Friday, October 2, 2020

Modernizing the Stereo, Part 2 - Mounting the Distribution Block

So as mentioned in my previous post, the new dsp amp had arrived, along with all of the professional grade OFC wiring, and accessories such as the fuse holder and a fused distribution block (power in/out from battery, and then split into leads for two amps - one for immediate install and the other for a future upgrade as needed).

I had decided that I would mount the dsp amp in the space next to the battery, but this meant no space to install the distribution block in the same space (having placed the dsp amp in the space just to make sure it fit). 

Looking around, I realized my choice was either to mount the block below in the tire well, OR in the space where the jack used to be (no jack because no spare due to the R35 calipers and rotors).  While it was tempting to mount in the tire well because it would call for less wiring, I was concerned that there was nothing to solidly mount the distribution block to. And I'm not about to drill holes into my car. Ever.

With both the battery and the amp nearby, theoretically this is a good spot to locate the fused distribution block.
But no existing holes or bolts to attach to.

On the other hand, in this space:

Green arrows point to potential existing mounting points

I saw that there were two bolts with threads still showing (used to attached the bumper?) as well as two bolts on the vertical wall where the jack holder was attached. 

Initially, I was hoping to squeeze the distribution block into the jack holder, but it didn't work. So, I ended up removing it.
It's just not secure like this.

So now the challenge was to create a proper mount for the distribution block that would be large enough to solidly attach the block (last thing I need is a bump in the road to cause the block to fall and somehow short out). Given what I had seen the pros do, I ordered a large piece of ABS plastic, with the intent to use it mount both the block and the amp.

And then after some rough measurements, cut out a rectangular shape, drilled two holes to match up to the bolt holes used to attach the jack holder, and then used a heat gun to bend along the line where the ABS extended past the steel wall.
I also bent the ABS up in a lip shape at the end

And drilled two holes in the lip to clear the bumper bolts

I was pretty lucky, my measurements were spot on so this is how the ABS mount looked installed:

After I confirmed the fit, I uninstalled and it was time to attach the distribution block and wire it up.
So maybe here? Shifted to the right (top) side as
we would need clearance for cables on the bottom

Close up, you can see that the left side is bridged for the ground wire coming into the center  
while the right side has a fuse for the power line between the center and the output terminal

This is a 1/0 AWG cable - for power and coming straight from the positive battery terminal so it's red - and you can see I have added another fuse for the remaining positive terminal. 

So the red is positive, and the black negative. Center wires are 1/0 AWG while the output red and black wires in foreground (that will connect to the amp) are 4 AWG

And here it is, installed. Fits perfectly, is solidly mounted,
and all the cables clear the felt trunk liner (I tested to make sure)

Note I've left one side of the block free for an amp for a future subwoofer, if I decided to go that route -  and then temporarily attached the cables to see how to best route them.  

Next - I'll show you how I created the mount for the dsp amp. See you soon!

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