Quote:
Originally Posted by redpoint5
I wouldn't take it personally, that's Slow's way of conveying what he's learned. He's critical of my posts too, but often has very good points.
A 7% gain in fuel efficiency simply cannot be accounted for by a lower weight driveshaft alone. There are unaccounted variables at play.
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The datapoint is fine and appreciated, but clearly not sufficient.
I too wouldn't want to change out parts a bunch to do more thorough testing. Just enjoy the mod.
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I dont... at least I think I dont... I just dont have it in me these days to debate, discuss or argue (wouldnt really argue) any point. I've documented what I've done, recorded 90% of the fillups (all down below), the 10% are road trips where eco driving went out the window or tuning tanks where changes to the ECM tune occured.
22.7/21.8 = 1.0412... not sure where the 7% number came from ...
My goal here was just to share what I've done and what results at the pump I observed. A true test would need to be done on a dyno in a controlled environment. I recall there being a wind tunnel with a dyno setup somehow to simulate driving conditions, that would be ideal.
Two other comments... my truck has proven to me to be pretty consistent at the pump when the normal routes are taken. and anyone who can drive to the point where they can get a specific (minimal +/- mpg) is a way better driver than I. I can only get the max my truck has to offer via coasting on the hills, neutral when traffic is slowing and capping top speeds at 63~65 mph.
https://www.cumminsforum.com/forum/3...-makeover.html
https://www.cumminsforum.com/forum/3...iveshafts.html
495.5 miles, 25.087 gallons,
19.751 mpg Fan clutch, air dam in place, ~85 mi no fan.
52x miles, 70+ at times,
20.348 mpg, No fan power, rush hour traffic often and timing rattle. IATs mostly in the 60's and barely into the 70's for most of the tank, last 120 miles had IATs in the upper 70's low 80's with ambient temps being higher all day
518.3 miles, 26.338 gallons,
19.678 mpg No fan power, IATs mostly in the 60 & 70's, high winds & heavy rains for several trips on this tank.
497.5 miles, 25.586 gallons,
19.444 mpg no reason for poor mpg... road conditions were OK, one trip had heavy rain for a short distance. tweeked timing, IATs upper 60's to upper 70's.
404.8 miles, 20.717 gallons,
19.539 mpg, no reason for poor mpg, road conditions were OK, stuck in accident traffic for 45 minutes. Updated tune installed after this fillup. restored CT/IAT table to equal KGT file
29x.x miles, <unknown gallons>,
20.586 mpg, good weather, 70+ mph at times, 1000-2300 rpms used. fixed the tune, reverted the CT/IAT warmup table, took it back to the last KGT file table and left the IAT compensation table as it was. I can hear certain areas of the tune needing to have timing backed off a bit, most likely cause of the advance on the IAT table. Will fix this later as its a minor issue.
42x miles, <unknown gallons>,
19.527 mpg, great weather, Canada track trip, intermittent mis-fire/vibration started after 200 miles, cause unknown. MPG was looking great before that. First inspection points to a bad output TC bearing. does not seem like it would be related to a mis-fire, it could just be bad vibration being interpreted as a mis-fire. Will get the bearing fixed and go from there.
@350 miles on this tank, had to go back to a base file. Existing file did not want to run with ambient temps @30~32*. Found this out the hard way after coming back from Cali (flight) and no time to fix it. Base file is the one created by HPT when I vin locked my truck.
19.140 mpg 487.9 mi, 25.491 gal HPT base file installed, odo approx 0.5 mph off on low side
Current tank notes on 2/23... 33 mi in 4wd, ambient temps in the upper 20's, IATs in the 40-60 range, wheel install done. 70~75 mph @ times, minimal stop & go... @80 miles. Installed V2_0 air dam, then ran test runs to check it out, multiple runs testing air dams and IAT data collection. All still on base tune, new wheels installed.
551.1 miles, 27.847 gallons,
19.790 mpg
492.2 miles, 24.346 gallons,
20.202 mpg... speeds kept in check, hit 67 a few times but most of the tank was as expected. Winds and heavy rain on 1 45 mi trip but for only about half of that distance. Updated ECM with speedo & gear correction.
3/11/2018
Miles = 572.7, gallons = 27.232,
mpg = 21.030. TQ LOM = 22.7mpg speedo corrected, IATs climbing higher with a few trips into the 70's & 80's 21.3 mpg tune going in today 3/11
552.5 miles, 25.757 gal,
21.4 mpg. TQLOM = 22.2 mpg. ~23+ drive events from 3/11 thru 3/17, ~10-11 cold starts, couple of days with IATs up in the 80's, 1 into the 90's, mostly 60-70 range. A new personal best in the colder months, especially over a 6 day period. Speeds mostly 60-65, 67~70 a few times.
569.2 miles, 26.623 gal,
21.380 mpg. TOLOM = 21.2
Fan power connected 3/24
3/26
525.5 miles, 25.451 gal,
20.647 mpg TQLOM = 21.2
Lift removed, guilty of 70+ on several occasions...
581.0 miles, 26.913 gal,
21.588 mpg TQLOM = 21.3
4/5/2018
533.1 miles, 24.003 gal,
22.207 mpg. Lift gone, speeds 68 or less, fan disabled, coasting where it makes sense, IATs in the mid 60's, lower 70's. 04/05/18, 20 trips on this tank over 3 day period
<unknown miles>,<unknown gal>,
20.6x mpg (SIL drove & drove it hard...)
570.7 miles, 26.334 gal,
21.671 mpg, TQLOM = 21.3 mpg, nasty weather on the front and back end of this trip, Col River trip, 2 summits. HSS installed on this fill up.
4/20/2018
493.7 miles, 22.449 gal,
21.992 mpg. TQLOM = 21.6 mpg. HSS tank, warmer weather
04/21/2018 - truck retuned
4/23/2018
491.3 miles, 22.980 gal,
21.379 mpg. Truck retuned, not so kind to throttle at times during the tuning. IATs up into the 70-90 range, adjusted the pedal map.
4/27/2018 - way more 70+ mph speeds than recent tanks, stuck on the wrong side of the morning accident today and crept along for 20~25 minutes. Intake temps up there in the 80-95*f range. Both fans hooked up on low and are doing a good job of keeping temps in check. High connection not yet made, fan switch in hand & needs install.
4/29/2018
547.1 miles, 25.321 gal,
21.606 mpg.
5/4/2018
457.4 miles, 20.512 gal,
22.299 mpg
5/8/18
573.6 miles, 26.875 gal,
21.343 mpg, lots of 70+ mph, high iats, trailhead climb (wta day), passing on 2L rds.
5/12/18 Aero updates installed prior to fillup, front grill block, wheel well vents, rear spats
636.6 miles, 29.658 gal,
21.464 mpg, no attempt at for driving for mpg, lots of 70+mph, high IATs, steel toed boots on, and are not good for mpg driving! (foot injury)
5/13/18 Columbia Gorge trip, IATs on way back 105-108*f
349.5 miles, 16.012 gal,
21.827 mpg, speeds 68 or less. 359k miles
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.
05/22/18 Rain, heavy foot, 70+ IATs 70-95 range typical traffic
485.0 miles, 23.288 gal,
20.826 mpg,
05/25/18 bumper mod IATs good
275.4 miles, 12.643 gal,
21.782 mpg,
06/17/18, 464.9 mi, 24.395 gal,
19.057 mpg. Cali trip, 80+ mph
06/16/18, 435.7 mi, 24.093 gal,
18.084 mpg. Cali trip, 75+ mph
Retuned in higher rpms, set higher altitude maps = to sea level and reduced FP 2 mpa on ea table vs the lower alt table.
06/23/18, 536.6 mi, 25.535 gal,
21.014 mpg. Normal commute minimal eco driving, 70+ mph at times
******************************************
513.8 miles, 23.539 gal,
21.827 mpg
100% eco driving, IATs up in the 90's, IAT comp table corrected but timing not dialed back in.
DGAS tank... 7/22/2018
519.1 miles, 26.065 gal,
19.915 mpg... 75-85 mph, zero consideration for eco driving, Portlland race trip, stop & go rush hour traffic. A new personal best for this kind of driving...
479.3 miles, 21.095 gal,
22.721 mpg Aluminum driveshaft swap results. Consistent tank, commute traffic, IATs up over 100 in the afternoons, needs a retune, smokey. Note: This tune was not smokey last week...
DGAS tank 7/30/2018
319.1 miles, 16.172 gal,
19.731 mpg... Tuning tank, lots of downloads, experiments and hard throttle time. Tweeked rail maps slightly, main timing, cut duration by 2% and started working on Post timing. Advanced Post 0.25* in an effort to get the turbo spooled better, reduced the MM3 for Post and expanded its coverage up into the 2000-2200 rpm cells. Worked really well, ultimately I reduced fueling, advanced timing and gained more power out of it by reducing the delay from the Main event to Post event.
472.8 miles, 21.056 gal,
22.454 mpg... Tank was doing really well, discovered an air leak at airbox while investigating airbox mod...argh! Not sure if it was doing well because of the leak, or how long the leak was present.