There are different methods to find out gap length and offsets, but you should use the simplest one till you have better know how.

1. Use EAC gap detection function to find out second track gap length -> "in most cases 2 seconds for psx games".

2. Go to IsoBuster -> Track02 -> Sector View (RAW Mode) -> "track02 start sector"

3. You have now to go back till you reach the last scrambled data sector mixed with gap data (in most cases you can safely skip 148/149 sectors and then go step by step 1 sector backward)

LBA :42516

0000 : 20 0B 58 07 7A 82 A3 21  B9 D8 72 DA A5 9B 3B 2B    .X.z..!..r...;+
0010 : 53 5F 7D F8 21 82 98 61  AA A8 7F 3E A0 10 78 0C   S_}.!..a...>..x.
0020 : 22 85 D9 A3 1A F9 CB 02  D7 41 9E B0 68 74 2E A7   "........A..ht..
0030 : 5C 7A B9 E3 32 C9 D5 96  DF 2E D8 1C 5A 89 FB 26   \z..2.......Z..&
0040 : C3 5A D1 FB 1C 43 49 F1  F6 C4 46 D3 72 DD E5 99   .Z...CI...F.r...
0050 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
....

4. Calculate this sector samples, you know also how it works

5. The gap of 2 seconds has a length of 150 sectors, if the difference between first track02 data sector (point 2) and last scrambled data sector (point 3) == 150, then you have reached the first pregap sector, and have also your combined r/w offset. When the difference is less than 150, you have to add (150 - difference) * 588, in addition!!!

I hope I have described everything understandably.

***note: gap of 2 seconds (2:00) == 150 sectors, 1:74 == 149 sectors, 1:73 == 148 sectors... and so on!

________________________________
I believe I have mentioned everything

That is 5 * 16 = 80 / 4 = 20 samples

These 20 samples is Combined Read/Write Offset

Combined Read/Write Offset = Write Offset + Read Offset

20 = X + 667   X = 20 - 667 = -647 <-- Factory Write Offset

You must dump audiotracks in EAC always with Combined Read/Write Offset!

you have to dump this disc with EAC correction of +20 samples, don't worry I will help you later ...have no time yet

This game has 1 data track + 12 audio tracks, and EAC detects a pregap of 2 secs for each track.

Following the guide i dumped the data track correctly, but i can't detect the Factory Write Offset, that is the value EAC will use for ripping the audio tracks correctly.

In IsoBuster selecting Track 02 > Sector View (RAW Mode), the track starts at LBA: 42666.

My drive has a read offset of +667, and i understand i have to go back -148 sectors - 1 sector. But the sector 42517 (that is -149) is filled with zeros. If i go back 1 sector more i can see:

LBA :42516

0000 : 20 0B 58 07 7A 82 A3 21  B9 D8 72 DA A5 9B 3B 2B    .X.z..!..r...;+
0010 : 53 5F 7D F8 21 82 98 61  AA A8 7F 3E A0 10 78 0C   S_}.!..a...>..x.
0020 : 22 85 D9 A3 1A F9 CB 02  D7 41 9E B0 68 74 2E A7   "........A..ht..
0030 : 5C 7A B9 E3 32 C9 D5 96  DF 2E D8 1C 5A 89 FB 26   \z..2.......Z..&
0040 : C3 5A D1 FB 1C 43 49 F1  F6 C4 46 D3 72 DD E5 99   .Z...CI...F.r...

That is 5 * 16 = 80 / 4 = 20 samples

Because i have to go back 1 sector more i will add +588 samples

That is 588 + 20 = 608 (Combined Read/Write Offset)

Then the offset value EAC will use for ripping the audio tracks is +608?

Now to calculate the Factory Write Offset: 608 - 667 = -57

It's that correct? I think no

Thanks in advance.