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'14 Overland
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Discussion Starter #1 (Edited)
Hello all, I installed the ECU on 05/22 and I have filled up after going through the first tank of fuel. I will update after the second tank.

Edit 06/10: This is the hot tune.

First I will start with the bad as there is only one item to discuss. That’s the lack of an OBD flash tool to upload the tune. At this time the only option is to swap out the ECU. The swap is easy, consisting of three bolts holding in the ECU plus the wire harness connector. Now the upside. I noticed the engine and exhaust note are now deeper in sound. No louder, just more throaty. My unicorn now sounds like an angry sewing machine. With the extra power of the tune the engine stays in high gear more before needing to downshift. I had that awful TSB flash that both Raven and ExcursionDiesel complained about where the Jeep would downshift all the time on hills. That is gone with the tune. In slow speed traffic the Jeep isn’t in a race to upshift as fast as before which leads to a smoother drive creeping between close stops signs and traffic lights. The power increase is very noticeable. I tried to evaluate this whole tank of fuel for mileage but I couldn’t help myself and I’ve been getting on the throttle a bit. From a dead stop 60MPH comes up very fast. I would say the GDE claims of minus 2 seconds to 60MPH on the Ram also applies to the Jeep. I dropped the Jeep into Sport mode yesterday and from a 20 MPH roll the tires let out a little chirp when I nailed it. The Jeep is extremely fun to drive now. Overall I'm pleased with the tube for the increased mileage and power. Throw in the reduction of DPF regens, lower DEF dosing, and reduced EGR maybe the emissions will last now.

For the first tank I logged 576.8 miles and filled up with 20.72 gallons which returned 27.84 MPG. This is all city driving. I have had to change my daily drive into work due to road construction. I now drive 18 miles each way with 2 stops signs and 18 traffic lights and go through two school zones. Previously I drove 11 miles to work with 4 stop signs and 5 traffic lights and I averaged 24.5 – 25.5 MPH on those commutes. I think 28 MPH is in easy reach and maybe even 30 on my old commute resumes once Michigan’s second season (construction) ends.
 

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Thanks for the info! I was wondering if they have a free upgrade option that allows users to update the flash as new GDE tweaks come out - or if the dealer happens to flash it with a stock program while doing a TSB or similar.
 

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Thanks for the info! I was wondering if they have a free upgrade option that allows users to update the flash as new GDE tweaks come out - or if the dealer happens to flash it with a stock program while doing a TSB or similar.
If you lose the tune due to dealer reflash, we will setup a new clone for $100. Ideally, just tell the dealer you are happy the way the Jeep runs and do not want any service updates. You can also get a lockable cover for the OBD port for a service visit.

Thanks
GDE
 

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Did you get the engine braking option? Curious as to how that works, is it something that is on all the time or is there a set of criteria that must be met? Really want to get a tune for my Summit when I pick it up on the 22nd this month!
 

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Did you get the engine braking option? Curious as to how that works
I'm interested as well, though I admit I question whether I would want it. I have never had another vehicle besides my EcoDiesel that required power from the accelerator in order to avoid slowing down while going *down* a parking ramp (I just shift to N now to avoid that).

It just seems incongruous to have to burn more fuel to get the vehicle to do what gravity wants anyway. If the engine braking is more of the same then that would be a definite donotwant.
 

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I'm interested in this as well. I think engine braking is most relevant to those of us who tow. Allowing the engine to slow the vehicle during coast helps preserve the brakes which is particularly important when going downhill and getting pushed by a trailer. Not sure if engine braking is as important to people who don't tow or live in the mountains. I read somewhere that unlike gas engines, which automatically provide some degree of engine braking when you back off the throttle, diesels provide almost none even when downshifting unless specially configured to do so. That's why our vehicles coast really well in stock tune. Check it out next time you drive. It takes a long time for the vehicle to stop without brakes.


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That's why our vehicles coast really well in stock tune. Check it out next time you drive. It takes a long time for the vehicle to stop without brakes.
Uh, not my 4x4 EcoDiesel. This vehicle downshifts rapidly when the accelerator is released and if you want to get any coasting distance at all you need to shift into neutral. Otherwise, it loses speed so quickly you would be lucky to be able to coast to the stoplight at the end of the offramp if you release the accelerator at the moment you exit the highway.

Maybe I need to disable Eco mode or something in order to turn off the "sucks at coasting unless it's in neutral".
 

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My 4x4 coasts well in Eco mode. I was trying to reset one of the emissions monitors after my cat was replaced by allowing the vehicle to coast to a stop and had difficulty finding a stretch of road long enough.


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'14 Overland
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Discussion Starter #12
I've never had any excessive engine breaking in either the stock tune or the GDE tune. I have a couple steep hills I drive daily and I let of the throttle before I start the descent and I have to hit the brakes well before the bottom as I'm increasing speed and running up on the people in front of me. I run Eco mode all the time.
 

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My previous WK CRD had significant slowing during coasting and I assumed it was a mix of stock tune and the DPF getting close to clogged - which I assume was creating back pressure which the engine could not expel the exhaust as well when coasting and using no fuel. After I did a DPF delete and the GDE tune on it and it coasted like a boss after that.

For WK2 owners - put it in sport mode is what I do when I tow so it holds gears longer and you get better gearing when doing down hills so you don't have to use the brakes as much. I use sport mode when driving locally as we have some big mountains and it helps going down hill so I don't wind up dragging the brake for a long distance (cops hide out at bottom of the hills unfortunately here in NJ).
 

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I've never had any excessive engine breaking in either the stock tune or the GDE tune. I have a couple steep hills I drive daily and I let of the throttle before I start the descent and I have to hit the brakes well before the bottom as I'm increasing speed and running up on the people in front of me. I run Eco mode all the time.
Your tune does not have the engine braking enabled. We added this feature with the production release as we wanted to make a trip to Colorado to validate it.
 

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Can you comment a little on what you are changing to provide engine braking, I know on bigger trucks there is a specific component to increase exhaust pressure for braking.

Are you adjusting the variable vanes in the turbo or something else to provide the exhaust pressure?

Also, how does the transmission handle this since it is not changed?
 

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From GDE with regards to the engine braking option:

"It will only be active in gears 3-6 and rpm 2300-4000 at zero throttle. In this manner it is not active in normal driving and typically only going down hills."
 

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I need to correct myself on the engine braking feature.

It is active in gears 1-6 with zero fuel when the rpm is above 2750 at sea level. At altitude 5000 feet and above, it is active above 2500 rpm at zero fuel in gears 1-6.

Most folks will downshift out of gears 7 and 8 on hills due to runaway issues. In cruise control, the transmission automatically downshifts descending hills if you are exceeding the set point speed. Once you downshift and get above the rpm threshold, the engine braking will be active.

Engine braking is accomplished by closing the turbo vanes to just below the backpressure limit to prevent turbo over speeding. There are no effects on the transmission itself, it would be the same as using your brakes.
 

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My previous WK CRD had significant slowing during coasting and I assumed it was a mix of stock tune and the DPF getting close to clogged - which I assume was creating back pressure which the engine could not expel the exhaust as well when coasting and using no fuel. After I did a DPF delete and the GDE tune on it and it coasted like a boss after that.
Hm, that's interesting and plausible. However, my EcoDiesel still sucks at coasting while in gear even when the DPF soot level reads ~10% immediately post-regen (i.e. a normal post-burnoff value).

Are there any plans for a future GDE tune for the EcoDiesel that would support DPF/SCR delete?
 

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Hm, that's interesting and plausible. However, my EcoDiesel still sucks at coasting while in gear even when the DPF soot level reads ~10% immediately post-regen (i.e. a normal post-burnoff value).

Are there any plans for a future GDE tune for the EcoDiesel that would support DPF/SCR delete?
Based on our testing, there is not a real need for dpf or scr delete. The tune we have reduces regen intervals substantially. Maybe as the vehicles age it might become a selling feature. Rather than spend $3000 to replace a dpf, remove it at that time.

Removing that hardware does nothing for performance as the turbo then becomes mismatched to the backpressure. Ideally you would want a different A/R ratio on the turbo if there is no downstream pressure drop.
 

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Based on our testing, there is not a real need for dpf or scr delete.
It makes sense that the EcoDiesel system is designed to expect the inclusion of the performance- & economy-robbing DPF backpressure. Bummer.

However, simply deleting SCR *operational aspect* like you have deleted EGR would seem to be a valuable addition, if only due to reduced headaches. No more "200 miles until no restart" crap thanks to clogged/snapped injectors, no irritation from cacked SCR catalysts, no more paying attention to DEF manufacture dates and crystalline contamination, etc. Would it be possible to simply disable the SCR/DEF injection and monitoring via firmware, thus virtually leaving us with a "DPF but no SCR" EcoDiesel equivalent to what our friends in Australia have?
 
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