Contructing the Rack
Many pictures related to this can be found at:
http://civic-ev.blogspot.com/2008/07/rear-trunk-battery-rack.html
Clean out the trunk and remove all the upholstery.
Cut two pieces of 1 1/2" square tubing (1/8" thick walls) 18" long. Drill 3/8" holes in each end, 5/8" in from the end, centered on the square face. Remove burrs from the drilled holes.
Fold down the rear seat of the Civic and find the plastic plug on either side just behind the rear seat in the trunk floor. Draw a horizontal line on the trunk floor (perpendicular to the length of the car) centered on these two plastic plugs. Then draw another line parallel line to the first, but 1 1/4" towards the back end of the car.
Just outside the plastic plugs, you should see a row of spot welds under the paint. Draw a line "connecting the dots" of all these spot welds. Mark where the spot-weld line and the second parallel line above intersect. Center-punch a point 3/16" directly toward the center of the car on each side of the trunk and drill 3/8" holes at the center-punched points.
You're going to align the two pieces of square tubing with the spot-weld line that you just drew. You'll notice that there is a manufacturing bulge in the trunk floor on each side that interferes with the flatness of the floor along this spot-weld line. Use a heavy hammer to pound it flat.
Line up the hole in one end of the square tubing with the 3/8" hole you just drilled and drop a 3/8"-16 x 2 1/2" bolt down through this hole.
Find the line of spot welds near the rear end of the trunk and draw a line "connecting the dots" through them on both sides of the car. Draw a parallel line to each of these lines 3/16" in towards the center of the car.
Rotate the rear-ward end of the square tubing until you can look through the rear-most hole and see the second parallel line next to the spot-weld line. Mark the center of the hole and drill a 3/8" hole here. Drop a 3/8"-16 x 2 1/2" bolt down through the square tubing and through the newly drilled holes in the floor. Repeat for the other side of the car
Cap off the bottom of the four 3/8" bolts with with a washer and nylock nut.
Cut two pieces of 1 1/2" angle iron (1/8" thick) 36" long. For each piece, drill a 5/16" hole 1/2" in from the end and 5/8" in from the outside vertical wall of the angle iron for the battery hold-downs.
For one piece, drill a 3/8" hole in 3 3/8" from each end, centered on the angle iron. Place this piece near the forward-most portion of the trunk with its inside vertical edge lined up with the seam on the chassis wall in front of the shock towers. Center the piece left to right between the shock towers. With a scratch awl or fine-tipped permanent marker, mark through the 3/8" holes onto the piece of square tubing. Move the angle iron away, center-punch the markings and drill 3/8" holes there. Replace the angle iron in it's original position and drop in 3/8"-16 x 3/4" bolts to hold it in place.
For the second angle iron piece, drill a 3/8" hole in 2 1/2" from each end, centered on the angle-iron face. Place this second piece on the square tubing so that the inside distance between the two angle-iron pieces is 13 1/8". Make sure the two angle-iron pieces are parallel and centered left-to-right. Mark through the 3/8" holes down on to the square tubing. As before, remove the second angle-iron piece, drill the marked 3/8" holes, replace the angle-iron and drop 3/8"-16 x 3/4" bolts in the holes.
Cut a 3/16" piece of plywood 34" x 13" in dimensions. Paint the tops of the 3/8" bolt heads for the two pieces of angle iron with a permanent marker. Lightly place the plywood between the pieces of angle iron, making sure it is centered left-to-right. Use a small hammer to imprint the painted bolt heads on the underside of the plywood. Remove the plywood and drill out where the bolt heads were imprinted with a 3/4" spade bit.
Dis-assemble everything and put the square tubing and angle iron aside for powder-coating.
Installation after Powder-Coating
Re-install the two square tubing pieces by dropping in the 3/8"-16 x 2 1/2" bolts. Do not yet add the nuts and washers for these.
Put the two angle-iron pieces back on and drop in the 3/8"-16 x 3/4" bolts. You should now have four "corners," each with a 2 1/2" bolt and a 3/4" bolt. For each corner, pull out the 2 1/2" bolt and pull out the 3/4" bolt. Lightly tape a 3/8" nylock nut to an open-end wrench and fish it through the end of the square tube. Drop in the 3/4" bolt for that corner into the nylock nut and tighten it. Pull out the open-end wrench, drop in the 2 1/2" bolt. Repeat for the remaining three corners. Finish off by capping off the 2 1/2" bolts with washers and nylock nuts underneath the car.
Drop in the 34" x 13" plywood you cut earlier.
Licensed under the TAPR Open Hardware License (www.tapr.org/OHL)
Copyright 2008 Tim Kutscha