The ecoboost is a small displacement motor and won't have as much engine breaking force as something with more rotational mass like the bigger motors you mentioned

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I agree. On our trip to Alaska pulling our ~6,500 lb TT with our 3.5 EB we encountered several long and steep descents, some up to 10% on the Alaska Highway. Very little engine braking and some high rpms a few times until I learned to start down slow and brake fairly hard to whoa it down 10-15 mph, then repeat as necessary.


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I guess that is where the hill descent assist comes in handy.

 

Hill Descent only works between 2 mph and 12 mph. I uses the brakes to control speed.

 

Have you tried any tow tunes?

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Not I'm still 100% stock but I was wondering if that would make a difference. I'm 500 miles from end of warranty so I might try that. I swear it feels like the throttle isn't closing all the way which a tune could change if that is in fact the case.

Without variable vanes or an exhaust brake I don't know if you can get much braking from the turbos? My 6.0 had the vanes and that made a HUGE difference in engine braking vs a 7.3L with the standard turbo. Still nothing like a true exhaust brake but you actually had some engine braking.

 

I always thought the thing would totally suck engine braking a trailer because of how little it does unloaded, but I found mine actually does pretty could. Obviously it could be better but I’ve never felt like I was going to annihilate the regular brakes on extended downhills. just a quick tap here and there. Generally it will hold a speed if not slow me down.

I have always wondered if someone could tune the earlier trucks to utilize the raptors anti lag mode. I assume what they are doing is opening the throttle body and closing the wastegates to keep the turbos spooled. Why not use that same function to use the turbos to add to the engine braking. Takes a lot of hp to drive turbos, it would just be anti-hp in this case.


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Easier to control the Gen 2's electronic wastegates vs Gen 1's vacuum actuated wg's.

 

It made a difference going down steep grades on my '16 2.7.

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@RoastinF150 has spoken on this matter from the perspective of one who can pull the strings. I think my tow tune did what it could with the motor, but also used the tranny well keeping her tidy.

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Your referring to the DFCO parameters. Stands for Deceleration Fuel Cut-Off. The factory tune is quite lazy with these and it does not cut fuel very often when off the throttle and coasting. This is easily changed in the tune. I have my DCFO much much more aggressive, which helps slowing down with and without towing something, preserves the brakes, and saves fuel. The reason the large OEM's do not chop the fuel right after your off the throttle is they want the vehicle to have as smooth of transients as possible when on and off the throttle. There are a lot of things baked into the tunes in every vehicle from the factory to try and make the vehicle behave as seamless as possible.

 

Since you're pretty deep into tuning, do you know if there's an adjustment table for the lag time when shifting from R to D, and D to R? It's the only thing that really annoys me.

 

I think the stock tune does a decent job if you let it rev 4k-5k. Not big v8 good but reasonable. I'm on the ESP so have been reluctant to tune.

 

It works up to 20mph

 

Should be able to reduce that in the transmission tune. Let me tinker with it and I will report back

 

I will have to look at some of my logs to see where duty cycle is. If it reasonably high then there may be room for this to function. The only way to hold higher rpm on decel is to be in manual shifting or to tune it into the auto shift tables. I have my trans downshift a little sooner on decel to hold higher rpm's when under DFCO just so I can stay in DFCO easier and use the engine friction torque to help with decel.

 

And tow/haul mode will kick down automatically with brake applications or if you have cruise control on.


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The very first time I pulled a trailer going downhill was a few years ago my 2014, and I was expecting the engine braking to really slow me going downhill. Boy was I wrong, and the wife and I could feel the trailer sliding out from behind us going down a turn. I learned real quick to really watch my speed going down and to not wholly rely on the engine braking. Now that I know how comfortable I am with the engine, I cycle between brakes, engine and trailer brakes and I'm pretty confident with the truck.

 

I've seen two different styles. One is just a single value for both the N-D and D-N transition. The other is a small function with N-D on one side and D-N on the other. For our trucks I'm only familiar with the single value version. I can look again later.

 

Thanks for looking. Right now whatever table Torrie changed, he's set the value to -20. I don't know how the values correlate to time, but it's def quicker in the D-N scenario.

 

Here's the stock values from my 2013:

Here's where I put them on an older tune (I think I changed them a bit more since):

You can see I did 3 things, enable and disable at lower vehicle speeds and lower engine speeds. And also make the ramp on rate to the maximum (8) which makes it enter decel very quickly (higher number here makes the transition faster). Last thing is to make the Delay Extended 0.

I think I have since made an adjustment to the N/V which is an arbitrary Ford value that is simply Engine Speed/Vehicle Speed, but also has clips, so the DFCO action WILL work with it at 0 still when it clips, but by increasing this it can get even more aggressive and the transition back to fueling can be jumpy. You can play with the Ramp Off value to smooth it.