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MPG improvements through aero mods

66292 Views 647 Replies 28 Participants Last post by  steve05ram360
Recently I'd seen a Chevy with with wheel splats (or mini air dam) in front of the rear wheels. I'd seen this long ago on the Audi TT I had and often wondered if there was any benefit to doing something like that to the ram. Well it appears Chevy felt it did contribute somehow to mpg improvement. Took a look at my trucks rear wheel openings to see if it was feasible to add one back there that dose not look obnoxious. Seems like it may be worth trying.

Another mod I'd thought of doing was adding a strip of plastic to close off the gap between the frame and the outer body panel, between the wheels. That would be out of sight, not sure if there would be any benefit or not in that area. Recently I read a writeup on the Ecodiesel that had a higher FE version of it, 2wd and it had side steps... side steps... really? They apparently felt it had an improvement.

Further reading (and getting back to) wheel well aero drag had me realize I have the rear fender liners. Not sure if that reduces drag back there or not when compared to the 1/4 liner that the truck came with. One of the thoughts I had once upon a time was to experiment with an louver on the fender liner in an effort to relieve some of the turbulence that occurs in the wheel wells.

At some point in 2018 I am going to revisit/install the 2nd air dam I had under there once upon a time. I plan to add the rear wheel front splat. That 2nd air dam was not even noticeable unless you knelt down and looked for it. AFter lowering the truck down I would expect it to have more of an affect on airflow under the truck. When I went from 3" spring to 2" spring that air dam started rattling, it was not prior to the spring swap. That told me airflow was actually hitting it. Any benefit from it I never did test for.

New Rams... I noticed a while back that that they had a seal setup somehow between the cab and the bed. I've looked at some of the truck liner seals to see if something could be had that would be cheap to pop in there but have yet to find one that would work ok.

I am thinking it will be hard to detect any change on any mod that is done as it will be a small change by itself. Collectively however it may be easier to detect. How? I'm thinking it will be easy to use the Torque app I use daily and record before and after data, looking at the calculated load on a longer loop that can be easily repeated. Where I"m at up in WA I can jump on the hiway and do an out & back easily to collect data for a 40 minute run... using CC of course and starting and stopping the log at the same points on the hiway.


Anyways, any thoughts or ideas out there worth discussing?

Disclaimer.... motivator, an evil one I will admit is to try and come close if not match the wifes new Mazda CX5's mpg of 24 mpg. Probably not gonna happen but time will tell. Remember, lighter wheels going on, going back to stock height and e-fans going in are in the near future and my truck was consistently getting low-mid 20's for mpg before the fan clutch gave me the finger. Its said that leveling kills approx 1 mpg, the fan is good for 1~1.25 mpg, lighter wheels???? unknown. If I get those 2 mpg from those 2 mods that should put me up into the 22-22.5 mpg range tank to tank (city & hiway combined).

Edit: Adding article link with useful info...
http://media.gmc.com/media/us/en/gm...news/us/en/2013/May/0516-gmc-pickup-aero.html

http://www.pro-touring.com/threads/101460-Designing-Aerodynamics-for-Track-Performance?



Front air dam re-installed


V2_0 of the air dam



http://www.audew.com/AUDEW-Universa...rotector-Lip-Splitter-Body-Spoiler-p-130.html

Look @ pic, velocity of compressed airflow -> rear exit of truck.
http://www.buildyourownracecar.com/race-car-aerodynamics-basics-and-design/3/


http://www.autospeed.com/cms/article.html?&title=Modifying-UnderCar-Airflow-Part-1&A=113181

http://www.autospeed.com/cms/article.html?&title=Modifying-UnderCar-Airflow-Part-2&A=113182


https://www.curbellplastics.com/Sho...93-in-x-48-in-x-96-in)-Haircell-P1-Fire-Rated

Truck aero study
http://people.cst.cmich.edu/yelam1k/asee/proceedings/2011/DATA/7-155-1-DR.pdf


V2_0 Air Dam...

http://www.cumminsforum.com/forum/3.../2412082-diy-air-dam-v2_0-a.html#post28028746


http://ecomodder.com/forum/showthread.php/rear-diffuser-1831-3.html

http://ecomodder.com/forum/showthread.php/underbody-panel-testing-12747.html


Blowing the vortex part 1
http://www.autospeed.com/cms/article.html?&A=113216

Part 2
http://www.autospeed.com/cms/article.html?&A=113217

Part 3
http://www.autospeed.com/cms/article.html?&A=113218

Part 4
http://www.autospeed.com/cms/article.html?&A=113219


aero mods thread... this is where I document what I tried.
http://www.cumminsforum.com/forum/3rd-gen-non-powertrain/2449106-aero-mods.html#post28435634
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LOL...That IS hard to see. Is that a 2nd gen air dam??

IIRC, the 2nd gen air dam I saw was bolted directly to and below the oem 3rd gen air dam, also hung down about 6", and looked really good.
 

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Just a thought, but for $50 you may want to try the 2nd gen air dam instead...it sits at the front of the truck, underneath the 3rd gen air dam, and thus will actually add to the aerodynamics of the truck.

Link to air dam at LMC was in my first post here.
 

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DEFINITELY post a pic if you do decide to do it...I can't seem to find the original thread that showed this mod and the pic is likely gone anyway due to the Photobucket scam.
 

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Discussion Starter · #25 ·
Will do... probably wont though. Lowering my truck back down to stock height and the added front air dam area would be a problem for me... still go off road from time to time. Having the 2nd air dam set back a ways works out ok so far.
 

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Discussion Starter · #26 ·
doing a lot of reading on aero mods, looking at things that can aid the underside that wont stick down too far. Seems like a rear diffuser would help a lot to break the low pressure area behind the tailgate. Trouble is getting something that would work and still fit with the overall plan of being hardly noticeable.

Vortex generators keep coming to mind in an effort to break the low pressure in the rear. Another thought was looking into the wheel well turbulence and finding a way to reduce the drag in there. Not sure if that is really a problem or not with our trucks but one thing came to mind was to run a "drain hose" of sorts from the back of the truck near the low pressure area up to the front wheel wells. From what I've read, high pressure will move towards the low pressure... if I understand it correctly, relieving the pressure built up in the wheel well will reduce drag. Another long time thought was to use a naca duct positioned in a way to create flow in a hose and use that flow to draw air out of the wheel well areas.

Any input is welcome... just thinking outside the box hear while doing research...
 
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Just a thought, but for $50 you may want to try the 2nd gen air dam instead...it sits at the front of the truck, underneath the 3rd gen air dam, and thus will actually add to the aerodynamics of the truck.

Link to air dam at LMC was in my first post here.
Seafish, do you have a pic of your setup and how you mounted it? I’d be interested in seeing how you did it. Thanks.
 

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Discussion Starter · #28 ·
140ish miles on the Odo with the fuel gauge just coming off the full tic mark... this is ~15 miles higher than tanks I had in Dec. 2 things are different, 2nd air dam is in place and the front cover is half open... forgot to close it after the drive up from Cali. I suspect the cold air in the front is keeping the fan clutch unlocked.

The plan was to get the e-fans installed Saturday (rain expected) and push on with the trucks make over... however with what I see I may push that back a week and run this tank down before making the next change.

I had a thought on the way into work this AM, researching the light weight wheels I found forum threads where guys were shaving off time in the 1/4 times. Their stated wheel weight reduction was in the 8-15# range which makes me think if there is any mpg improvement it would be in the rush hour traffic, any up hill segments & any traffic light starts. Seems to me the higher the load the greater the benefit. Anyone with first hand experiences in this area? I came across a thread where a Subaru forester owner put on light weight wheels and low rolling resistance tires and gained something like 13% better mpg (~3mpg). His one complaint was the mush ride from the tires. My expectation is zero mpg change so anything will be a surprise.
 

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Seafish, do you have a pic of your setup and how you mounted it? I’d be interested in seeing how you did it. Thanks.
As I noted earlier, I have not yet done this and still cannot find the thread of the guy who did, That being said, it was a simple bolt on mod, with the caveat being that you had to drill the holes on the bottom lip of the oem 3rd gen air dam that lined up with the oem holes on the top of the 2nd gen air dam.
 

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Discussion Starter · #32 ·
Wonder why you have an issue, it worked for me...

Edit: I grabbed the pics in case it fails to work down the road.
 

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Another thing to bring up again is the 3rd gen 1500 bumper insert. In reading about aerodynamics & mpg improvements it is stated that sealing off the front as much as possible without sacrificing cooling is desired for better mpg. I still have my tow hook area insert installed. Had it in there the past 2 years with no cooling issues. Its a cheap easy mod that can be yanked easy.

You can see it in a pic in post #1

which shows me another area for possible improvement, right under the front grill there is a gap that can be filled. Also under the headlamps.
 

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I like that look. I’m thinking I’m gonna do this mod. Thanks for the info seafish and thanks to Steve for finding the pics and link.
 

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I like that look. I’m thinking I’m gonna do this mod. Thanks for the info seafish and thanks to Steve for finding the pics and link.
Awesome... I was just gonna ask if anyone would want to do it and report back results. If you start a thread on it can you link it here? Or your welcome to post results here if you like.
 
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Discussion Starter · #38 ·
Sheet metal trim pieces... does anyone know if Napa sells that stuff?

Looking to find a piece to block off the area between the bed & cab and then a different style piece to provide some blockage under the front grille. I looked at this today and it appears a piece can be attached to the upper bumper plastic just under the grille. Find the right style and then that area is sealed off. It would also be good to find a seal for under the headlamps.
 

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Sheet metal trim pieces... does anyone know if Napa sells that stuff?

Looking to find a piece to block off the area between the bed & cab and then a different style piece to provide some blockage under the front grille. I looked at this today and it appears a piece can be attached to the upper bumper plastic just under the grille. Find the right style and then that area is sealed off. It would also be good to find a seal for under the headlamps.
I would highly recommend using self adhesive CCF gaskets in different thicknesses for the different areas you want to close off, particularly the cab/bed space, as you would NOT want any sheet metal scratching paint as the bed and cab move differently from each other while driving. The CCF tended to be either black or dark grey and would also not be very noticeable in those spaces.
 

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I like that look. I’m thinking I’m gonna do this mod. Thanks for the info seafish and thanks to Steve for finding the pics and link.
I think it is pretty much a no brainer unless you do a lot of off-roading!!!


I'll get around to it one of these days (i.e. years...LOL!!!)
ALSO, I will use stainless bolts and ny-lock nuts to do it.
 
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