pro circuit t-4

[j400ex18]

my t-4 says on the side that it is tunable but i dont understand how to tune it does anyone else know how

[Big - D Racing]

There are different tip you can buy, one makes it have a little more bottom, one makes it have a little more top end, one is a quiet tip, the best one though is the stock one you already have on it, that is the all around tip