Mandrel bent Versus Normal exhaust

Stan,

Mandrel bent means the pipe is bent evenly all along meaning you are getting a constant 2.5 inches. "Cheapy" bent pipes have "corners" where they er bent reducing the diameter. Think of a kink in a rubber hose, it is this type of effect.

Get the mandrel bent.

Jim.

Unless the bends are greater than 90 degrees (real bad) an option to 2.5" with mandrel bends would be to go 3" with normal bends. For your application the real world difference would be negligible, but it's your money.

I agree with CJ, its your money, but your not chasing .01 of a HP, the difference in Non mandrel and mandrel would be minute for the outlay...

Have heard that Mandrel bends have a habbit of breaking at the bends due to the extra stresses of being drawn out,not bent.Any thoughts?

There is actually less stress in a mandrel bend although the wall of the pipe on the outside of the bend is thinner. Mandrel bent tube is still bent there is just a big plug up the centre of the pipe while it is being bent to stop the pipe crushing in on it's self.

A standard bend is under more stress, have a look at how many changes in direction are around each bend, crushing, stretching, pinching. Mandrel bending is much nicer to the tube.

For a standard motor where exhaust gas velocity is not as much of an issue, I doubt it would make much difference, especially if you are running the standard exhaust manifold.