still, I never got it to work because there is something that needs to be done with regards to Windows security that if not done BEFOREHAND it will never work, and the game, otherwise it won’t load so I was very much looking forward to a step-by-step solution.


  3. It is simply not correct that the legal GTP 1.1 uses Wildfires Trans-Am (pta) physics.
    Because just like GTP 1.0 it uses a special GTP_Launcher.exe to start the sim.
    This launcher alters the physics to a special (gtp) physic.
    The difference between the 1.0 and 1.1 launcher is only that the “non-legal” 1.0 launcher doesnt check for a NR2003 install before the GTP is started.


    1. I used to have the installer but deleted it like a scrub. When I wrote the article I thought it linked to the full installer but turns out it didn’t.

      One of these days someone will send it in.


  4. Just to show how far out descriptions of the GTP 1.0 vs 1.1 often is:

    Quote from SomeoneWhoHaveNeverStartedGTP
    “Does 1.1 drive differently? Much differently.
    1.0 has real physics for the cars. 1.1 does not have real physics.
    1.0 had a launcher that you used, where you would choose the car make you wanted to use (such as Mazda) and it would load up the physics specifically for that Mazda car if that was what you chose.
    1.0 also had tracks specifically made for it, including night tracks with working headlights on the cars.
    So to get the most out of that mod, you’d want to use 1.0, which was basically like its own game, with the few tracks it also had.
    Other tracks could be added into it, but it took a little work and added files to make them work properly.
    But it has been several years since I used the mod. Maybe someone else can advise a best route to take with it.
    But yes…. 1.0 is the better version, by far. Real physics, specific tracks, its own screens..etc.”

    Correction by fortine_oo
    “GTP V1.1 retained a modified NR2003.exe that utilizes 4 different car physics, it does not use a pta.exe.
    Perhaps the confusion is due to the OWR mod, which originally used a modified NR2003.exe.
    The OWR mod didn’t receive a legal release to modify the NR2003.exe as Team Redline’s GTP mod had, so the OWR mod was converted to use the pta.exe. (-)
    Everything available in GTP V1.0 is 100% completely cross-over compatible with GTP V1.1.”

    LikeLiked by 1 person


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