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Old 10-18-2016, 11:40 PM
Tiger Tiger is offline
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Default 6.7 Cummins undelete Mods

6.7 Cummins EGR disable/ reduce, eliminate active regen

There are a lot of people that don’t want to remove the crap named emissions equipment and risk fines etc. I did a lot of reading on the subject and did come up with some solutions to help with the 2007.5-2012 Rams. I cannot report on the def trucks but this may work on them as well. Will most likely work with any DPF truck including Duramax and Powerstrokes.

Reduce or eliminate active regen process: There are 2 types of Regen processes associated with DPF equipped trucks. Active Regen that all are very familiar with, when the trucks ECM commands more post injection fuel added to the exhaust stoke triggering a burn off of soot build up in the DPF filter. This normally happens every 50-100 miles in stock trucks and your mileage takes a dump. The second type of Regen, Passive regen usually goes unnoticed and occurs when towing or longer highway runs. The exhaust gases remain hot enough for a sustained amount of time that allows the soot in the DPF to burn off. Passive regen does not hurt your mpg.
After thinking this over, I decided to come up with a mod to promote passive regen, thus reducing/eliminating the negatives of active regen. To keep the exhaust gasses hot enough requires insulation to reduce heat loss. I purchased 50ft of exhaust header wrap with an aluminum coating on one side. 50ft was enough to wrap from the downstream side of the Cat to the DPF and wrap the DPF. The metal straps are not necessary, I preferred using bully wire about every 1 1/2'. Wrapping sections makes it easier to wrap and remove sections of pipe if desired. I didn’t remove any sections by the way and spent about 30-45 minutes wrapping. It was tricky wrapping the DPF filter due to the shape, take your time, you may want to wrap in an X shape to get the funnel shape parts of the DPF.
No need to worry about this mod affecting EGTs, since it has nothing to do with temperatures coming from the exhaust port.
So, how does it work? I have had my pipe wrapped for 2 weeks and approx 500 miles and see a big improvement. I have not had the instant mpg pegged to the left indicating active regen once!! Even city driving it has not gone into a full regen. It appeared to do an abbreviated one, my instant did some flickering to the left like the ECM may have added a minute amount of post injection. My mpg is up about 1 1/2 to 2 mpg from what I can see so far.

EGR mod: Another mod I have been working on is to reduce/eliminate EGR function. I was hesitant on this subject since many subscribers stated limp mode and dealer trips were the result. I knew the pre 2013 Rams have over active EGR and Ram greatly reduced the amount of EGR in the 2013 & up trucks. Seems like a better approach is to fool the EGR temperature sensor. The sensor reads resistance as exhaust temp. Seems like people have unplugged the EGR temp sensor and put a resistor in the circuit to send a low temperature signal to the ECM. When the ECM sees this, the EGR valve is kept closed. While this sounds like the Holy Grail, there are some minor short falls. I used a 1/4 watt, 10 ohm resistor. Bend the ends to form a U shape. Then bend a small amount of the 2 end wires back on itself making it double thick. Insert one end of the resistor into each socket of the EGR temp connector. This simulates the sensor and the ECM thinks its plugged in. From what I can tell the EGR is staying closed. I noticed a slightly louder engine idle to. Mabe someone can answer why that is? I think its due to fresh air vs crap air or did the map change to a colder climate one? It works pretty darn well with 1 issue, you will eventually trigger a CEL, P040 open EGR circuit. I have gone 1 to 2 days between codes and have not caused a limp condition or power loss. I simply clear the code since I don’t like driving with a CEL but I don’t see any negative performance issues with this method. Duramax owners have a Holy Grail called the finger stick. Anyone try making one for Cummins??
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  #2  
Old 10-19-2016, 07:13 AM
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MnTom MnTom is offline
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Thanks for the great write up! That sound almost to simple, but it appears to work. Just out of curiosity, how did you decide to use the wrap to keep temps up? Things like this make me glad to have my old 12 valve!!

By the way, WELCOME!! I hope you have fun and enjoy the forum!
Tom
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5° timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound

Last edited by MnTom; 10-19-2016 at 07:20 AM.
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Old 11-05-2016, 09:18 PM
Tiger Tiger is offline
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Other members post your ideas: This can become a resource of information for diesel owners that dont want to delete.

Another mod I have been using is a Volo FS2 chip. I have tried other chips out there, most recently a Mini Maxx. I was wondering if it would mess up my computer mpg like alot of other chips will, but was close to hand calc. I removed it when I found out that the mild w/ATT tune was associated to head gasket failures due to boost spikes using default settings with the stock and mild tunes. I experienced spikes at 1/2 throttle and backed out before boost got too high. I was at approx 35 psi in a stock truck. My DP could have been as high as 70 psi, not good for your HG. I did experience a little better hwy Mpg but about the same city. So, back to the Volo. When I first put it on, I did notice an increase in responsiveness especially at low speed roll on from approx 5 mph under light throttle. The responsiveness was noticeable at all speeds but was definitely noticed at lower speeds. Also, I did a test using a long down hill grade on the hwy to see how high i could get the instant to go up. Traveling at 65 mph, i would take my foot off the throttle and hit the reset: stock it would slowly get up to low 50s, when I did it with the Volo, 99 plus almost instantly. I see the instant jump to the right when ever I ease up on the throttle or take my foot off. Also I dont smell any diesel from the tail pipe with the Volo installed. Over all I have seen approx 2 mpg increase and better driving experience. If you dont want to rewrite your ECM but still improve your truck, the Volo might be worth giving a try.
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2012 RAM 2500 Laramie, Crew cab, 6.7 Cummins, 4x4, Bright Black, 35 Nitto Terra grappler, muffler delete,
Mini Maxx .38 mild

2006 RAM 2500 Big Horn,Quad cab, 5.9 Cummins, 4x4, Brilliant Black, Superchips, 35 Falken Wild Peak (gone)

Last edited by MnTom; 11-07-2016 at 03:07 PM. Reason: Fixed a typo
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Old 11-28-2016, 02:13 AM
Tiger Tiger is offline
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Default Updates Mini Maxx

Thought I would post an update on my truck tuning. As mentioned earlier, my 12 is basically stock except for the EGR fooler mod, muffler delete and rerouted the CCV crank case ventilation to vent to outside air, the oem runs back into the engine witch will gum up the intercooler and intake. In my quest for more efficiency I put the mini maxx back on. With lots of info gathered I decided to try some different tunes. Here are the results of what I have tried so far:
6.8.38 mild w/att : very strong off bottom with a pull that will put you back in your seat at 1/2 throttle !! I like this tune except for the fact that is over boosts the stock turbo. Stock turbo comes apart when high 30's boost levels are hit. Also, at the higher boost levels drive pressure goes from 1:1 to 1:1.5 and higher. High drive pressures are associated with excessive cylinder pressure and head gasket failures. I set my defuel at 32 psi and could hit that without trying! Good economy, I averaged 18 mpg.
6.8.47 mild w/att : Thought it would be the same as the .38, nope. Still overboosts like the .38 but is very doggy to drive. Felt almost stock. Not vey good mileage. I noticed EGTs were lower, which leads me to believe this was a CARB EPA compliant tune to lower NOX. I feel sick that they think this way.
6.8.47 modified with 6.8.11 engine tuning: A lot of users raved about the 6.8.11 tune back in the day and H&S made a version that worked with 2011 up trucks. Yes it rattles. Initial throttle response was good but flattened out right after that. Well, H&S was right about this one when they said to use newer tunes. LOL
6.8.38 mild no turbo : Wow, I think I like this one. Strong throttle response that keeps going as long as you keep you foot in it. It is softer in the middle that the turbo version but is not building excessive boost pressure like the turbo version does. I'm seeing mid to high 20's for boost. Dont have a lot of time on it but can already see this tune will give good economy.

I may give the hot damn a try later down the road to see how it compares in the economy area. I think the mild will be more efficient though. MCC tuning is on the horizon. Any other H&S owners please post your experiences with your tuner.
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2012 RAM 2500 Laramie, Crew cab, 6.7 Cummins, 4x4, Bright Black, 35 Nitto Terra grappler, muffler delete,
Mini Maxx .38 mild

2006 RAM 2500 Big Horn,Quad cab, 5.9 Cummins, 4x4, Brilliant Black, Superchips, 35 Falken Wild Peak (gone)
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Old 11-28-2016, 08:28 AM
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From what I understand, timing has quite a bit to do with the fuel economy. If you were able to over boost did you have any smoke? You would think with that amount of fuel the EGTs would be running fairly high too. Were they?
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5° timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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Old 11-28-2016, 12:23 PM
Tiger Tiger is offline
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Default Vgt

The VGT turbo that is stock on the 6.7 Cummins was never designed to see more than approx 35 psi of boost. I was getting that very quickly at 1/2 throttle and would back off. Its the drive pressure on these VGTs that you have to watch out for. At 35 psi I could be at 60 -70 psi drive pressure. The VGT starts out at a 1:1 ratio but jumps to as much as 2:1 DP to boost ratio. There is no wastegate to blow off the excess pressure, it stays in the cylinder which can/will blow your head gasket on the 6.7. Lots of threads on this subject.
Did you see a mpg increase with the 16° timing? Stock timing on gen 1's is around 12° I think.
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2012 RAM 2500 Laramie, Crew cab, 6.7 Cummins, 4x4, Bright Black, 35 Nitto Terra grappler, muffler delete,
Mini Maxx .38 mild

2006 RAM 2500 Big Horn,Quad cab, 5.9 Cummins, 4x4, Brilliant Black, Superchips, 35 Falken Wild Peak (gone)
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Old 11-28-2016, 08:06 PM
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I didn't realize there was no waste gate on the VGT. I guess that makes sense if you are going to use the turbo as an exhaust brake too. Sounds like the drive pressure can get out of hand real quickly if someone is not paying attention. On my 5.9 it is pretty easy to replace the head gasket (did two of them). What takes the longest is if you need to have anything done to the head.
It has been so long ago since I set the timing I can't remember if I actually gained anything far as mileage when I bumped it up. The timing slipped quite low on me so I needed to do something with it. I am questioning if it may be a bit higher than 16* due to if I am pulling a load and the RPMs drop to about 1500 the turbo will start barking. I have been told that is because of the timing I am running. For mileage, I have run about 8 tanks of fuel empty with the cruise set on 75 mph (2000+ RPM) and have seen a consistent 19.75 mpg hand calculated. If I am running 60 mph or less I have seen 23.4 hand calculated. Towing my fiver I see about 11.5 at 65 mph, so I am pretty happy with the mileage.
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5° timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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Old 11-29-2016, 07:47 PM
Tiger Tiger is offline
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Wow, 23 mpg with 3.73s ? Timing advance will yield better mpg. The stock 6.7 CTD lack timing advance. I think there is way too much CARB type tuning involved. Just did a highway run to see what kind of mileage I could get. I was averaging 20-21 mpg on a hilly hwy. on flat parts it looked like 22-23 mpg, but hard to say for sure since the flats dont last for long. I did suffer some regen to, which knocked me down to about 17mpg. I think I got a regen from running the Hot setting on the Mini maxx. When I was on stock setting, which is stock with added timing I believe, I didnt notice any regen going on. It was on the way home when I bumped it up to Hot setting. I really like what the tune has done for the truck. Its alot more responsive now as well as better economy. The stock HE351 Ve is a weak spot and it is recommended to replace when upping the power. If you are running a stock or lightly modded truck, you should be fine. Im limiting the boost to 30 pounds before defuel, may bump to 32 if needed. They do make a waste gate for it but due to design and mounting considerations your truck has to be deleted to install one.
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2012 RAM 2500 Laramie, Crew cab, 6.7 Cummins, 4x4, Bright Black, 35 Nitto Terra grappler, muffler delete,
Mini Maxx .38 mild

2006 RAM 2500 Big Horn,Quad cab, 5.9 Cummins, 4x4, Brilliant Black, Superchips, 35 Falken Wild Peak (gone)
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Old 11-29-2016, 07:57 PM
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My old '96 with 3:54 gears is actually pretty 'long legged'. I was gaining on a guy that had an '06 (the same guy I got my rims from) when he said he was up against his speed limiter at 107 MHP. I let out of it because I wanted to turn, but was impressed that my old 12 valve could run like that! Anyhow, that 23 mpg was one tankful. You need to remember that my truck is also a two wheel drive, so I am not turning other gears and things.
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1996 RAM "Custom Ground" 100 plate 3/4 forward, 300 injectors, 16.5° timing, Goerends Auto = 365HP, 833TQ Third Gen Rims, Aluminum Headache Rack
Duct Tape can't fix stupid, BUT it can muffle the sound
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Old 11-29-2016, 08:18 PM
Tiger Tiger is offline
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Gotcha. I dont think the 4x4 hardware makes a huge difference. Mabe 2 mpg. My 06 would get 21 hwy at 65. The 35s on my 2012 may be costing 1 or 2 mpg but the truck rides better with them on.
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2012 RAM 2500 Laramie, Crew cab, 6.7 Cummins, 4x4, Bright Black, 35 Nitto Terra grappler, muffler delete,
Mini Maxx .38 mild

2006 RAM 2500 Big Horn,Quad cab, 5.9 Cummins, 4x4, Brilliant Black, Superchips, 35 Falken Wild Peak (gone)
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