EcoD Engine Braking

[JTdiRtyD]

Just got home from a 3100 mile trip pulling our ~2k lb camper. While everything went fine, I found the engine braking while descending down steep grades a bit lacking. Previous vehicles I was always able to find a gear that would hold speed fairly well without running too high rpm and with little need to touch the brakes even on long 7% or steeper grades, but the Gladi it seemed like I was always gaining speed too fast.

I thought I had read somewhere that the EcoD has it's own version of engine/exhaust braking by adjusting the vanes in the turbo? If so, I don't know that I noticed it, at least not when running in manual mode. The only time I noticed something was in the Black Hills on a 6% grade, I stayed in D and I noticed it downshifted to 7th and held 48ish mph on its own pretty well. This surprised me as my thoughts were 7th should be too high to really do anything, but it seemed to be fine.

Is the "engine braking" only while in Drive? Seems silly to me.

Other thoughts, there are some aftermarket exhaust brake kits that are reasonably priced. Not sure how well these work or if they get loud. I don't feel like for sub 3k lb camper we should need an exhaust brake, but I was having to use far more brake pedal than I'd like on this trip.

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[JT Diesel]

Just got home from a 3100 mile trip pulling our ~2k lb camper. While everything went fine, I found the engine braking while descending down steep grades a bit lacking. Previous vehicles I was always able to find a gear that would hold speed fairly well without running too high rpm and with little need to touch the brakes even on long 7% or steeper grades, but the Gladi it seemed like I was always gaining speed too fast.

I thought I had read somewhere that the EcoD has it's own version of engine/exhaust braking by adjusting the vanes in the turbo? If so, I don't know that I noticed it, at least not when running in manual mode. The only time I noticed something was in the Black Hills on a 6% grade, I stayed in D and I noticed it downshifted to 7th and held 48ish mph on its own pretty well. This surprised me as my thoughts were 7th should be too high to really do anything, but it seemed to be fine.

Is the "engine braking" only while in Drive? Seems silly to me.

Other thoughts, there are some aftermarket exhaust brake kits that are reasonably priced. Not sure how well these work or if they get loud. I don't feel like for sub 3k lb camper we should need an exhaust brake, but I was having to use far more brake pedal than I'd like on this trip.

I use the manual mode to engine brake when going downhill, and have found this to be quite effective. In my experience, the transmission will hold the selected gear even when I move the transmission back to "D", and will upshift when I apply throttle pressure. I don't tow but I do have a bed canopy and rooftop tent, along with some gear in the bed that usually stays there (about 650 pounds total payload). I have almost 64k miles on my JTRD and this has helped preserve my brake pads and rotors well.

 

[brsnow2585]

I've kinda noticed this on mine too. I believe switching into manual mode overrides some normal things, because it's not really manual, it's a highest gear limiter. You can tell your 8 speed, to only be a 5 or 6, but....I don't think the running on the transmission adapts from being an 8 to whatever number you set it at. I do use manual sometimes when I pull my camper, but more when I need to downshift to get a little more giddyup when the transmission doesn't want to

 

[JTdiRtyD]

I use the manual mode to engine brake when going downhill, and have found this to be quite effective. In my experience, the transmission will hold the selected gear even when I move the transmission back to "D", and will upshift when I apply throttle pressure. I don't tow but I do have a bed canopy and rooftop tent, along with some gear in the bed that usually stays there (about 650 pounds total payload). I have almost 64k miles on my JTRD and this has helped preserve my brake pads and rotors well.

I was using manual mode but it wasn't enough with the camper in tow. I didn't try switching back to D while descending, but I suspect it still wouldn't be enough.

I've kinda noticed this on mine too. I believe switching into manual mode overrides some normal things, because it's not really manual, it's a highest gear limiter. You can tell your 8 speed, to only be a 5 or 6, but....I don't think the running on the transmission adapts from being an 8 to whatever number you set it at. I do use manual sometimes when I pull my camper, but more when I need to downshift to get a little more giddyup when the transmission doesn't want to

I know GDE offers an engine braking option with their tune that closes the vanes in the turbo and I've been told works pretty well. I reached out to EOC to see if their towing tunes offer the same.

Otherwise I did find this which could be promising, but requires a diesel diet to work.

https://us.bddiesel.com/products/bd-exhaust-brake-universial-install?variant=30073622593600

 

[Jrgunn5150]

Mine (Ram) was tuned for so long I forgot what it drove like stock.

But with the MR Tuning, it would hold speed downhill no problems with 7-9k behind it.

 

[brsnow2585]

I think my camper is about that same weight. Do you have trailer breaks and a controller? I pulled my camper without first, it was kinda like you said. Got the OEM Mopar brake controller, pretty much plug and play, so much better

 

[rharr]

The EcoD has a exhaust brake installed. There is a butterfly valve behind the DPF that opens and closes to modulate back pressure.

 

[DylanM]

The trick that seems to get engine braking to work on my truck is to get on the brakes firmly for a full second or two then let off. Not sure if it's a certain accelerometer threshold that must be met, but without the firm brake application first it'll just merrily coast downhill to ludicrous speed, whereas after the firm brake application you can feel the engine braking take effect and the transmission will shift differently. Applying throttle to accelerate resets things back to normal.

 

[JTdiRtyD]

The EcoD has a exhaust brake installed. There is a butterfly valve behind the DPF that opens and closes to modulate back pressure.

Any documentation on this? I read the EcoD did not get an exhaust brake in any platform.

I think my camper is about that same weight. Do you have trailer breaks and a controller? I pulled my camper without first, it was kinda like you said. Got the OEM Mopar brake controller, pretty much plug and play, so much better

It does not, but trailer brakes shouldn't be controlling your speed down steep grades or you'll overheat them.

 

[rharr]

Any documentation on this? I read the EcoD did not get an exhaust brake in any platform.

Yes, climb under there and look at it, watch it actuatue on shut down. It opens and closes on shut down to keep it free and moving.

It's no jake brake but it will it improves engine braking since diesels aren't big on engine breaking without help.

If you hit the right conditions the computer will activate the exhaust break and give you little more decent control on long grades so you aren't riding your brakes as much.

Usually involves x amount of time at higher rpms going down hill without hitting the throttle and modulating the break. Well that's how mine works and like i said it's not a jake break, it is engine break plus like if you were driving a gas car and downshifted.

 

[JTdiRtyD]

Yes, climb under there and look at it, watch it actuatue on shut down. It opens and closes on shut down to keep it free and moving

Thats not for exhaust/engine braking, thats to create backpressure so that air will flow up the post-DPF EGR pipe.

 

[rharr]

Thats not for exhaust/engine braking, thats to create backpressure so that air will flow up the post-DPF EGR pipe.

I believe it does both. I added to my comment above

 

[brsnow2585]

The trick that seems to get engine braking to work on my truck is to get on the brakes firmly for a full second or two then let off. Not sure if it's a certain accelerometer threshold that must be met, but without the firm brake application first it'll just merrily coast downhill to ludicrous speed, whereas after the firm brake application you can feel the engine braking take effect and the transmission will shift differently. Applying throttle to accelerate resets things back to normal.

You got what was stuck in my head, kinda same as most people's daily driving habit, which I don't subscribe to. Unloaded, I let off coming up to a stop, not running up hard and just breaking. The 8 speed does naturally brake as I said, but if you do poke it, it gets out of brake easily. If you add a load behind it's more sensitive. The brake controller was by far the biggest and least expensive/complicated addition that made towing my camper less stressful. If the trailer has brakes, let it help when you touch the brake pedal. It's more efficient to pull than push, it's a little obtuse, but think about it like the Dr Doolittle push me pull you

 

[Desert_Gladiator]

When you buy the GDE Tune, there's an option for engine braking that can be added to your tune at an extra fee. Their description for the feature is: "Closes vanes on turbo to increase pumping loses to help slow down. Manually downshift to have rpm above 2500 and foot off accel pedal to activate."

I got that with my tune, and can't say I can really tell the difference. I'd describe the engine braking as 'barely adequate' even when not towing. I'd say, even when using that feature, the JTRD has the weakest engine braking of any vehicle currently in the driveway/garage (of 6).

...Which is odd to me, because with all the diesel compression, I'd think there's plenty of potential for some very strong engine braking.

 

[Vtur]

Mine works best in D and in lower rpm range compared to manual mode.

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