Anyone can make a square or a flat piece to fit on a flat surface (well, almost anyone)..
The trick is to make something like a cold air box fit in a volume made up of compound curves.

I spent a great deal of my youth building and designing model aircraft, and picked up a few tricks here and there.
One of those tricks happens to come in pretty handy for automotive work, as well..

So, I just wanted to share my incredibly simple way of duplicating a compound curve:

Obtain:
* a bunch of bamboo skewers
* enough corrugated cardboard to cover your project
* a pack of Camel cigarettes (as evidenced by the illustrious picture below)
* some sort of a marker, like a sharpie

 

Next, cut a strip of the corrugated cardboard and stick the bamboo skewers through the grooves/holes/openings of the cardboard.
You can smoke one of the Camels at this point, if you so choose. I prefer mine with Earl Grey tea.



Inserting the skewers in every other opening will make life easier..

 

Bauce

 

Then, position that funky tool you have fashioned over the compound curve you want to duplicate, and gently push on the skewers until they just touch the surface. Hold the cardboard level.

 

Here's another shot, from the other side, for clarity:

 

Once you have captured the shape of the curve(s), all you need to do is to trace it on another piece of cardboard and test fit.
By this time, I usually consume at least two of those Camels from the pack..
Then, transfer the shape on the material of your choice and cut away..

This is how my CAI was born. I made it out of 2mm Aluminum sheting, and used sheet metal screws.
The final step was covering the outside of the CAI with shiny heat retardant material to prevent heatsoak from the engine bay.

So there.. Hope it helps someone...

PS# You can use drinking straws instead of skewers for delicate surfaces, too.

 

so simple yet so effective. great writeup man

 

smart plan. for finer detail work, you can buy various sized profile gauges that do essentially the same thing but more accurately. This is by far the best implementation of DIY I've seen though.

 

I understand, but my setup is almost free. Just stuff laying around the house.
And, thank you.

 

Great write up!

Someone else on here a couple years back posted this same technique, but thanks nonetheless.

 

Really, link?

I would love to see that thread.

 

That would be my main man Wayne. Anton actually.

https://www.miataturbo.net/diy-turbo-discussion-14/my-new-diy-cold-air-box-intake-heat-shield-35127/