I just got to let every one know that the new Thunder Alley ceramic coated/ spark arrestor 96 db version just rips. I have heard the Thunder Alley pipes were loud in the past. Bob Murray has the new permanent baffle insert rated at 96 db that works very well with his pipe. I was lean top to bottom when I first put it on so I was expecting some seat of the pants gains when I got the jetting right. I rejetted and Wow! This pipe rips from the bottom up and pulls hard all the way thru. The stock pipe with a baffle does not stand a chance. No comparison. Thunder Alley is well worth looking at.