Exhaust mod. ?

[BackTalk]

I have an extra HPI exhaust (muffler) that I would like to try my hand at a mod. My question: which way do I go? Restrict it more or open it up more.
Any help?
B/T

 

[aj200415]

depends, do you want more top end, or more bottom end power?

 

[BackTalk]

bottom power

 

[jon2]

How do you plan to modify the pipe? Normally a different header is what can be tuned. The actual pipes are designed for a certain RPM range.