Spec E46 Build Part II: Blocking Plates

After completely gutting the interior of the Spec E46, I began to prep it for its future life as a race car.

The gaping hole in the dash that once held the HVAC unit needed a blocking plate. I sourced some scrap aluminum from the local metal recycler just for this. A piece of card stock was used as a template. I was able to reuse to of the upper original mounting nut plates, and the remainder of the plate was riveted in place.

I used some quick setting black RTV between the panel and firewall to ensure it was water proof.

I also ditched the stock spare tire mounting post. This piece isn’t even welded into the body, it is rotated into place and held in with a heavy dose of seam sealer. Grind off the seam sealer with a wire wheel and the post just twists out.

I used the same scrap aluminum to create another blocking plate. I riveted in from the bottom, sealed in place with the same RTV I used on the HVAC panel.

By this point I had already removed the engine, which allowed for easier access to the front of the firewall. With the AC and heater gone there were a couple of more unneeded holes in the firewall. For these I used sheet steel rather than aluminum so that I could weld them in place. I used card stock again to make templates. Once welded in I went over it with a light coat of seam sealer.

I also created a block off plate for the engine side of the firewall. While not necessary at all, I think it will certainly help keep the cavity between the inner and outer firewall clear of debris and fluids, plus it just looks better.

I used a thicker sheet of scrap aluminum, held in place by three bolts anchored to the sheet metal with nutserts. I had to trim the panel around the center wiper arm, but overall the panel is as tight a fit as possible.

Finally I decided to make some block off plates for the large openings in the side walls beside the rear seat area. These panels are almost entirely cosmetic but do help to keep debris out of the inner panel. I used much thinner aluminum sheet, riveted in place and sealed up with seam sealer.