there are some general steps one may follow to make a custom carbon fiber intake pipe for a Porsche 918:

1. Determine the size and shape of the intake pipe needed for the Porsche 918.
2. Choose a carbon fiber fabric that will be suitable for the application. Carbon fiber can be purchased in various forms including pre-preg, fabric, and plates.
3. Create a mold to match the required size and shape of the intake pipe. The mold can be made from materials such as foam or wood.
4. Apply a release agent to the mold to prevent the carbon fiber from sticking.
5. Cut the carbon fiber fabric to the required size and shape using a template.
6. Mix and apply epoxy resin to the carbon fiber fabric, making sure to apply it evenly.
7. Carefully lay the carbon fiber onto the mold, ensuring there are no wrinkles or folds.
8. Use a vacuum bag and pump to remove any air bubbles from the carbon fiber and resin.
9. Allow the carbon fiber to cure for the recommended time.
10. Remove the carbon fiber from the mold and trim any excess material.
11. Finish the edges of the carbon fiber by sanding and polishing.
12. Install the custom carbon fiber intake pipe onto the Porsche 918.

It's important to note that making a custom carbon fiber intake pipe requires specialized skills and equipment. It's essential to either have professional knowledge or have a professional make it for you, as the process may be expensive or dangerous if not performed properly.