Le Mans Ultimate

[MichaelBFS]

I found the files from the new simulator. It's Le Mans Ultimate.  The structure is very similar to rFactor2. But they are slightly different.
All the cars and tracks in the container are in .MAS format. I could not open them. Most likely they are also encrypted like the new add-on files for rFactor2.

I unloaded all the cars and a couple of tracks. Probably the most valuable thing here is the detailed tracks.

If someone can extract and convert to 3dsmax that would be great.

 

https://modsfire.com/zw63HxVSBl30h3H

https://modsfire.com/F9aU44I46FJ6lwG

https://modsfire.com/HM8EN9UKa8GEfyX

https://modsfire.com/741sV4i5IJGK6y8

https://modsfire.com/Hah0WWwnkS88Te7

https://modsfire.com/AhrtlefFBdA2e8u

https://modsfire.com/E9hb1VH0C4N0NS9

https://modsfire.com/Joo1ZK9GCldH49M

https://modsfire.com/oo52r7fBhNEHCBI

https://modsfire.com/j06b43N0qr6AU3j

https://modsfire.com/4FHnL5Grt9QK3RG

https://modsfire.com/LGx39Kmr2q49Qri

https://modsfire.com/49PKQKsC2i697Ba

https://modsfire.com/5M57Dcz4g78XBMT

https://modsfire.com/74222wvKVubnJoE

[Ekey]

https://github.com/nlhans/MAS2Extract/tree/master

In https://github.com/nlhans/MAS2Extract/blob/master/MAS2Extract/MAS2Reader.cs#L73C36-L73C51 you need change magic GMOTOR_MAS_2.90 to LMU100_MAS_2.90

Edited February 29, 2024 by Ekey

[MichaelBFS]

have you tried this method? did you manage to unpack these files?
maybe there is a ready exe file for unpacking?

[h3x3r]

I did on "Monza_2023\0.906\assetsMAPs.mas" but it doesn't unpack.

It says: Failed to open MAS archive. Is it a rFactor 2 archive?

Release.7z

Edited March 1, 2024 by h3x3r

[MichaelBFS]

I got the same error. This method does not unpack the files .MAS. I was only able to unpack a few textures from the cars folder - the "upgrade" folder. The main car and track files this unpacker cannot unpack... they are encrypted by another method....

Edited March 1, 2024 by MichaelBFS

[king448]

On 3/1/2024 at 11:50 AM, MichaelBFS said:

I got the same error. This method does not unpack the files .MAS. I was only able to unpack a few textures from the cars folder - the "upgrade" folder. The main car and track files this unpacker cannot unpack... they are encrypted by another method....

the texture files you were able to unpack were any of them the liveries for the cars?

[MichaelBFS]

Yes, it seems there were liveries for the cars. I think they used the same encryption method as rfactor2.

[whateverfloatsyourgoat]

On 2/29/2024 at 4:34 PM, Ekey said:

https://github.com/nlhans/MAS2Extract/tree/master

In https://github.com/nlhans/MAS2Extract/blob/master/MAS2Extract/MAS2Reader.cs#L73C36-L73C51 you need change magic GMOTOR_MAS_2.90 to LMU100_MAS_2.90

How do you even use that ? I'm new to modding stuff from RF2. I'd like to get my hands on the LMU liveries but I don't know how.

[Durik256]

I didn’t delve into the topic, but if you just need to replace the magic check in the code, then I made the replacement in line 73 in the MAS2Reader.cs file:

if (fileTypeString == "GMOTOR_MAS_2.90")

to

if (fileTypeString.EndsWith("_MAS_2.90"))

so it will be universal.

I also build this in VS:

MAS2Extract.7z

Edited June 10, 2024 by Durik256

[whateverfloatsyourgoat]

The MAS2Extract exe doesn't work at all, the command prompt does nothing - I put everything in documents/MAS2Extract, also tried to put all that stuff directly in one car directory (Caddy VSeries), nothing.

 

I know how to use QuickBMS though, but no script for LMU so yeah, I'm lost.

 

 

Edited June 10, 2024 by whateverfloatsyourgoat

[shak-otay]

While the extractor works for Aston_Martin_vantage_amr car-upgrade.mas car.mas seems to have another encoding:

changed MAS encoding

[whateverfloatsyourgoat]

2 hours ago, shak-otay said:

While the extractor works for Aston_Martin_vantage_amr car-upgrade.mas car.mas seems to have another encoding:

changed MAS encoding

I fiddled with MAS2Reader and put the LMU100_MAS_2.90 where it belongs but it just won't work. MAS2Extract opens then quits immediately; even when opened as admin.

 

When I do try to open the upgrade mas file with open -> select a program -> MAS2E I get this result :

 

 

I don't know what to do anymore lol

 

So maybe if someone managed to do the impossible on my end, could you please upload and share all the LMH / LMDh skins ?

 

 

Edited June 10, 2024 by whateverfloatsyourgoat

[whateverfloatsyourgoat]

Bump, who knows maybe someone will see this.

[09williamsad]

On 6/10/2024 at 5:10 PM, whateverfloatsyourgoat said:

I fiddled with MAS2Reader and put the LMU100_MAS_2.90 where it belongs but it just won't work. MAS2Extract opens then quits immediately; even when opened as admin.

When I do try to open the upgrade mas file with open -> select a program -> MAS2E I get this result :

I don't know what to do anymore lol

You do have the tool working, as it would have exported those files to the location where the tool is run from

Or you had the -s parameter in use, so it listed the files without exporting them.

 

The problem still remains that car.mas files have car-upgrade.mas different formatting, so MAS2Extract with the LMU100_MAS_2.90 tweak is not compatible with them.

For those, you would need too recompile MAS2Extract with a different encoding as change pointed out by shak-otay.

Edited December 11, 2024 by 09williamsad

[DAWEN]

Can it be extracted, Masters?

[IRLM90_]

I found this topic on Google and would like to share some information:
The original hex code from car-upgrade.mas is '6d 31 1f 21 5f 1f' on the first line. Change it to "66 31 05 44 20 7D" and it will open.

However, that's the same thing that MAS2EXTRACT used, so there's nothing new here.

 

car.mas and the other crypt files have a different signature.

The first and second ones are the same, except that on 0D 0000000 there are other letters.

Edited August 2, 2025 by IRLM90_

[liam02]

Can someone can extract . Some modders from ac converted those models to ac mods. I dont know how they did that.

[Marb]

Bump

Am I right in assuming no progress has been made in finding how to extract the LMU car.mas files then?

[valentim725]

We are very close to decrypting and extracting the content.

[valentim725]

We have come this far with practically everything decrypted. Who can help us create the tool to extract the content?

FUNCTIONSSS.rar

[valentim725]

On 15/09/2025 at 04:34, liam02 said:

Alguém pode extrair. Alguns modders do ac converteram esses modelos em mods ac. Não sei como eles fizeram isso.

They use the ninja ripper. I did it myself.

On 25/01/2026 at 14:50, Marb said:

Ressalto

Estou certo ao presumir que nenhum progresso foi feito na descoberta de como extrair os arquivos LMU car.mas?

See the posts below. We reverse engineered it and found all the functions and keys for decryption.

[valentim725]

This is the correct workflow.

LMU_MAS_Format_RE_Report_v2.doc

[valentim725]

I sent it to some friends, but it seems that none of them are interested in this game. Well, folks, we're doing what we can, and we need help. Anyone who can help, we'd be very grateful.

[Miguel Cardoso]

On 2/8/2026 at 12:25 AM, valentim725 said:

We have come this far with practically everything decrypted. Who can help us create the tool to extract the content?

FUNCTIONSSS.rar 657.18 kB · 15 downloads

How use this?

[shak-otay]

5 hours ago, Miguel Cardoso said:

How use this?

If you are not a coder forget about it. It's debugger output as C code:

Quote

   if (local_500 == (FILE *)0x0) {
      pauVar29 = (undefined1 (*) [16])&local_400;
      if (0xf < uStack_3e8) {
        pauVar29 = local_400;
      }
      FUN_140611110(param_1,-1,0x141093aa8,pauVar29);
    }
    else {
      if (*(code **)(param_1 + 0x6e) != (code *)0x0) {
        (**(code **)(param_1 + 0x6e))(0,0,&DAT_14139b198);
      }
 

Imho such decompiled code is more confusing than directly tracing through assembler. (Just my personal opinion.)

Most interesting part is the function pipeline given by them:

Quote

Here’s the function pipeline graph (MAS open → header decode → entry decode → decompress) with the actual function names you’ve validated. I’m only using what we’ve already proven in this chat.

MAS pipeline graph (functions + data flow)
0) Callers / entry into MAS system
FUN_140612b40
FUN_140609d00
   │
   ▼

1) MAS entry loader (reads header + dispatches entry decode)
FUN_140613020   (MAS entry loader / dispatcher)
   │
   ├─ alloc puVar6 = malloc(plainLen+0x10)
   │
   ├─ if compressed branch:
   │     alloc pauVar9 = malloc(compLen+0x10)
   │     read src → pauVar9   (COMPRESSED BYTES)
   │
   │     ▼
   │   [Transform before decompress]
   │     FUN_14061cfb0(
   │         RCX = &ctx[0x158],
   │         RDX = pauVar9 (or RBX/R14),
   │         R8  = len (RSI),
   │         R9  = seed64 = [ctx_base + 0x198],
   │         stack+0x20 = variantFlag
   │     )

...
 

You would need to take part at their chat to understand the problems.

From my experience with similar problems it is essential/the solution to find the buffer with the decrypted data, if any.