I started using a piece of cardboard between my battery and the intake a few years ago, and it seemed to gave me about a 2 miles per gallon increase. (Though after building this, I received criticism that this will not help with gas mileage, but will help with performance!)
Now it was time for me to relocate my battery so now I have to make a Hot air block from scratch.
I made this one from metal, and I expect better performance than my cardboard version.
This is the finished hot air block and my new battery box
These are the few sheets of sheet metal I have.
They are about 22 gauge steel. (With this gauge I am using, the metal is sometimes one size smaller than measured)
I removed the stock battery tray.
My girlfriend made a template for me.
Its a nice fit on this side.
And a very tight fit on this side.
Its a little too tight on the headlight housing.
The height for the hood looks good too.
This is where the upper rear mount will bolt to.
The center will be the bottom mount.
And just above the passenger headlight will be the front top mount.
This is the cardboard template after a few trims where the headlight housing is.
I placed the cardboard template on my sheet metal and put my battery on top to hold it in place.
Then I traced around the template onto the sheet metal.
I freehand cut this with my plasma cutter. You can also use a jig saw, or many other cutting tools.
I marked off another spot that should be cut by the headlight housing.
Just a quick snip with my tin snips, and the headlight housing should be clear.
I also cut out a rounded section for the wires to pass through safely.
After these 2 pieces were cut, I used my angle grinder to smooth out my cuts.
Its been a lot of metal working lately, I am also building my own battery box.
I now marked off another place I wanted to cut, by the headlight housing.
I test fit it using welding magnets, and made sure my cut would be in the right place.
And if there were any other cuts needed.
Everything else looks good but the area by the headlight.
While it was held up with the magnets, my girlfriend helped make the 3 mounts.
She even labeled them for me.
I traced them onto the sheet metal and plasma cut them out.
Then I used my bench grinder to round them over, and remove the rough edges.
I used the magnets to hold the air block in place in the car, with the brackets bolted in place, and tac welded them on.
Then after removing it from the car, I welded them up completely.
It bolts in and look good.
After I removed it from the car, I cut out the part by the headlight, and ground it smooth.
Now to sand everything and prep for paint.
I used a spray can to tilt the air block up and paint one side. One coat and it has a great mirror surface.
This is after the first 3 coats of paint.
Now everything has 5 coats of spray paint. This should prevent pealing, chipping, and cracks.
It has a good reflection.
I bought some door edge guard to put on my hot air block. This will protect the wires from scraping the metal.
It looks great!
Works great with the battery mount I fabricated.
It sits just above the battery box, right behind the battery.
I do not use my high beams much, but if I ever need to replace it, the hot air block is only 3 bolts to remove.