I`ve always liked the Randall Cold Air Intake concept but found it too expensive, carbon fiber afterall, so I decided to fabricate my own using all Mazda parts I bought from ebay and the local junkyard. There are 3 parts consisting of 2 intake runners and a tapered intake trumpet on the left side that`ll fit thru the firewall.
This is the hole I made thru firewall where the intake trumpet fits thru. I used a metal hole saw and finished it off with a Dremel, I also painted the exposed metal to avoid any rust building up. The clutch line was pushed downward to clear the intake. The retaining clip was also relocated.
Here you can see the intake runner rising up towards the hole in the firewall.
Intake trumpet in place, note the gap between the 2 components, they will connect using a rubber coupling I did this so as to minimize vibration ensuring no rattles or squeeks.
Top view, lines up real good.
Rubber coupling attached. The intake trumpet sits about 2 to 3 inches above the pan so no way waters getting in there. The intake trumpet sticks out quite a bit but I`ll keep it that way. A little velocity stack never hurts.
The finished product with clamps installed, looks pretty slick huh and total cost was only $25. Like the Randall CAI, engine performance above 4000rpm has substantialy increased. Engine ping was also virtually eliminated and now produces a healthy growl under full throttle!