I installed my JDM ITR header yesterday and today I had 2.5'' piping installed on my civic. I asked the guy who was working on my car about the method he would be using to bend the pipes and he said its just regular bending. He also said I wont find any mandrel bending in my area, and that the closest place i could find it would be in LA. Anyway, i had the piping done. At the bends the inside of the bends are a smaller diameter. I read once about crush bending, how do you tell the difference between a crush and a "regular"?
The difference with my JDM header, high-flow cat, and MTL exhaust is night and day. I love the pull from the mid-range on up. I also have CTR cams(w/gears), V-AFC, and intake; I need to get a new ECU and FPR before I begin to tune. Any idea after all this work how much WHP I might yield?

 

i bought 2.5" mandrel bends from JCWhitney for about $15 a peice and used those. no crush bends for me