With the Rush mufflers we typicially recommend the 1.75 or 2.00 for most riders. If you are looking for pretty loud I would recommend the 2.25, as the 2.50 baffles are very loud. We see the best dyno #s with the 2.00 in most applications.

 

Word of advice

If you are going to remove the baffles you better do it when they are new. They can be very difficult to get out. removing the packing also makes them louder