Report: Improving the Aero Characteristics of a Dodge Ram Pickup Truck

[ECONORAM]

Originally Posted by MetroMPG

That air dam - is it an OEM piece?

(EDIT: removed my earlier comments about the air dam. Need coffee.)

Highly recommend you get the ScanGauge. It'll pay for itself in fuel savings, and you'll use it more regularly than a laptop based gauge.

No, the splitter is not an OEM piece, but I did model it after the Rumble Bee lip spoiler. That spoiler is thicker, but gives the same basic appearance. Here is a picture of a Dodge RAM Rumble Bee. (it is still a prototype. ) RumbleBee.org - The Dodge Ram Rumble Bee Owner Community :: Album
The lip spoiler I refer to is the black piece at the bottom front of the spoiler. I doubt it extends back more than a couple inches. Mine is 16 inches from the center straight back.

[MechEngVT]

Econoram:

Have you thought about adding fuel log info on your truck? I'm curious about how well you're doing with your mods as I've considered doing some very similar things to my truck but haven't made the time. If it looks like there's enough benefit it might incentivize me to make time.

I don't know if Dodge fixed or changed the A-pillar design on later model years but I've always noticed that at high speeds (70+ or even 65 near trucks or with crosswinds) air separates the door from the bulb seal at the top of the windshield because air shedding sideways off the windshield will get underneath the door and push outwards combining with the outward force of the pressure low along the front side windows. A lip seal similar to what you used as a bed fairing might help prevent this as long as it doesn't rub and cut on the bulb seal when opening the doors.

BTW the "Rumble Bee" air dam is part of a Mopar aftermarket body kit that was available since the 02's first went on sale. I think the air dam only fits on Sport package trucks though. I'd be willing to test fit one on my truck and test it out, but last I checked they were pretty expensive.

I noticed on your vehicle profile you're running an electric fan...would you mind telling me which model and where you got it? Have you noticed any gains from it?

[ECONORAM]

Hi MechEngVT,
I am running a Zirgo 2700 cfm unit. I had a weaker 2100 cfm unit from Flex-a-lite (did not know it was not strong enough until after I installed it), but when it would not cool the truck down enough, I stepped up to the Zirgo. I got both off of Ebay. I could have simply bought a full up Flex-a-lite 180 kit from AIRRAM or Moe's Performance, but I figured I could do it all myself. I did, but still bought a fuse holder, thermo switch, relay, and some mounting hardware.
Yes, I was toying with getting a Rumble Bee lip spoiler, but I do not have a sport bumper, and don't want to spend the extra money on one because it still will not have proper flare around the front wheels for good aerodynamics.
I am looking next at sealing the gaps around the windshield, and the door to body gaps. Figure that should help a bit too.
I do keep a logbook, but it is all hand written. Guess I could type it into the site, so you all can see what I've been up to. I hope to take a nice long trip down to St. George or Las Vegas at Christmas to get the truck on the road for a while and see what it will do. I have measured 23-24 with my in-cab mpg meter, and tracked the changes in the mpg with the distance covered, but a long trip would be better.

[max_frontal_area]

Originally Posted by ECONORAM

I am running a Zirgo 2700 cfm unit.

were you able to increase your FE since ditching your mechanical radiator fan? are your coolant temps slightly higher as a result? are you running a
205 deg thermostat?

[ECONORAM]

Hi max_frontal_area, I did not do before and after tests, so I cannot say if there's a significant FE gain or not with the fans. There was no weight change; the clutch fan and the electric fan with relays weighs the same...
I did swap more for the noise reduction, as the engine startup fan noise really bothered me. I do have the stock 193* thermostat. I also learned that the air in Utah is thinner, such that is actually makes a noticeable FE improvement. I've restarted monitoring the truck, as I've only hit a max average of 20.5 mpg here in OK.

[jungle]

EconoRAm; what did you use to help fill the gap between the cab & box? would it be better to have it attach to the cab vs. the box?

one thing I dislike about my 3rd gen Ram and holds true for your 4th gen, is that the bumper and front lip get narrow at the bottom exposing more of the tire. I am trying to come up with a way to address that without it looking tacky.

[ECONORAM]

Hi Jungle, mine is actually a 3rd gen also. I agree, the exposure to the airstream the front tires get isn't a good thing. My ultimate preference would be a RAM SRT10 bumper cover. But when I started this process, they were $1K a piece. So, I've tried a couple things along the way. Most to my wife's chagrin, but effective. Here's the latest flavor:
I have used foam weatherstripping between the cab and bed. Ideally, I'd weld it together but that would be difficult to do properly... I am looking to get some rubber weatherstripping for the gap, or maybe cover both sides with some saran wrap and spray in some expanding foam.