Short Ram Airbox
If you currently have a short ram intake, you are feeding your engine hot air from the engine bay. The higher the temperature of the air, the fewer oxygen molecules contained in each unit volume. The less oxygen your engine takes in, the less fuel can be added and the less power you can make. The goal of this modification is to prevent the intake from sucking in hot air from the engine bay and provide cool air from the front bumper.
The first step for this project is to come up with measurements for the box. Start by taking a tape measure and make some rough measurements of the engine bay to decide the length and width of the box. Once you have an idea of what the box will look like, you need to come up with depth measurments [bottom of box to hood]. To do this, get some soft modeling clay and roll small pieces into columns about 3" long. You stick the clay columns to strategic places in the engine bay where you want the top of the box to seal against the hood. With the clay columns in place, shut and latch the hood. Then pop the hood and look at the clay pieces. They will be squished down to the correct height for the top of the airbox. Once you've got all the rough measurements for the box, you are ready to make a cardboard mock-up of it. Cut up thin cardboard to the rough measurements you made earlier. Then assemble the cardboard to make an airbox. Tape it all together and stick it in the engine bay. Then you can cut and tape it to make it fit perfectly. Once you have it pretty close, pull out the cardboard copy and use it to make the final version. You can use sheets of steel, aluminum, polypropylene, or lexan. Use a pop-rivet gun to attach the pieces together. Don't be afraid to rivet every inch, if needed.
Cut out a hole for the intake tube to enter the box. You should also cut a 4" hole in the bottom of the box to attach the dryer duct to. To cut the 4" hole, draw a 4" circle on the bottom of the "box" and mark the center of the circle. Then cut from the center of the circle straight out to the edge of the circle, cutting it up to look like a pie. Bend the "pie slices" downward out of the box to make "claws". These "claws" can be bent to grab the inside of the 4" dryer duct.
You can bend the tops of the box sides to form a lip. If you split rubber hose down its length, you can thread it over the lip to form a seal. Alternatively, you can use proper automotive-style weather stripping that will clip onto the top of the box sides. Either way, you need to seal the top of the box against the hood. If you paint the box, use the appropriate paint. Epoxy works well on steel and aluminum. Flexible paints that fuse with plastic work well with polypropylene and lexan.
You want to attach one end of the 4" dryer ducting to the front bumper. You can bend it to match the shape of the brake scoop and screw it to the bumper. If you want to seal the edges, clean the brake scoop with alcohol and seal it with electrical tape. Run the dryer duct up to the airbox. Use the bent "claws" on the hole in the airbox to grab the inside of the dryer duct. If you are using polypropylene or lexan, the claws will not grab well. You can use galvanized steel, copper, or brass wire to sew the claws to the dryer duct. Now everything is installed and ready to test. The next step is to trouble shoot the whole thing for rattles. Most rattles can be solved with some electrical tape.
Contributed by Corbin
Cars Modifications Power BPU Short Ram Airbox
Last modified on 2009-01-11 19:04:47