I put a big gun ttr225 on. Definately a gain, but it is a full exhaust from the header back, similar to a monophone. The pipe gets larger about every 4-5". It has the quiet core, spark arrestor and new packing. Idles as quiet as stock, but is pretty loud at high rpm. Love the power gain, but have a few other mods to compliment it. Just orderd a db dawg. I would love the gain without and light weight without the noise.