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Discussion Starter · #1 ·
Well, here I go again... starting with the simplest mods today.

first up was the half grill block...



Cant see it huh... nice... top half of the grill is blocked from behind. Warm days today & tomorrow for testing (highs tomorrow in upper 80s)

Next I will work on V2 of the lower air dam, bed seals and rear tire spats.


mpg data after aero updates
5/18/18 typical work week traffic, IATs up in the mid 70-95 range...
576.4 miles 25.974 gal 22.191 mpg, speeds 95% good, couple of higher speed drives on commute home.

5/19/2018
Side note, 2600 mile average over 5 tanks = 21.8 mpg.. <- whoop whoop...!



https://www.cumminsforum.com/forum/...376698-11-years-345k-clock-time-makeover.html

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2004 2500 555/5600 RWD QC/LB
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Need to cover EXTERIOR of grill. Idea is to direct air over hood.

In hottest temps you’ll have to remove it. Same for towing.

Been doing this ten years. Does it make a real difference? If you’ve sealed heat exchangers to each other to direct all flow thru rather than around them you’ll notice a difference

in the time to complete warmup (which is oil, not coolant).

When coolant temps start to run above factory setting, remove the upper grille block.
 

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Discussion Starter · #3 ·
Need to cover EXTERIOR of grill. Idea is to direct air over hood.

In hottest temps you’ll have to remove it. Same for towing.

Been doing this ten years. Does it make a real difference? If you’ve sealed heat exchangers to each other to direct all flow thru rather than around them you’ll notice a difference

in the time to complete warmup (which is oil, not coolant).

When coolant temps start to run above factory setting, remove the upper grille block.

So Rams got it wrong? This video is what inspired me to re-install the block. It was not on the radar before seeing this.




Installed wheel well vents, front grill block and rear tire spats/air dams. pic later.
 

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Discussion Starter · #6 ·
long road trip on tap for today, hiking in the Gorge area (2~3 hrs drive to first TH) will be a good satellite view test as the plan is to fill back up at the end of the day.
 
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Interesting idea on the wheel well vents. Was thinking about that the other day while watching graveyard cars and they showed an old mopar winged car with vents on top of the fender and it made me think about the pressure in the wheel well.
 

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Yeah i am not to sure if those vents will do anything, will have to see what kinda spray comes out up there on the next rain.

Biggest think i see after a 180 mi drive is truck is more stable in dirty air and slightly better in clean air. Maybe this is coming from the grill block and a change in airflow over the hood?...
 
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Yeah i am not to sure if those vents will do anything, will have to see what kinda spray comes out up there on the next rain.

Biggest think i see after a 180 mi drive is truck is more stable in dirty air and slightly better in clean air. Maybe this is coming from the grill block and a change in airflow over the hood?...
I’m surprised you’re feeling something. It’s most likely from the grille block. I had a grille block on the little 2wd truck a couple years ago and it did help mileage but ran on the hot side so I took it off and the overhead trip meter started counting down after removing it so I’m convinced it helped mpg.
 

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Discussion Starter · #11 ·
Well thats the thing, i dont feel anything, its solid passing trucks and getting into thier wake. Used to be able to feel it when passing. Having the top grill blocked allowed intake temps climb and stay up around 103-107 on the way back. Still need to fill it up.
 
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Discussion Starter · #12 ·
Filled up and recorded a 21.8 mpg (data in 11yr thread). With iats as high as they were in the return trip, its possible iat comp timing is off some and could be tweeked, it did get a tad bit smokey while that hot. Having gone from 89-109* the sotp meter says between 85-95 is the sweet spot with the current tune. Also should be noted that i did get to he part of the sunday afternoon I5 parking lot that occurs all too often, for 10-12 miles or so.

Commute in, prob a placebo effect or it could be the warmer air temps but it seems to me that coasting on the flatter hills is more feasible now. "Heat wave" almost over and a good portion of this tank will be under similar conditions as the other tanks listed on the data post (11yr thread).

Oil gets changed this week, stiction additive goes in.
 
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Pretty good for the goofy driveability and the parking lot traffic. I wonder what the rear wheel spats are worth aerodynamically. I want to try those too.
 

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Discussion Starter · #15 ·
2 days now with updates in place, i am finding i am able to coast farther with clutch disengaged in familiar areas and with the upper grille blocked IATs are easier to get into the upper 70's in the cooler morning temps. I wont be surprised if this tank is a new high beating the current high of 22.299 mpg on the commute to work. (All time high was a 23.00* mpg driving down I5 to sacramento)
 

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Yeah not bad I think... what do you mean goofy driveability?
I was referring to the Smokey condition you mentioned with the higher IAT. probably wasn’t optimal for mpg.
 

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I’m gonna try the partial grille block next, any reason why you blocked the upper half vs. the lower half?
 
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Discussion Starter · #18 ·
Yeah timing is off now with higher temps..., Probably cause the fuel cooler is blocked since its in the upper grill area of airflow.

I did the top half to push air up over the hood, it also allowed engine compartment temps to rise better
 

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steve05, do you have a thread that details your fuel cooler install...I have been toying with this idea and would like to read more about it. Its on the fuel return line, right??

Thanks.
 

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