I want to replicate my K&N intake tube that is aluminum with one that is carbon. My dilemma is, do I lay up a mold from the outside or from the inside. I don't want to kill the original part to cut the mold out or off. Any ideas. The tube is 22 inches overall. It is 14 inches then bends 15 degrees then goes on about 8 more inches.. Diameter is right at 5 inches.

Shouldn't be too hard to get a tube fabrication company to knock you another one just the same up, then just wax and pva the crap out of that, use it as a mould and hopefully the carbon should slide off! id be worried about clamping the filter onto the carbon though, dont want it to tight to crack the carbon, but too loose to let air pass though the gap.