Old bed liner for belly pan

[slowmover]

I think this could wind up being a nice-looking aero piece (not that it matters in some respects); more factory-like. Re-purposing, and the benefit of appearing as-if factory-made from some angles. Way to go!!

[piers.singer]

Originally Posted by ngrimm

I cut the dam off two inches in height got it all fastened down with screws in the dam part and heavy plastic ties (rated at 175 lbs) for the belly pan part. Still need to add the chin. I used a sawsall and a small sabre saw to do all the cutting. A step bit worked really well for drilling the holes. So the pan bows down about 3 inches as it passes under the front diff and bows back up about the same distance once behind the diff. Should I have kept it at the same level after the diff?

The ideal, as far as I can understand the science, would be to have the pan level with the front dam until it passed behind the rear diff, after which it should gently slope up. Like the other chaps have said, the purpose of the air dam and splitter is to make a clean separation of the air-flow, so by introducing an angle at the front, you might well be messing it up.

Whether or not the difference is measurable, I don't know, but that's how I understand it. Anyone, please feel free to correct me.

[euromodder]

Originally Posted by ngrimm

So the pan bows down about 3 inches as it passes under the front diff and bows back up about the same distance once behind the diff. Should I have kept it at the same level after the diff?

As the belly pan is angling down to clear the differential, you could have kept the air dam at a length that clears the diff - as it gives the same frontal area.


If only the diff is sticking out underneath, you could look around for some streamlined shape / bulge that could cover it, then make a hole in the belly pan, and cover the hole and the diff with the streamlined shape.
That way, you'd be able to raise the belly pan back to horizontal, and only increase the frontal area right where the diff is, and not over the entire width of the truck.

[lunarhighway]

just a thought that popped into my head, but wouldn't a good compromise to streamline "stuff" (like a dif )portruding from the undertray be to build a boattail for it? some L brackets angled towards eachother might be a good idea... ok it's a detail and the effect might not be measurable, but on the other hand it seems like a simple thing to do that's practical (some cheap plastic L brackets that can be screwed to the undertray behind an inperfect portusion...

just a thought

[ngrimm]

I flipped the top part of the bedliner and trimmed the edge to make a serve as the "chin". It is hanging about an inch below the bottom of the belly pan. I left enough length to allow me to adjust it up and down temporarily. Probably look better if more was cut off.

[euromodder]

Originally Posted by ngrimm

I flipped the top part of the bedliner and trimmed the edge to make a serve as the "chin".

Inventive
That should do the job.

How does it look from the front ?
It'd be good if the air dam also shielded most of the wheels.

[aerohead]

Originally Posted by ngrimm

So would it be better to raise the air dam a few inches and let the belly pan bend downward under the diff? Also I think I can flip the top front section of the bed liner and use it as a small air dam chin or whatever it is called.

My pan angles down to the bottom of the axle allowing better ground clearance in front of it.Then shallow diffuser behind axle.
Note of caution.ABS is a thermo-formed plastic so you'll want good heat shielding near cat-converter/exhaust pipe/muffler or she might revert to pre-formed sheet,and in turn,buckling the pan.Ouch!

[ngrimm]

Here is the front view. Notice I covered the grill to see if that helps I imagine having tires exposed and also the body being open on the sides isn't helping much. Before I can do some ABA tests I need to get my MPGuino recalibrated since I just replaced the faulty fuel pressure regulator which was sucking into the intake. I modified a new one to make it adjustable so I could lower the pressure a little since it was running rich in open loop.

[aerohead]

Originally Posted by ngrimm

Here is the front view. Notice I covered the grill to see if that helps I imagine having tires exposed and also the body being open on the sides isn't helping much. Before I can do some ABA tests I need to get my MPGuino recalibrated since I just replaced the faulty fuel pressure regulator which was sucking into the intake. I modified a new one to make it adjustable so I could lower the pressure a little since it was running rich in open loop.

yeah,it would be better if the dam wrapped around to completely shield the tires,but you should see an effect for sure

[COcyclist]

Grimm, it looks great with the chin splitter and almost factory. I think you will see an improvement in highway mpg.