The Ecoboost isn't carbureted so why are you even talking about it? It's EFI so I was explaining how EFI works, NOT carburetors. I grew up with them, I know how they work, they just aren't relevant to this thread though so I'm not going to waste my time talking about them

 

Because your statement is self limiting in regards to blown motors. Since blown motors do not require EFI to run, studying EFI is pointless. What would be the point of someone studying EFI if the motor wasn't blown?

The Ecoboost is a direct injection motor. The rail pressure at its peak is 40 times higher than any EFI motor. Without direct injection there is no way Ford would run 10.0:1 compression. The injection on this motor has more in common with a diesel than a gasser. Should you have said, "More rpms does NOT always = more boost. Look into how DIRECT INJECTION works" ?

If someone really wanted to know how boost and rpm are related the first thing they should study is wastegate control and how it limits an overspeed/excessive boost condition.

The first blown motors I built had carburetors. The first blown EFI motor I built was a Mitsu G32B. I felt like a cave man discovering fire with that little Mitsu.

 

Wow, this is kinda like polictics and religion, some things you don't discuss out in the open....lololol..please enough already..

 

Does the EB come with a boost gauge? If not I think one might find it useful. Definitely will allow one to see the effect of RPMs and Boost.

Has anyone determined how much boost you can run and still make decent mileage?

 

Runs in vacuum while cruising, any load bumps it into boost & of course drops mileage.

 

I am well aware of that, but if you can keep your boost down while accelerating you mileage will improve. My question is what boost level do you want to stay under while accelerating or towing to help with fuel economy? I know with my PSD's I try to keep it under 10lbs while accelerating if I am trying to achieve good mileage. (not something I am usually patient enough to do)

 

The less boost the better, and the more vacuum, even better. Ultimately, you want to never hit boost (which I'm sure is impossible if towing) and always stay in the highest vacuum number as possible. A typical vehicle pulls around -4 to -6psi (-8 to -12 inHg.)

Basically, you want your vacuum numbers to be as large as possible, and IF you have to use boost (to get up a hill or while towing a load) the smallest boost number as possible. That, combined with lowest rpms is the key to good mileage. High vacuum + low RPMs (wherever that combo is at) will yield you the absolute best fuel mileage.

 

Any more info on the whole disabling the sway control system and fuel mileage?

 

As for the boost issue. I installed a boost gauge. I find that when cruising at 55 to 60 I am running about 4 to 6 inHg of vacuum.
Any boost at all and the instantaneous gauge starts to fall below what I am averaging (usually averaging around 20 at these speeds).
I have also found that you end up with a better mileage average if you accelerate at about 5 to 7 lbs of boost and get on up to speed in a relatively quick amount of time than trying to do a slow long acceleration at less than 5 lbs of boost.

I have not done a long trip yet with the boost gauge installed to find the majic speed at which boost/vacuum start to dramatically effect mileage. But in a very quick look on a short interstate run of about 5 miles in town it seemed to be about 68mph was the break point. I started at 74 and would bump the cruise down 1 mph about every 1/4 mile. Road is basically flat. Once I hit 68 instant mileage seemed to come up a little to about 20 mark and vacuum dropped down to about 4 inHg from basically 0.

My truck is 2011 Supercrew, 5.5 bed, ecoboost, 17k miles, 3.55 rear, 4x4.

 

Thermo, what boost guage did you go with and how did you mount it?

 

I purchased the GlowShift 7 color 30 psi Boost - 25 InHg vacuum gauge.
Do a google shopping search for Boost Gauge Glowshift and you will find it. I liked this one because it allowed you to select the color that best matches the dash lights (light blue in this case). And it will hold that setting. There are some other ones out there that just cycle thru all the colors so be careful if you look around on ebay and stuff.

I used the Roush Vent Gauge Pod to mount it. Works great and was easy to install. You can always remove and never know it was there. Again do a google shopping search and you will find the best price.

I did have to drill a small hole thru the firewall in order to run the boost/vacuum line. It was easy right next to the electrical wire bundle on the drivers side.

Wiring, I just ran the wires over to the fuze panel and put the wires in behind fuzes that were ignition and 12V and tied to ground there next to the fuze panel.

 

I found a disllike! Don't get stuck in the mud! I was out looking over a pipeline route and took a prairie trail that looked decent. After traveling about 500 yards I decided that it was gonna get a bit sloppy so I decided to turn around. Of course as I pulled into a grass area to make the turn the front driver side tire dropped, and the the rear driver side was sitting in the rut on the prairie trail. I found I could move about a foot forward or backward but couldn't get it to climb back up on top. The tires turned into to complete slicks and were all but worthless. To make matter worse, between the throttle by wire and the turbo lag I had a heck of a time trying to rock it. Since I could only move a foot and needed to go backwards, from the time I would stand on the go pedal to the time when it would actually wind up, I had already moved back a foot and was up against the ledge. It was like for the first second or so I had about 1% of the power and then it would kick in. I ended up having to power brake it inorder to build boost and get rid of the throttle lag and even then it still wasn't good! My other complaint is with the throttle by wire when you let off the go pedal it takes a second for it to notice this and quite building power. I noticed this before in the snow but it was really apparent when I was stuck.

I never did get out on my own power however I called my brother in law who brought down his 2012 Chevy 3500 Duramax. Well he ended up stuck before even making it half way down the prairie trail. I don't think he was in 2" of slime and that thing wouldn't move at all! We ended up doing a little shoveling, stuffing some wheat chaff under the tires and pushing his out. He gave us a ride back to town where I grabbed the ol F250 V10. No, as bad as my tires are on it I didn't even attempt it with the F250! I hooked up to the flatbed and took a tracked skidsteer out for the extraction!

Anyway, long story short, there is a massive lag in throttle reponse between the turbos and the throttle by wire that makes getting unstuck almost impossible! when driving it day to day I don't notice it very often but it was very apparent in this situation.

 

Thanks thomastl. That is really helpful.

 

Tagged for research. The eco is making me nervous. Maybe I should go with the 5.0.

 

5.0 if your not towing a large load (say over 5000 lbs). After that, the low end torque is amazing for towing.