Advice on aero mods for truck (2001 Dodge Ram 2500)

[Joenavy85]

that grill block is clean, very good looking

[slowmover]

There are a fair number of threads on dieseltruckresource, cumminsforum and turbodieselregister relating to FE. IMO, the ones worth reading have to do with how to drive versus how to mod (adding aftermarket gimmicks). I stay on top of the 3rd Gen trucks, but haven't read as much on 2nd Gen as you have (and looks very clean!!).

mopar1973man has a nice site, and this link to better FE with a CTD is a good start. His "Hard & Fast" rules are from the famous KENWORTH and CUMMINS White Papers on Fuel Economy.

Some of the available mpg instrumentation doesn't work well for 3rd Gen so I've not pursued it. But a rule of thumb that seems good is 6&6: 6-psi of boost (intake manifold pressure) and 600-F EGT (exhaust gas temp) and lower is where best economy will be found. (And a 2nd Gen thread to this topic, here.)

Were yours mine I'd focus first on record-keeping: average mpg and average mph as interrelated data to analyze FE. Metro traffic averages 15-mph, and big trucks 50-mph. If your truck is at 22 mph then rolling resistance changes will mean more than aero. If you are above 30-mph then the aero will really start to pay. Not saying don't do it. But take the low-hanging fruit first: LRR tires, MOPAR winter front, year-round use of block heater, no idling, max speed of 58-60 mph, etc.

For aero -- and those boxes -- I'd look to big truck tarp or RV skirting manufacturers for a HD vinyl snap-on bed cover to fit your truck. Add the Dodge Towing Mirrors for yours (no penalty, IMO; or the CIPA towing replacements) to help with backing. Or, a camera on the tailgate. KamperBob has a slick set-up shown in a post here about his rearview camera he "accesses" from the rearview mirror. Ultimately I would rather have a form-fitting fiberglass bed topper with side and rear openings over the boxes extant. I would talk with LEER or ARE about a ladder rack that mounts "flush" in some fashion for when you need it. (Maybe a metal plate across roof plus detachable tie downs?)

Your potential numbers are easily as high as mine. There are 3rd Gen guys with 4WD and auto trans meeting/beating mine. It's all about the calendar year average; or, cents-per-mile.

Here's a link to a thread where I went on with another big truck driver (that itself includes links) on BSFC versus speed in regards shifting the man trans CTD. Think operating range. Here's a table to correlate your auto trans.

The graphs for 2nd Gen (early) I posted recently on the thread here about BSFC numbers (Post 'em!).

.

[wjbell]

Originally Posted by slowmover

There are a fair number of threads on dieseltruckresource, cumminsforum and turbodieselregister relating to FE. IMO, the ones worth reading have to do with how to drive versus how to mod (adding aftermarket gimmicks). I stay on top of the 3rd Gen trucks, but haven't read as much on 2nd Gen as you have (and looks very clean!!).

mopar1973man has a nice site, and this link to better FE with a CTD is a good start.

Some of the available mpg instrumentation doesn't work well for 3rd Gen so I've not pursued it. But a rule of thumb that seems good is 6&6: 6-psi of boost (intake manifold pressure) and 600-F EGT (exhaust gas temp) and lower is where best economy will be found.

Were yours mine I'd focus first on record-keeping: average mpg and average mph as interrelated data to analyze FE. Metro traffic averages 15-mph, and big trucks 50-mph. If your truck is at 22 mph then rolling resistance changes will mean more than aero. If you are above 30-mph then the aero will really start to pay. Not saying don't do it. But take the low-hanging fruit first: LRR tires, MOPAR winter front, year-round use of block heater, no idling, max speed of 58-60 mph, etc.

For aero -- and those boxes -- I'd look to big truck tarp or RV skirting manufacturers for a HD vinyl snap-on bed cover to fit your truck. Add the Dodge Towing Mirrors for yours (no penalty, IMO; or the CIPA towing replacements) to help with backing. Or, a camera on the tailgate. KamperBob has a slick set-up shown in a post here about his rearview camera he "accesses" from the rearview mirror. Ultimately I would rather have a form-fitting fiberglass bed topper with side and rear openings over the boxes extant. I would talk with LEER or ARE about a ladder rack that mounts "flush" in some fashion for when you need it. (Maybe a metal plate across roof plus detachable tie downs?)

Your potential numbers are easily as high as mine. There are 3rd Gen guys with 4WD and auto trans meeting/beating mine. It's all about the calendar year average; or, cents-per-mile.

Here's a link to a thread where I went on with another big truck driver (that itself includes links) on BSFC versus speed in regards shifting the man trans CTD. Think operating range. The graphs for 2nd Gen (early) I posted recently on the thread here about BSFC numbers (Post 'em!).

.

I've been a member on those forum since I bought my truck in 07, lot's of good info. And lost of good ideas I'm getting here.

Here are some grill blocks I made about 3 years ago and have been running them year round. Even in Sacramento, Ca summers of 100+ I don't have any cooling issues. The top two grill openings are covered in clear plastic about 1/4 thick. The bottom ones are abs with holes drilled to allow some air in.

[slowmover]

Sorry to repeat what was known to you, ha! The grill blocks are great looking. I, too, have been looking at upper grill opening blocks but am more concerned about the lower openings. Looks like you nailed the solution! I'm going to copy what you have. Now, what else are you hiding . . .

I keep daydreaming that I can afford to have ALUMI-LINE, CLASSY CHASSIS or someone build me an aluminum aero topper (unless Bondo takes off with his) that is contractor-type as to being truly secure. I don't miss having no interior rearview most of the time, and wouldn't want it on a "secure" topper. I like the original Aerolid for the ability to move the center section up and down per load type.

Maybe an extended front air dam like ol' crabbelle or on this site, like Big Dave. I like the side skirts as well. Even though I have to take a deep breath, first, about it being a Powerstroke, his experience as shared is the truck diesel inspiration, IMO.

.

[wjbell]

I decided to pull the rack off because I think I can make a raised bar that goes across the boxes up front. Something that sits right at cab height. So I've been working all weekend on it. Sold the rack and mounted boxes only. I had to make legs for the boxed that mount to the bed for support, made them out of 1" angle iron. Nice and solid. Removed about 200-300 pounds of weight and got rid of a huge source of drag. Now I can start working on mods like something covering the opening from the cab to the boxes and maybe even the top down to the boxes.

As soon as I get an idea of mileage gains I'll update the thread.

[slowmover]

Big change. A CTD is fairly oblivious about weight (to a point) but it's all to the good aero wise. Looking forward to what you come up with.

[wjbell]

Originally Posted by slowmover

Big change. A CTD is fairly oblivious about weight (to a point) but it's all to the good aero wise. Looking forward to what you come up with.

Yeah, I kind of thought the same thing. 300 pounds to a cummins is not much, but the aero should be significant.

The other day I went to a store a few miles from me and was practicing the pulse and coast technique. Getting to this store there is some stop and go but there's a couple good stretches where it's about 50mph. (some good coast time) I did it the other day (with the rack) and the scangauge read 16.5 average mpg. I went to the same store today (without the rack) with the same coasting technique and when I got home the scangauge read average 18.0mpg.

Now granted, I might have been a little more careful with the go pedal today because of anticipated gains, but not much. It seems like there's an improvement, I'll have to get it on the hwy to really test it out.

[slowmover]

Auto trans, right?

[wjbell]

Originally Posted by slowmover

Auto trans, right?

Yeah. And when I do the coast I put it in neutral, it seems like there's a little drag on the powertrain when you leave it in drive and coast. Which brings me to another question... I put it in neutral the other day on the hwy and when I dropped it back into drive it was like it came back into gear in third (regular drive), wound up for a second and then shifted into overdrive. So I thought that might not be that great to do. It's like the computer has to re initiate the trans into top gear before it decides to put it in overdrive. Works fine when you're not up to speed for overdrive, I'll probably keep my neutral coasts to below 60.

[BamZipPow]

Looks good!

You might want to consider putting some footers on those legs to disperse the force/weight across the footer instead of the leg. If not, you could end up punching through the liner and bed over time.

In making a transition cover from the cab to the side boxes, what sort of materials are you considering? If yer thinking about using metal, you might want to consider roofing flashing.