D1 subwoofer build in right rear pocket.

I previously upgraded the rear door woofers using the original housing, did some Dremel surgery, installed some small woofers, and a new amp as I one of the first things I did was replace radio, remove the factory amp in the kick panel, ran 2 runs of 16/4 speaker wire from behind the radio to the kick panel, and bypassed the amp. I then went ahead and removed the factory sub amplifier, ran new speaker wire from the new installed amp under the rear bench to the rear door where the subwoofer resides, upgraded the woofers as they were bad as the surrounding material was all gone. It works great, after two years of that upgrade I decided I want more base and what better way than to build a custom fit fiberglass backed enclosure.

I began by removing the far right 3rd row seat as my truck was equipped with it. I believe it should be the same for D1's without the 3rd row seat and have a cubby hole instead.

Once the seat was removed with all the brackets I began to tape off all the open areas with duct tape ex.. rear light cover door removed then duct tape over, openings for the seat bracket, and other holes in the panel you may encounter, then I used blue painters tape, and began taping the floor carpet area, and continue to tape in a upwards pattern as to shingle the layers of painters tape so you don't run into seepage from the resin pooling in the bottom or entering where you don't want it to end up. Then you will want to spray glue over the painters tape and apply aluminum foil in the same manner from bottom up and layering each piece, then again another layer of blue painters tape, it may seem as overkill on the layers but there is always a reason behind it. Now use any automotive paste wax apply it generously to the tape starting from the top and work your way down so you don't accidently disturb and lift the blue tape, there is no need to buff or remove the wax as this will be your mold releasing agent, but if you want to repeat the process of applying the wax go ahead and do so it doesn't hurt to.

 

Now for the fun stuff make sure to have all your materials available and a helping hand so you can get to the next step and make sure to cover your interior when working with fiberglass as to not drip or smear resin onto your interior you will never get it out of the carpet if the accident were to happen.
The materials needed can all be picket up from your local hardware store you will need the following:
1 gallon or 118 oz. of fiberglass polyester resin, 1 bag of 8 sq. ft. of fiberglass cloth, 2 bags of 8 sq. ft. of fiberglass mat, disposable nitrile gloves for you and your helper, 16 oz. paper cups (IMPORTANT DO NOT USE PLASTIC CUPS), 2 2" chip brush (CUT THE BRUSH FIBERS TO HALF LENGTH), blue painters tape, aluminum foil, spray glue, plastic cover (FOR COVERING INTERIOR), wax, old plastic medicine syringe or small disposable measuring cup that measures cc's, and 2 paint stirring sticks.

ALWAYS READ ANDN FOLLOW ALL SAFETY INSTRUCTIONS FROM THE MANUFACTURER, FOLLOW ALL DIRECTIONS OF WORKING WITH ANY CHEMICALS, AND WORK IN PLENTY OF VENTILATION AS THIS STUFF WILL SMELL.

Put on your gloves and let the fun begin. Apply 12 oz. of Resin or apply resin to the paper cup 3/4 full. Depending in your area temperature the hotter it is the less catalyst you apply, the colder it is the little more you will need to apply. Also precut your fiberglass cloth and mat to some squares 6" x 6", some strips 6" x 12", and less of strips of 4" x 2", before getting started with mixing resin this will make your project less stressful. Both of you will begin by mixing the first cup of resin, then one of you will work in the back of the rover applying resin to the waxed and taped surface working from the bottom up and begin applying the small 6" x 6" strips of fiberglass cloth on the bottom working your way up and always overlapping the edges so you will create strength to the edges as you apply your layers of fiberglass cloth, you will use all the 3 different sizes of cloth that you previously cut to complete the covering of the entire surface. Once you have laid a complete layer of fiberglass cloth you will begin at the bottom and work your way up by using the fiberglass mat also make sure to overlap all edges. Once that is complete clean up the area and let it dry. it is a good idea to have a Non-Contact Infrared Thermometer to see the progress as it cures you can experience temperature start at room temperature and can reach 200 degrees as it begins to kick off (EXOTHERM). Make sure to keep a bucket of water just incase a mixing cup gets to hot you can always dunk it in the bucket of water and wait for it to set.

NEVER THROWAWAY RESIN OR RESIN MIXED CUPS IN ANY TRASH OR AREA THAT MAY CATCH ON FIRE UNTILL THE CUPS ARE CURED, COOLED, AND NO LONGER IN THE EXOTHER PROCESS).

It was 76 degrees here today so I applied 3 cc's of catalyst hardener to the 3/4 cup full of resin and began mixing by stirring with a paint stick. Mix the resin with the hardener thoroughly so the resin cures or it may not set correctly and be sticky. As you apply a coat of resin to the taped and waxed surface. You can add 5 cc but if you notice that the cup of resin begins to gel before you have consumed the cup cut back on the catalyst (HARDENER) or make only 1/2 a cup of resin to 2 cc's depending on the temperature in your area.

 

Just finished up cutting the MDF panels, attached it to the trimmed out fiberglass shell, sealed the internal parts of the box, and installed the 8" Kicker DVC woofer. It sounds awesome, next is to remove the existing woofer setup from the rear door and cut a new rear door panel to have a solid surface with no woofer hole in the new panel this will be used as a template for the future drop down table build.


Doubled 1/2" MDF for a rigid surface for the subwoofer and to allow the subwoofer to be recessed for a flush look.



Sub installed and box sealed, it sounds awsome, just need to do the finish work and wrap it in vinyl to match existing interior.

 

Looks good! I might have opted for a 10" but thats me!

 

Thanks Saturnine,
I really wanted to go with a 12" sub but due to the gas filler body bump out running down the center I had to move the woofer to either side to clear the magnet of the woofer, other option is to bump out forward to give more depth to the enclosure, or last cut out the back of the interior panel and bolt the subwoofer enclosure directly to the body.

I am now working on the front lower door panels that will replace the lower door cards, I have them roughly built, installed, but I have not taken any pictures yet, as soon as I do I will upload them.