Problemes burning the oversized Sonic Adventure
 

I have ripped all the data to my PC with the serial cable, but I cant burn the game because I don´t know how do make the soundfiles smaller. (I allready extracted the track.iso file to a directory.

You need to downsize a lot of sound and few videos.
Go to ####://go.to/selfboot you will find very good instructions look for "how to downsample .sfd and .adx files.
Good luck.