I have been browsing on Tower's website for a tuned pipe/muffler, for my engines to try and squeeze out a little more performance. It's hard to tell which muffler's are going to give me better performance and which ones are designed just to re-route the exhaust to a more suitable position. I don't know if these add-ons do both or if they do one or the other. I don't want to buy a pipe that is not going to change my overall power.

I have an OS 40LA, OS 46FX, TT Pro-40, and an MDS 68. I see lots of pipes/mufflers for the OS and TT engines, but it doesn't say anything about increased performance. Does anyone know how to tell which ones will help me and which ones won't. Thanks in advance for the help.