Old bed liner for belly pan - Fuel Economy, Hypermiling, EcoModding News and Forum

ngrimm · 04-10-2011, 03:55 PM

For my black Bronco II 4x4 I would like to add a front belly pan but haven't found anything cheap or strong enough to cut up. Then I noticed there are lots of used plastic (abs?) bed liners on CL for $50 and up. There would be a lot of material left over maybe even for an air dam etc. Btw, I'm not expecting miracles for mileage but since I have ordered an Mpguiino or whatever it's called I can do some ABA tests. All of the bed liners I have seen have ribs on the bottom so I was wondering if that would be bad for use as a belly pan. Thank you.

slowmover · 04-11-2011, 01:53 AM

I think it's a great idea! Glad you thought of it.

ngrimm · 04-11-2011, 01:30 PM

Thank you. I think I'll give it a try. The underside of this Bronco looks pretty "unclean" to me due to the ifs. The front differential is nearly a flat surface hanging down 12" below the frame. At least the old straight axle 4x4's had a rounded housing. Would having a belly pan that starts at the existing bumper/spoiler and angles down to cover the axle work instead of adding an air dam? I've been reading all I can on this forum for about a year but don't recall seeing that discussed.

Bill in Houston · 04-11-2011, 07:46 PM

Seems like a good idea to me. Easy to cut and drill, but still stiff enough. And if you get really excited you can shape it some with a heat gun.

Flipper_1938 · 04-12-2011, 02:50 PM

I bought a bedliner off of ebay for $.01 ...and it was local pick-up!

COcyclist · 04-13-2011, 01:12 AM

Quote:

Originally Posted by ngrimm

Thank you. I think I'll give it a try. The underside of this Bronco looks pretty "unclean" to me due to the ifs(diffs?). The front differential is nearly a flat surface hanging down 12" below the frame. At least the old straight axle 4x4's had a rounded housing. Would having a belly pan that starts at the existing bumper/spoiler and angles down to cover the axle work instead of adding an air dam? I've been reading all I can on this forum for about a year but don't recall seeing that discussed.

If you are suggesting using the bedliner from below the bumper angled downward, it sounds like a better design for an off-road skid plate than for improving aerodynamics. Big Dave on this site has had good success with a big air dam on a full size truck. I really do like the idea of repurposing a discarded bedliner as belly pan material. Could you try an airdam and a lowered belly pan below the differentials like BamZipPow's Toyota?

ngrimm · 04-14-2011, 03:01 AM

Thank you to all for your comments. I hauled the free bed liner home today. Also I received my MpGuino fuel mileage gauge a couple days ago and got it hooked up today. It is working great! Still need to build a case for it and calibrate it a little better but the fuel mileage it is reporting seems pretty close to what I had determined previously. The front bumper is 18" from the ground and the front differential is 9" from the the ground. What I am thinking about is using the front part of the bed liner as an air dam and letting the lower part serve as the belly pan. My two concerns are: 1. Is the curved transition from the air dam to the belly pan a bad thing? 2. Is having the air dam and pan 9" from the ground too high to be effective? Incidentally the bed liner is the same width as the front bumper so it can wrap around the sided but the tires will stick out about 3" on each side. I'll try to get some pics tomorrow before I start wacking it up.

War_Wagon · 04-14-2011, 04:24 AM

That is a really good idea! If there is anyone in the Vancouver BC area that wants to try it, I know where there are a bunch of old bedliners that could probably be had for free. PM me if you want to try this out.

COcyclist · 04-14-2011, 11:06 AM

Quote:

Originally Posted by ngrimm

My two concerns are: 1. Is the curved transition from the air dam to the belly pan a bad thing? 2. Is having the air dam and pan 9" from the ground too high to be effective? Incidentally the bed liner is the same width as the front bumper so it can wrap around the sided but the tires will stick out about 3" on each side. I'll try to get some pics tomorrow before I start wacking it up.

I assume your plan is to make the vertical cab-side part of the bed liner serve as the air dam? If so, the curve would be minimal, not enough to worry about. Great idea!! As for ground clearance, if the bottom is smooth, more can be a good thing. Think Aptera or Sunracer.

ngrimm · 04-15-2011, 12:55 AM

Here is what I've been doing. As mentioned above, the air dam and belly pan are one piece. The dam is 10 inches tall leaving 9 inches of ground clearance in the front. For now I think I'll cut the belly pan off about a foot behind the front tires. After the pics I used screws and washers to fasten the new air dam to the exiting small one. Not sure if I should try to angle the bottom of the dam toward the rear of the Bronco or leave it vertical. The whole thing should be easy to remove.