Well I recently put the finishing touches on a cold air intake system I've been working on / improving for some time. It ended up being a lot of buck for not much bang, but now that I've got it dialed in intake components are noticeably colder to the touch than when I started, so I figured I may as well write up what I did, if nothing else as a cautionary tale to others thinking about going down the same road not realizing how much time and money is involved to get something that actually supplies cool air. This all started because I added a dual battery that interfered with the stock intake. Otherwise I would have stuck with that. I ran an open element for a while, but underhood temps run so hot I started longing for a cold air intake. This is how it turned out:


Parts are as follows:
Weber Carb Hat w/ Tube Kit, LC Engineering Part # 1035031
Spectre Air Duct Hose Kit, (2) required, Spectre Part # SPE-8741
Spectre Air Filter Housing, Air Filter Included, Spectre Part # SPE-9833
Spectre Air Duct Mounting Plate, Spectre Part # SPE-8148
Heatshield Products Cold Air Intake Heat Shield, (2) required, HSP Part # 274400
Thermo-Tec 6" x 1' Stainless Steel Pipe Heat Shield, Thermo-Tec Part # 11675
Plug Wire brackets and clips from 22reperformance; I was told they were discontinued at Toyota, but who knows.
1'x1' x .125" aluminum plate
Liquid Nails FuzeIt, LN Part # LN-2000

Well the first step was to cut a huge hole in the firewall and install the duct mounting plate. As you can see, there is barely enough room to achieve this. The hood rib in this area lightly compresses the duct when closed, and the duct is basically right on top of the clutch master cylinder. I used a little sealant between the firewall and the plate.


The next step was to mate the rubber duct that comes with the weber hat to the Spectre duct. I cut a short piece out of the rubber duct, which is a good fit inside the Spectre duct, and used a little liquid nails to bond the two together.


Then it's just a matter cutting the Spectre ducts to size and getting them connected to the Spectre air filter housing and the Spectre mounting plate.


So once I got that done, I gave myself a pat on the back and ran it for a while. Only problem: all the components got pretty hot. I'd built an air intake system, alrighty, but not a cold air intake system. And the spark plug wires were a mess since the ducting interfered with their stock locations. Over time I kept adding heat shields, first the Thermo-Tec to the header, then the HSP to the ducting, cutting two individual pieces for either side of the air filter housing and one for the housing itself, and finally I bent up a piece of aluminum as an intermediate shield. The aluminum also gave me something to mount my plug wire holders to. It was after adding this piece of aluminum that I noticed a significant drop in component temps. And it may not look like it, but my plug wires now have a nice gap around them. The aluminum took some shaping, with a big cutout for the #2 spark plug.




Well that was pretty much it, except the duct where it bent towards the firewall was resting on the power steering fluid reservoir and uncomfortably close to the primary plug wire. The last step was to bend up a little bracket out of some steel stock to provide a little clearance, and something to route the primary wire to. I mounted it to the inner fender with a rivnut, and bent the top into a hook for a zip tie.



So there you have it. It is very much the story of the old woman who swallowed a fly, starting with a dual battery system. Many a time since heading down this path I considered going back to the open element, but now that I've got it dialed in I'm pretty happy with it. Seems to be clean dry air available in the cowl; I once found a single pine needle in the air cleaner, but never any moisture, and have run it through some pretty serious storms.