Monday, February 2, 2015

Seat Belt Switch

Chrissy told me she was tired of hitting her head on the roof whenever we hit big bumps in the Miata, so she wanted four-point harness for the passenger seat, like the one on the driver side.  I started looking for a racing seat and a harness.  I got super lucky with the harness, and found a fellow on Craigslist selling a pair of harnesses nearby in Redondo Beach.  I only needed one, but his price for two was what I expected to pay for one.  Plus, they were black, and it would be nice to have a matching set in the Miata.  I was never a big fan of the blue one the car came with.

I planned to wait until I found a racing seat for sufficiently little money, but I decided to see how the harness felt going around the stock seat.  It seemed reasonable, so I decided to commit.  I unbolted the seat and started removing the stock seat belt components.  This big bar was first to go.  It tied the buckle into a solid point on the chassis.

With just two bolts on the bottom and some appropriate wrapping around the roll bar, the harness was installed.

The stock seat belt was proving a little difficult to remove, so this is all I was able to get out the first day.

One of the problems I was having was with this bolt.  On the driver side, it appeared it screwed into a captive nut, but on this side, it just spun, and there was absolutely no way to hold the nut on the other end.  I messed with it for quite a while, but finally gave up.

My other problem was the retractor was trapped in its little nook by the roll bar.  I didn't want to unbolt the roll bar, so I had to get creative.

The answer to both problems ended up being the same:  Sawzall.

Look how clean it is now!

There was a significant amount of struggling to get the retractor out, but I got it.  The roll bar got a little scuffed up, but it will still do its job.

Here's the rest of what came out.

Normally, it doesn't take this many tools to remove a seat belt.

At this point, I thought I was done, but after one drive with the new belt, it was clear something needed to change. It was slipping off Chrissy's shoulders, which is a big problem.  I again thought of a racing seat, but my inner cheapskate tried to think of a cheaper solution.  All I needed from a racing seat was the holes for the belts to go through.  Why not just add holes the the existing seat?  They even have a basic template where the speakers used to be.
We both sat in the seat and marked where the tops of our shoulders sat.

Then I started cutting.

 And some test fitting.  It looked like it just might work.

When I was happy with the holes, I did some quality tape work.

And installed it in the car.  I didn't take pictures, but the back is similarly taped.
We haven't done much testing yet, but this seems to work perfectly.  I will report back if there are any issues.  I'm a little surprised I haven't seen this done before.  A little searching shows people are really paranoid about four-point harnesses.  I'm all for safety, but they seem a bit crazy.

The final task was to replace the driver side, which looks much better with the black harness.
Weight Removed:  6 lbs
Weight Reinstalled:  2 lbs, 7 oz

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