Doin what they say cant be done.

[Fat Charlie]

My weapon of choice:



These things are awesome.

[ECONORAM]

I believe you can do it! In fact, I have wanted to buy a RAM SRT10 and do the same thing; get 20mpg highway with it.

Aerodynamics will go a long way. I didn't start seeing what I considered "good" mpg numbers until I covered nearly the entire belly. Including the gaps between the frame rails and the body, from tire to tire. My truck has almost everything covered to the rear axle, and I even have panels covering from the rear tires to the rear bumper, save the spare tire area.

Also, I swapped my clutch fan for an E-fan, and so I noticed I needed a type of vent between the belly panels. So, I have a 1 inch spacer where the panels meet, with the leading panel sticking lower and slightly overlapping the trailing panel...in a type of cowl flap effect. Did this for the panels running between the frame rails. I am using 0.040 or 0.050 inch Aluminum 3032, I think.

My engine bay belly panel is ABS, with cutouts for the wheel wells. I do cover the lower control arms also, with part of that panel. The flexing is slowly wearing on it though, I can see cracks developing. But that has taken a couple years.

I use corroplast for side skirts. Maybe I should post some pix in my garage. Double up corroplast if you use it like this; single thickness flops around way too much.

I have quarter circle shaped front fairings forward of the front tires. They look a little like I cut a missile silhouette in half lengthwise. They work great on the highway, but I've torn them up on parking blocks and steep driveways. ABS isn't the best material for that. Corroplast worked better, but looks a bit hideous. [edit] the next version may be corroplast covered with some thin bailer belt.

I tried a grill block, but it was costing me a little mpg (5%). Didn't seem to help my warmup cycle that much, maybe because I use a block heater in winter.

Sorry about the book, but I've been working on this a long time.

[ECONORAM]

Originally Posted by Sparkeysmall

polycarbonate. and i bought a jigsaw and ended up using scissors and a razor blade...

and 1" self tapping screws. i know over 170 of 'em. i used one box and a few out of the other i got.

---

in short. it looks absolutely dreadful.

still has a few rough edges to get off, and my "no tape measure" method had a few issues. but. its sturdy and so far hasn't fallen off. i need to get another panel to seal off the back and level it off. i put some curve into the rear cross to help with the load.
anyway. so far i can definitely tell a difference. it coasts much farther then before. and my instant gauge reads a few miles higher than usual. so hopefully this tank will go awhile further.

I don't think it looks all that bad.
My ABS cutting method may help with the polycarbonate. I use a straight edge and run a box cutter knife where I want the cut. I run the box cutter over and over the line until I get a nice groove cut into the material. With ABS, I can then bend the sheet and it breaks along the line I cut. Most of the time. If I cheat and don't cut it deep enough, then it can fracture off the line.

[oil pan 4]

Is the SRT10 the 8L or the 8.4L V10?

[ToddT58]

Great thread. I'm like you in that I drive a larger truck for work but still strive for better economy.

A guy on a Powerstroke forum got up to 23mpgs when most folks were happy if they got even close to 20. How? Biggest impact was going to an add-on Gearvendors overdrive unit on top of a rear diff ratio change. The goal: lower rpm.

I find 2,000rpm is the sweet spot for efficiency. Climb above and kiss the economy good bye. I now have a 6.6 LMM Duramax and it cruises at low rpm. That brings up another question: cruise at max torque or minimum rpms?

[ToddT58]

By the way, I used to have an SA200. The guy who owns it now chopped the shroud. May help on aero.

When I drove a gas vehicle, I drove by a vacuum gauge. The higher the better. Back in the late '70s gas crunch, I put my Ford van on a diet. My goal: 2mpg with a 36 month payback due to efficiency. Intake, headers, moderate 4bbl plus a vacuum gauge met my goal! Then again, that was from 12mpg to 14mpg!

I want to work on a belly pan. Considering fabric that can be removed such as Dacron like we use covering fabric airplanes.

[gumby79]

Originally Posted by ToddT58

...I want to work on a belly pan. Considering fabric that can be removed such as Dacron like we use covering fabric airplanes.

Look at Oratex it's the up and coming replacement for Dacron, ~ 17 years into the FAA certification testing. Oratex Aircraft Fabric very easy to repair . And no Doping,

[ToddT58]

Yeah, I remember the days of doping Grade A cotton and Stits PolyFiber! I wonder if we could make something like the toneau covers from the '70s with snaps?

[Sparkeysmall]

Originally Posted by freebeard

That's probably what I meant. I'm trying to cut some clear corrugated right now. I want to use this:



Hot nichrome wire. I got the 2 D-cells, but I apparently need to scavenge a coil spring out of another flashlight. It should work pretty well. I really dislike PVC, and prefer redwood benderboard. It's a landscaping material. This was done [temporarily] to research the shape:




If it was glued up in laminations it could make a very stout structure. Cross-cuts are easier than PVC pipe.

Try 3/16th inch pop rivets instead of the sheet metal screws. No more trouble and a smoother finish.

My only thought on using a hot wire to cut the pilycarbonate with is that it would have to be large enough to fit the panel within the hoop that transfers the current from one side to the other. You would almost have to make a table top version as it would be so bulky to be hand held. Another thought is that the hot wire would cut with far less sharp edges. I got one spot on my finger holding up the side panels on my topper.

Btw. I always wanted to make a beetle even more aerodynamic. Although looking at one they should be "perfect" with the sloped back and round front. But it just isnt sloped enough.

An old beetle is on my "got to have one" bucket list of cars. My favorite that i cry about daily for getting rid of was my '95 mazda mx-5. 40mpg through the mountain pass. So much fun.

---

So. After about 80 miles. My city average has climbed .7 mpg from usuall at 11 mpg. So im assuming the topper and oil pan heater are doing something good. Ill be hitting the highway to see family saturday. And the best ive gotten on the highway was 12 avg. im hopeing to be able to drop the suspension while im over there. The topper looks like a joke with the truck still sitting so high.

Anyway. I finished the topper today. Looks a ton better. But still aint perfect. From the side it looks good but all other angles its an eyesore. And i have to have a side mirror out as i just cant see if anybody is in the lane to the left or me without it. I can still see right side though. I had some thoughts about making clear plexiglass boattails for the mirrors. So you can still see behind but with less drag. Only problem i can forsee is the plexiglass making things difficult to see. Perhaps i should look at some smaller mirrors to put on the side.

Im at work now so ill get some pics up soon. (Done) (ok. Ill have to flip that picture when i get home.)

[freebeard]

My only thought on using a hot wire to cut the pilycarbonate with is that it would have to be large enough to fit the panel within the hoop that transfers the current from one side to the other. You would almost have to make a table top version as it would be so bulky to be hand held.
....
Btw. I always wanted to make a beetle even more aerodynamic. Although looking at one they should be "perfect" with the sloped back and round front. But it just isnt sloped enough.

My parents actually made on of those; it had maybe a 10" throat. It was powered by a Lionel train transformer, which I still have. I took a picture of it about the same time.



The contradiction in the Beetle body is it uses the rooftop vortexes to point air down into the intake below the back window. So improving the streamlining degrades the engine cooling. Body taper starts at the B-pillar, which is good; but the rear fenders lose back any gains.

Here's the thread from 2014 about the boat tail: http://ecomodder.com/forum/showthrea...tle-28272.html