i heard that if the pipe from the cat to the muffler had rinkles where the pipe turns that it will lose power i dont know what to belive or is that true

 

Yeah, if there are any dents or what not in the I-Pipe it will mess up flow, that's why you want to get a mandrel bent one.

 

mandrel wtf is that mean is there any other name for it

 

I guess that's just the method used to make it, I know it's not a brand.

 

what is the proper name for the pipe from the cat to the muffler that 3" long pipe ???

 

It's called an I-pipe , short for intermediate pipe.

 

Mandrel bent means that the cross section width is the same through the turn as it is in the straight portion of the pipe.

In order to bend a pipe, most exhaust shops use the "push the pipe in and it will bend" method. By pushing on the pipe, it makes one 'side' of the pipe move closer to the other. This decreases the distance from one 'side' to the other. What actually happens is the pipe becomes oval through out the turn. You can lose as much as a 1/2" of inner diameter at a 90* angle. This can cause a 3" pipe to flow as poorly as a 2 1/2" pipe because as the saying goes, "A chain is only as strong as it's weakest link." Goodbye.

Mandrel bends keep the pipe shape circular through a bend, as well as maintain the distance from one 'side' to the other.

I'm not sure how the process is done, but I would think that somehow they have to stretch the long 'side' of the bend. But don't quote me on that.

AJ