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brucepick · 04-02-2018, 11:58 AM

I'm starting at the front. Made some progress today.

My car has one of Scott's aluminum front belly pans. Like the oem panels, it attaches to the oem support bracket at its rear, about even with the front wheels' centers. My first sub-project is to build a section beginning where Scott's panel ends.

Here's a drawing showing a cross section of the rear portion of the aluminum panel (blue) with the oem support bracket (black). I added a 1" x 1/8" x 25" backing strip going across the top side of the panel. That will give the fasteners for the coroplast something more substantial to anchor to.

I considered resting the coroplast on top of the bracket. That is, the horizontal cross member that supports the trailing edge of the forward belly pan. But the up and down features in the aftermarket panel and also the bracket, aren't ideal for aerodynamics - so I plan to hang the new section to the underside of the aluminum instead. So covering up those irregularities.

I will use rubber well nuts to secure the leading edge of the coroplast to the underside of the aluminum panel. They work a bit like expanding wall anchors. Tightening a screw into them forces them to expand, so they won't pull out. The screw is removable and so is the well nut. Mine take #10x32 screws, need a 3/8" hole.

I figured the aluminum belly pan by itself might not be enough for the well nuts so I added the 1/8" backing strip. I used seven 1/8" diameter pop rivets to secure the 1/8" bar stock backing strip above the panel. Rivets inserted from the bottom side.

Here's a drawing showing a compressed well nut with washer and screw, and a pop rivet. Shows the belly pan (blue) and the 1/8" backing piece. I omitted the layer of coroplast that will go between the well nut and the washer, sorry.

Here's a photo of a 3/8" hole with well nut partially inserted. The panel is upside down here. The well nuts and their screws will be inserted from the underside when assembling it.

Here's a photo, panel still upside down, with well nut inserted and a screw + some washers tightened into it. All stainless because I hate when fasteners get rusty. Tightening the screw squishes the well nut so it expands; it won't pull out.

04-02-2018, 11:58 AM	#4 (permalink)
brucepick OCD Master EcoModder Join Date: Dec 2007 Location: Eastern CT, USA Posts: 1,936 Outasight - '00 Honda Insight Team Honda Gen-1 Insights 90 day: 54.18 mpg (US) Thanks: 431 Thanked 394 Times in 262 Posts	I'm starting at the front. Made some progress today. My car has one of Scott's aluminum front belly pans. Like the oem panels, it attaches to the oem support bracket at its rear, about even with the front wheels' centers. My first sub-project is to build a section beginning where Scott's panel ends. Here's a drawing showing a cross section of the rear portion of the aluminum panel (blue) with the oem support bracket (black). I added a 1" x 1/8" x 25" backing strip going across the top side of the panel. That will give the fasteners for the coroplast something more substantial to anchor to. I considered resting the coroplast on top of the bracket. That is, the horizontal cross member that supports the trailing edge of the forward belly pan. But the up and down features in the aftermarket panel and also the bracket, aren't ideal for aerodynamics - so I plan to hang the new section to the underside of the aluminum instead. So covering up those irregularities. I will use rubber well nuts to secure the leading edge of the coroplast to the underside of the aluminum panel. They work a bit like expanding wall anchors. Tightening a screw into them forces them to expand, so they won't pull out. The screw is removable and so is the well nut. Mine take #10x32 screws, need a 3/8" hole. I figured the aluminum belly pan by itself might not be enough for the well nuts so I added the 1/8" backing strip. I used seven 1/8" diameter pop rivets to secure the 1/8" bar stock backing strip above the panel. Rivets inserted from the bottom side. Here's a drawing showing a compressed well nut with washer and screw, and a pop rivet. Shows the belly pan (blue) and the 1/8" backing piece. I omitted the layer of coroplast that will go between the well nut and the washer, sorry. Here's a photo of a 3/8" hole with well nut partially inserted. The panel is upside down here. The well nuts and their screws will be inserted from the underside when assembling it. Here's a photo, panel still upside down, with well nut inserted and a screw + some washers tightened into it. All stainless because I hate when fasteners get rusty. Tightening the screw squishes the well nut so it expands; it won't pull out. Last edited by brucepick; 04-02-2018 at 10:58 PM..