For the S197 the best forum for technical information is the s197forum.com. There is a wealth of knowledge and some really hard core guys on that forum. Just be aware it's not like most of the other forums. It's an adult forum, so there won't be any **** when you type a nasty word. The main thing, as a new member, is to read the rules before posting and don't post in the tech section unless it's really tech, what's the best muffler is not tech. You need a thick skin if you make a mistake, as you will get ripped. If you get ripped, just go with it and don't get up on a high horse and you will be fine.
Earl