Talk Composites - The Forum for Advanced Composites

Considering Making a Carbon Fiber Intake - Need guidance.

http://www.talkcomposites.com/Topic27286.aspx

By ihave2seats - 6/18/2018 10:16:37 PM

Hey, I'm new here but have always loved cars. This project will be for an Audi S4. For our car platform however, the intake options are less than ideal - otherwise I would buy one. 

An expensive but poor design:


This intake design is ideal, but it isn't for our car and serves as the inspiration for the project:


That said, my idea is to construct a snorkel that could work in conjunction with one of the heat shield only designs as such below:



Now, while I have never done any projects like this - I am pretty handy and learn quickly. I am looking to make a permanent mould, so that it can be replicated... but I have to design the shape first. I'm sure more questions will arise, but the two that I can think of are:
1. What is the best method to create an accurate mould?
2. If I make it a two piece that surrounds the filter, how do I set the threads for the screws to bolt down the lid? (See below for example):



Thank you SO MUCH in advance!!!
By Steve Broad - 6/21/2018 7:10:03 AM

 
ihave2seats - 6/21/2018 2:05:05 AM


 
oekmont - 6/19/2018 8:08:59 AM
I thought the actual design is far from ideal? So why should replicating it be an option?

Just because there are even trickier parts out there doesn't mean that this is a good beginners project. it seems like you've come to the conclusion, that the airbox might be a bit difficult to start with. As someone who actually reached a point where projects like this are possible, I just wanted to tell you, that I think the intake is already fairly complex. Split mould, compound curved flanges, that are topics that will likely cause you problems, especially if you never done composites before.
This videos make it look quite easy, but only looking a video doesn't make you master those techniques. I really doesn't hurt to just start with a simple one piece mould. A cover ore something. Your experience from that will make any further part that much better. And it will likely save you both time and money in the end.
To the temperature topic: just making the intake out of carbon will rather increase the temperature of the air, as the tube will be (when made properly) is thinner than the original, and carbon has a higher thermal conduction coefficient than the original material.

The inlet tube isn't an issue, its the open air filter design that I see as not ideal. I believe that I could lay the material fairly easily and successfully, I would just be concerned with making the initial mould shape (I'm fairly sure I could construct the mould effectively once I have the template). Regarding temperature, I am trying to find a solution for that as I know that carbon fiber isn't exactly the best in that regard.

 
Steve Broad - 6/19/2018 9:31:09 AM
Sod, it, just go for it :-) What's the worst that can happen? You waste material and money but learn lots. If you have had any experience with woven fibre glass mat then CF isn't a lot different to deal with. The main differences are the far
longer curing times and much more expensive materials.

With regard to the fabrication of an induction system, I am in the process of designing and making one for my project car. I paint all my carbon so I am not looking for a shiny finish, which makes preparing the moulds simpler :-)




I am using plastic ducting joints and tubes to make the pattern out of, designing the system on the car so no CAD involved :-) Once I have the shape as I want it a split mould is made from the patterns using high temp resins as I will be using prepreg.

Once I had the basic shape I filled it with expanding foam to strengthen it then smoothed it out with filler. The sharp internal corners/edges will be filleted on the mould.



The moulds will be of the split variety. For small items I use a second hand electric oven sourced from eBay with a hole drilled for the vacuum tube.

I used 3D CAD to design the filter box, but there was no real need as it is pretty simple. ITG will be making a filter to suit. This service is worth considering if you have space constraints.










Filter box is made from two layers of 210gm/m2 pregreg and weighs 251gms but will be a little heavier once I have tidied it up and painted it :-). I will make the ducting with three layers as this needs to be a little more robust and has to be able to resist partial a vacuum (hopefully the system wil be good enough to supply all the air the engine requires without too much of a pressure drop).


Steve, thanks for taking the time to post your project! It looks super nice! I assume you're doing a V mount setup? It looks awesome! I hope to see your pictures of the inlet mould/result prior to paint! I really like the way you used the plastic to essentially piece together the mould and then refine it with the filler.

No problem :-) Finding plastic pipe fittings the exact size was lucky as having a suitable starting point made fabrication a lot easier. Yes, a V mount setup. You can just see the intercooler in this photo.