ROM Hack type of .dat file?

[colt05]

I have a Japanese 3DS game and I'm trying to figure out how to translate it. I used NTR CFW with it and discovered that it loads a .dat file, but I have no idea how the .dat file works.
I opened the file with HxD, and it seems that the .dat has a CTPK file in it that contains .tga files.
The first 4 bytes are 04 00 00 00.
How do I extract the file?

EDIT: Found another one that seems to be a SARC (but not starting with 04). It won't open though since the header is messed up.

 

[colt05]

it seems to be compressed, since there was another one with a SARC in it that was invalid

 

[FAST6191]

The name of the game tends to help here both in general and in this case as .dat is probably second only to .bin in the generic extension stakes.

For future reference you can also often tell compression by how well the file compresses with something else (make it something a bit more basic like plain zip rather than high end 7zip).

 

[DRAGONBALLVINTAGE]

I know its old!

PS2 NCAA FOOTBALL AND MADDEN GAMES USE .DAT