7" retrofit (GDAA WRX)

[Fstrsn]

Ah, ok, nevermind then. . .

Hmmm. . .

Is it possible to fabricate some clips that attach to the fog light opening and have it snap in?

[satrya]

Is it possible to fabricate some clips that attach to the fog light opening and have it snap in?

Yes, that would be ideal. In my older version, I completely mimicked how an optional oem foglight cover (which completely obscures the foglights and the entire recessed area of the bumper cover where the foglights sit) mount. The top one takes advantage of pre existing slots like so:


In which I took advantage by mounting two metal tabs on the plastic trim cover like so:


So that the trim piece slots in on the top side:


And the bottom sees an extended bracket from one of the foglight's mounting point:


So that the trim piece can be held together by the 2 tabs above and this lone screw:


I could do the same with the new trim piece, and figure out a way not to have those 4 screws (that secure the metal tabs) be visible. That would be a minor modification to the trim piece version I made 10 years ago (pictures above).

But in the spirit of making things more complicated, I wanted to extend the reach of the foglight trim piece. Where staying within the confines of the bumper cover recess like before permitted a flat trim piece, extending the reach beyond it would require a curved trim piece. I thought this would make it more challenging. The two pictures below show the difference in how far recessed the older one is, and how much more curved and wider the new one is.



This extends the extreme edges of the trim beyond the reach of the 2 slots previously used for the 2 tabs on top and the screw on the bottom.

To make matters worse, I wanted to have an inlet and outlet to allow some air to cool the metal shell of my DIY foglight housing, since the foglights run on 55W halogen bulbs. That means the edges better be secured tight enough lest it fly off at speed.

Also, I don't want to make permanent holes on the bumper cover. Any change has to be reversible to OEM state. So, no fasteners mounted on the bumper cover.

[satrya]

Aluminum bar for securing the top edge

Yet another experiment.

I'm going to see if this can work to both maintain the proper curve on the black plastic piece as it hugs the corner of the bumper cover, and at the same time hold it together so it doesn't get blown by the air flowing behind it (to cool the foglight housing).

I took a random piece of transparent plastic (on the left edge of the picture below), and traced it along the corner of the bumper cover (with the green marker). I then transferred that "template" onto a piece of an aluminum L bracket. Most of the bottom of the "L" is trimmed off, leaving 3 tabs like so. The 2 middle tabs will be used to attach it into the foglight opening. The fork like tab on the far right will be used to hook itself to one of the openings on the side of the bumper cover (more on this later).


The aluminum bar was carefully bent to match the bumper cover's corner curvature. Tentatively, it will sit like this relative to the black plastic piece:


I hope the top part of the black plastic piece can be secured by this aluminum bar, which in turn needs to be rigidly (but not irreversibly removable) secured to the bumper cover.

[satrya]

How the aluminum bar is secured on the side

Since the bumper cover is made of plastic, I made this scratch shield from sheet aluminum, bent around to form a removable clip that can protect the bumper cover.


The scratch shield installs onto the topmost of the 3 vents on the side of the bumper cover (see upper left of the picture). The aluminum bar sits like this relative to the bumper cover:


The fork goes into the vent that has the scratch shield installed like so:


And the aluminum bar would "wrap" around the corner like so:


The bumper cover's contour (both in the left-to-right curvature and up-to-down curvature sense) along the direction of the aluminum bar is quite more complex than I had hoped for, so there are a lot of potential areas where the black plastic piece may not "hug" the contour as easily.

We'll see.

[Fstrsn]

Sound's like you're on the right track. Although I don't know how secure that spring clip is going to be.

[satrya]

Sound's like you're on the right track. Although I don't know how secure that spring clip is going to be.

I don't either. The spring clip is just there so that the aluminum bar's fork doesn't exert too much of a concentrated pressure to the painted surface of the bumper cover.

As far as I can see, the bigger deal in terms of secure mounting is the inlet side (close to the centerline of the car).

[satrya]

Vertical load support

Now to build a vertical load support for the aluminum bar as its "fork tip" rests inside a vent on the corner of the bumper cover. I decided to use spare 2x4 material, cut and filed to shape.


The vent opening is somewhat curved, and after some back and forth filing and measuring, the piece looks like this:

[satrya]

The wooden piece fits in by interference fit (think of a wine cork), where it is stiff enough to support the vertical load of the aluminum bar and the black plastic fog trim piece on that side, but soft enough to be able to wedge-fit itself into the vent opening. The wooden piece leaves a bit of a gap on top.


The angle where the picture above was taken makes it look like the wooden block is too small, but the apparent clearance on the side is because the inner vent shape of the bumper cover tapers in. At this point, the wooden piece fits snugly in.

[satrya]

Test fit of wooden piece + aluminum bar

The aluminum bar's fork tip goes in like so:


And then, the aluminum bar is turned this way onwards to the bumper cover surface:

[satrya]

Marking the backside of the wooden pieces so I don't mix them up or mount them incorrectly.

[satrya]

Now to figure out how to attach the middle portion.


.. so that the 2 slots at the top of the oem bumper cover can be used to secure the aluminum bar.


But it needs to be a latching mechanism instead of being bolted on, as that location will be completely obscured when the black plastic trim piece is installed.

[satrya]

Replicating the aluminum bar

While thinking of ideas to make use of the 2 slots in the bumper cover, might as well do something else.

Replicating the aluminum bar for the other side;

Raw material:


Duplicate copy for the driver's side, after cut to shape, and edges filed off.


Going back and forth to place it in front of the bumper cover to match the curvature. The result should be a mirror copy of the passenger side's.

[satrya]

Painted the wooden "cork" as close to body panel paint as possible. I wanted to minimize the chance of the cork from rotting over time, and if it marrs the body panel paint, at least it does so with a similar color.

[satrya]

Cutting a template for 2 tabs that will hold the aluminum bar in place, but will still make the bar easy to remove.


It goes in like so..


Since the location of the slots for the 2 tabs are about 1" deeper into the bumper cover's recess than the location of the aluminum bar, the material that contains the tabs will need to make at least one 90-degree-bend to join the aluminum bar. Since the thickness of the tab is limited by the thickness of the slots, I didn't want to use a single sheet metal without reinforcement. Instead, I'm going to see if a rectangular bar can be used as reinforcement.

Cutting an aluminum rectangular bar to the proper length (that spans the 2 tabs):


Due to the curvature of the "ceiling" in the bumper cover recess, a bit on the left side needs to be trimmed off as marked above.

Trimmed and filed to remove burrs:


Now the rectangular bar can keep the proper roll orientation of the aluminum bar (not shown):

[satrya]

Slight change in direction

It looks like the aluminum bar wouldn't be able to exert enough bending moment onto the extreme ends of the black plastic. Air pressure build up on the front side of the bumper cover might pry the plastic off altogether.


Time to consider a smaller piece, but unlike the first version, is not 100% flat. In order not to make irreversible mistakes trimming the plastic piece, as usual, a paper mache copy is used. Here it is after trimming it off considerably so one edge doesn't go over the edge of the bumper cover:


Contrast this to the initial plan of making it wrap around the edge: