Any of yall used one of these?

The mandrel bends are made with a bunch of insert dies stacked on a cable, you put them in the pipe and use a bender to bend the pipe and it cannot crush as the inserts are inside the pipe. Trick is pulling out the mandrels. Usually the machine pulls them out with a hydraulic ram. If you fill with sand and use shoes on the 'pins' to spread the load, you could bend them. Or old school and make a bed of red hot coals, stoke it until the pipe gets red hot and wrap it around a pole. I saw a motorcycle guy do that on some really thin wall stuff full of sand.

Rusty, the dies need to be smaller, maybe some newspaper/sheet metal formed in there to get a good support on the smaller OD exhaust tubing. If you can support the sides 100%, you will prevent a kink as it will have no where to expand to.