im wanna do it just for looks really, as i seen it done on a VR..prob a baught one, but cant be to hard to make...can it?get 2.5in PVC pipe cover it in wax and put carbon ontop of the wax, once it drys then dip it in water and slide the carbon fiber pipe off of the waxed PVC pipe..or similar pipping..thats what im gonna try to do, or use an old intake hose..
The thing about carbon fibre is its light and strong, but only half of the finished product is fibre, the other half is resin. I would think it would be massively expensive to make anything out of carbon fibre, just find out how much a square meter is as you'll need quite alot of layers to make something, in the same way as fibreglass. Then there is the next point, strength. Part of what makes carbon fibre have the properties that you find out about is the way its made, with moulds where the resin is applied, carbon fibre worked in to into it then layers of resin a fibre worked together with rollers, finally then being subjected to pressure and a little heat to fully cure it. Otherwise you basically end up with something that has about the normal strenth of some fibreglass - maybe. The other thing to consider is resin. I know that some fibreglass resins are only heatproof up to a point, but if they were exposed to enough heat for long enough(an engine bay, near and exhaust for long enough) the resin tends to break down and bubble. So you need to make sure you get the right stuff and it apply it the right way
Dont get me wrong carbon fibre looks good and I want to make a front splitter/spoiler for my beetle (the flat type that are level with the bottom of the car), but I will make it out of ply, coat the ply with fine fibreglass and then carbonfibre, so that its strong, waterproof and looks cool.
So depending on the application/design of the inlet you want to make might depend on how worth it it will be. If you were doing it for looks and could get mild steel pipework made, you could then just use a single layer of fibre with resin over the top, that way you'd have the strength without the cost of massive amounts of CF.