You don`t need a system disc 2 to run most GD-R discs, just use the swap method,
1) Remove DC cover
2) Boot to CD player menu
3) Insert GD-ROM
4) Close lid sensor and tie it down (rubberband works well)
5) Play the disc in the CD player so you hear the warning track
6) Stop the disc
7) Remove the original GD-ROM and insert the GD-R
8) Exit the CD player to the main menu
9) Start game
this has been known to work with a majority of GD-R discs.