I finally got around to making my front belly pan on my truck. I've been looking into this for a while now, particularly in an effort to help my warm-up times as the weather is getting colder. I know there should be an aero benefit as well. Now that the temperatures here are getting down below freezing, it's really taking my engine an incredibly long time to warm up, especially now that I'm using EOC P&G so much now. One morning a few weeks ago I drove the entire way to work (25 miles) and just barely made it all the way up to 200 deg F. Most days it's been taking 14+ miles. And this is with the entire front grille block, an engine insulating blanket, and the cabin heater off the whole time.
Anyway, here are the construction pics. I used two strips of plywood to give me something to attached the sides and rear of the pan to. I screwed the front of the strips to the plastic air dam and zip-tied the back of the strips to pre-existing holes in the frame.
I then cut out the pan itself. I used a sheeting material called "Thermo-Ply" that I had lying around. It's a wood-based material, about 3/16" thick and semi-flexible. It's about 6 feet x 3.5 feet:
I then attached the pan with drywall screws:
I was going to stop there, but at then I added another smaller section to extend the pan back to the end of the engine compartment--back to where the transmission starts and the rear wheel wells end:
Eventually, I'd like to extend the pan all the way back, but this will have to do for now.
As far as results go, I've run it for a week now. Warm up times may have shortened by a mile or two, but it's kind of difficult to tell. The weather has been kind of wierd recently (temperature, rain, fog, etc), so I have'nt been able to get a good feel for how much it may have helped the FE. Also, I changed my transmission fluid over to some full synthetic at the same time.
Of course, the best part of the belly pan is that I made it entirely of scaps I had lying around. Can't beat a total cost of $0!