I'm sure it sounds stupid in the diesel truck world. Only had mine little over a year and have alot to learn. u guyz help out so much. As my user name says I'm a steamfitter and one of the things I was taught in my aprenticeship was restriction in pipe. It's been awile but I remember one 90deg elbow having around the same restriction as three 45s. Seems like theres 3 or 4 90deg elbows extra on some of the trucks I've seen that have stacks. Not trying to **** anyone off just curious. Is it about getting the exhuast out of the engine sooner to up the hp/torque? Just wondering