Ok, I have some updates for the team.

First, on the EGT argumentatation: I was wrong, I had the warning set to 1400, not 1000. I've reset it to 1200 and we get warnings when the truck downshifts on hills, up to about 1250. We're going through the Chatanooga area, rolling hills, and for the most part it never sounds. I'm watching the driver now on a slight incline and EGT is around 1100--1150 in 4th with the TC locked, as high as 1400 in 3rd. On the flats we're cruising around 1000.
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Second, the wheels and tires. We installed 2017 Ford F-250 20" wheels and 275/65-20 Michelins using Motorsport Tech aluminum spacers. It has made a transformative difference. Towing this 34' 15k package.has changed from a 2-handed white-knuckle 55-60mph challenge to a single-handed comfy 70+ mph drive. I'm sitting here right now watchin the driver at 75 and occasionally asking him to back it down (we are, after all, pulling a 34' 15,000 trailer...)

Plus it looks really good.

Third, with the wheel tire change, the speedo is now off by 5 or so mph. That's not such a big deal except the DP Tuner is now downshifting more at an indicated 65 mph than it does at an indicated 70. That, of course, results in higher EGTs (trans temp is still in the 145-155 range). I've configured the Edge controller display to accomodate the bigger tires, and we have the GPS speedo, but the more-numerous shift huting is annoying. Anyone have any idea how I can get that adjusted?

Did that cover all outstanding questions/issues? I appreciate the feedback, keep it coming!

 

Sounds like it tows pretty good, there is no problem going 75 mph with a big trailer as long as the conditions are safe. Also downshifting and running at a higher rpm lowers your egts because you are getting more airflow in and out of the engine.

 

Contact Jody and have him adjust the tune for your new specs.

Stewart

 

 

My experience with my Ford diesel, including this one, has been the exact opposite: higher RPM makes the EGTs shoot skyward. EGTs stay low if it retain 4th and works harder.
Ack! Just bought it a few months ago, and it's not the USB-tunable one. I'd have to remove and ship it to him, and pay another fee..dammit...

 

That's odd, I usually go by the EGT gauge to see when I need to downshift, when It climbs above 1,200 I drop a gear and it either holds steady or drops down some.

 

Just to be clear we're talking about the same thing, I'm describing climbing a grade with steady throttle pedal. RPM is steady around 1900 or maybe declining slightly. EGTs will be roughly 900-1000 or so. However, if I retain that steady pedal and the ECU decides to downshift, the RPMs climb (duh) to around 2500 and the EGTs will immediately spike to 1200+. If at that point I decide to push the pedal in for more "go", the EGTs will continue to climb.

 

Yes that's the opposite of what mine does, I stay in overdrive untill my egts are getting too hot and I downshift and it brings the egts back down. On the interstate I would never have to downshift if the egts didn't get that high.

 

It's also the opposite of what mine does. If I'm climbing a slight grade and the EGTs are at 1150 or so, downshifting to third is typically good for about a 200* drop in EGTs. On flat ground, EGTs are around 950 or so and shifting into third doesn't change them much at all.

 

As 00t444e and Andy have posted, your truck, if you're describing the actions accurately, are not normal. Pulling a grade and having your speed drop, causing more pedal input, will increases your EGT's, but when the transmission kicks down out of OD, your EGT's should decrease, not increase. That's one of the reasons to push the OD button on the stalk, to take it out of OD and lower engine temps.

Sttewart

 

Well, I don't know what kind of funky alternative universe we're living in, but I know for a fact that EGTs climbed when the truck downshifted under load. Always has, both in this one and the prior Excursion, and regardless of what chip/program I'm using.

Climbing a hill and you tipped in the pedal to maintain speed and as the boost built up EGTs would remain steady or even drop. But if you continued to try to maintain speed then as soon as the engine downshifted the EGTs would start to climb, fast. In fact, the only time we hit the EGT warning was in a climb after the trans downshifted, which is why we spent effort to ensure it did not downshift, even if that meant letting the rig slow down.

I texted my co-drivers about it just now, and they confirmed it worked the same way with them as well: trans downshifts, EGTs went up.

 

It's not a funky alternative universe, there's something wrong with your truck. I'd start a new thread in the 7.3L and see if you can get some answers there.

 

There's nothing wrong with the truck, it runs fine. It just pulled a 15,000 pound trailer from Connecticut to Texas and back, without a hiccup, and got an average of 10.5mpg in the process (yay, DP Tuner!)

My prior Ex did the same thing for almost 300,000 miles.

Maybe you guys should get your truck checked out...

Edit: do you guys pull anything of significance? Maybe that's the difference. I use this truck exclusively for towing (it is, after all, a truck). Maybe I'll drive it to work next week and see if it acts any different.

 

It may run fine, but it sure doesn't act like any of my previous or current 7.3's.

Yes, a 10k, 31' travel-trailer and a 10k dump trailer.

Going up to Oregon from California, pulling the pass with my travel-trailer I got tired of my fan kicking on because my coolant temp would climb too high while in OD, even though I was able to just maintain speed, so I clicked off the OD button on the stalk to keep it out of overdrive, which keeps the engine oil and coolant temps lower in those conditions, not higher.

Kicking the OD button off is one of the standard practices to lower engine temps while pulling a grade, I dunno why that's the reverse for you, but what you describe is not normal.

Stewart

 

I made no declarations about "engine oil and coolant temps", I am speaking about EGTs only.

The only observations I made during the trip about "engine temps" is occasional checks and seeing TFT pretty solid at 148-156 (except when it got as low as a surprising 120 through the flats of Alabama with an OAT of 34), and the EOT almost always at 220 +/- 5, pretty much the whole round trip.

Thanks for the feedback, fellas, but there's no problems here.