As some know, earlier this year I tore into my Excursion and swapped injectors and a 38r turbo, among some other repairs.

I hooked up the RV a couple weeks ago and was initially not very happy. Since then I've put about 700 miles towing from Sacramento to Salt Lake City. While things aren't perfect yet, I feel like I was a little too harsh in my original judgment.

EGTs are definitely down from what they were. They seem lower on both flat ground and pulling hills, although I did have to drop it into 2nd 3 or 4 times to climb steeper grades. Note that I'm also pretty overweight on this trip because I'm moving and taking all my stuff with me. According to Cat, I'm at a little over 19k gross. So I'm sure that has a lot to do with not maintaining 60 on every mountain climb.

It does stay in overdrive on flat level ground, but only if I'm manually applying the throttle. If I'm using the cruise control, it hunts between third and fourth. I can sometimes get it to stay in overdrive on flat level ground but it requires a lot of babying the throttle to get it there. It seems that when the cruise control is first activated, it lets the speed drop a little bit. If I set it at 65, it drops to 64 before it engages. It applies too much throttle and it drops into 3rd. Then it hits 65, shifts to OD, and drops down to 64. Then it drops into 3rd again and the cycle repeats. It did this to me on a downhill grade today. I'm really not happy with gearhead on this and they have refused to answer my emails.

If I turn the cruise off, it's fine. No hunting.

Other than that, the truck hasn't missed a beat. It just runs and runs and runs.

 

That sounds good, thanks for that information. I have the same problem with my CC but I don't tow too often so it's not as bad as your experience. It drives like my father used to and could make a queasy person sea sick (slight exaggeration). I do/did not think that it's a problem with my truck, I think it's the way they are, if someone has information to the contrary I'd like to hear it.

 

At ~17,500 lbs my cc does not hunt on the flats and certainly not downhill. I have no tunes on the truck.


I had one case where the truck was dropping out of OD on the flats and being a gutless wuss on on the smallest hills. I changed the fuel filter (it had 3-4K miles on it) and that seemed to fix the problem.


I also end up in 2nd gear on some long steep grades. For example we were recently on the "circle" made up of 81, 77, and 64 in Virginia / West Virginia. On 81 we were able to maintain speed but on 77/64 we ended up in 2nd gear a few times.

I wish it were possible to see road maps color coded by road grade.....

 

Andy, good to hear that you are "happier" with what was done. One of the things I despise in this world is taking time and effort to make something better, then it turns out worse.

I look forward to hearing about your journey to fix your shift points and/or getting the transmission to act the way you would like.

Can you give us some rough numbers as to how much your EGT's are down?

 

I would say EGTs are down on average 100 to 150. I haven't pulled in over a year so it's a little hazy.

I tried to figure out my tongue weight but couldn't find a calculator and I know it's not super straight forward. Can someone run these numbers and see what my tongue weight is? Thank you in advance!

Loaded: 3840 7160 8160 (steer drive trailer)
No WDH: 3620 7460 8060
Truck: 4280 5380

Yeah I know I'm over. But it's a

 

That is a pretty significant drop in EGT temperatures. Now if you can get your transmission sorted out, you will be good to go.

 

Tongue weight is 1320. It's { truck no wd } - { truck alone }.

If you look at the WD vs the truck alone you see that your front end is lightened up by 360 lbs and the rear gains 2860. With NO wd the front is lightened up by 580. So the WD is restoring 220 lbs to the front end. Ideally you want to restore between 50 and 100 percent. So ideally restore between 290 and 580 lbs. Never more that 100%.

If you want to tweak it:

On a flat surface you can measure the front fender height on both sides with nothing hooked up. Then hook up trailer and WD. Adjust WD so the front goes back to the unhooked height or slightly higher. Never lower. Once you set it up via measuring fender height (at the center of the front wheels) you can double check at the scales.

 

Thanks Mike... I think I'm going to unload it from moving before I do any tweaking. The reason it's so heavy is because I'm moving so everything is packed to the rafters. I can't fit another box in my Excursion if I wanted to. I normally never travel this heavy.

So I have a bunch more thoughts on this I've collected while I was driving the last couple of days. I guess this would be a good time to let you know that I'm moving to the east coast (SC) to help my folks out for a bit. I left Wednesday afternoon.

First, I'm really, really happy with the power level and EGTs when climbing grades. The power this truck has now is unreal. I'm running about 2500 lbs heavier than I normally am with the RV, and while there were a few grades in the Rockies that slowed me down a bit, I haven't hit one grade that I haven't been able to maintain speed on since western Colorado (I'm in Herrin IL right now visiting a friend). This thing just eats up hills. Many grades I can pull in overdrive without loosing speed. The EGTs might climb up to 1100 or 1150. If they get much higher, I drop it into 3rd, and the temps drop right down. If I do have to downshift, it pulls it in 3rd at about 1050 or MAYBE 1100 if it's steep.

I've also been running at between 65 and 67 on the speedometer, which is 2-3 lower than actual due to the 285s. The truck is perfectly happy pulling grades at that speed (and faster). EGTs just aren't an issue any longer on flat ground (one reason I tried to keep the speed to 60 in the past). So my EGTs are generally lower by 100* or more, I'm loaded heavier, and I'm driving 5-7 MPH faster than I did last year. I'd say those were some pretty good upgrades.

I spent about 6 hours on Saturday driving through western Kansas in a 30-40 mph head and cross wind of variable direction. The wind hardly touched it. It barely swayed at all. I had to stay on top of it to keep it in the lane, but I continue to be very impressed by the way this truck handles the camper. It feels very safe and stable going down the road. The headwind caused me to put it in 3rd gear and leave it there for hours though. That tank of fuel did not last long.

I really wish I had about 6 more gears in this transmission. Four is just not enough. It sucks being stuck in 2nd or 3rd gear, knowing you could be in the next gear if it weren't so far away.

Cruise control is just not a good idea when towing. It's too sensitive and reacts too slowly to speed changes. It causes a TON of extra downshifts so I haven't been using it. I remember using it frequently last year but it's a no-go now.

I've noticed that when climbing a steep grade in 3rd gear and I'm limited by EGTs, I can only make about 22 or 23 lbs of boost. I can make more boost but then it runs too hot. Is this a difference between a 38 and a 38R?

I've also noticed that the power band seems to be a lot higher in the RPM range. It really doesn't like pulling below 1900 RPMs or so. It requires a lot of throttle and EGTs get pretty high. If I'm going through a construction zone at anything under 57 or 58, it hunts CONSTANTLY even with the cruise off if I don't lock it in 3rd. I think this is probably an artifact of the inefficiency of larger nozzles at lower RPMs if I had to guess.

The gas buddy app on my phone is a huge money saver. I filled up yesterday for 2.29 a gallon by driving 5 miles off the interstate. Pilot and flying J were getting 2.59 or more. I saved $13 or $14 on that fill-up alone.

I hear that 38R sing to me in my head when I lay in bed at night. But the S&B clearly has it beat as far as volume goes. It positively roars and drowns out the turbo when climbing at high RPMs under heavy throttle.

 

Sounds like it is getting better. Glad it is working out. Have you had to retighten the clamp form the up pipe collector to turbo? I just tightened mine up. For some reason it takes a couple times after I have it apart to "settle in".

 

Where in SC you migrating to?

I am glad you are happy with the engine and the performance from it. Although, as you said it sounds like you have some transmission tweaking to sort out. Those are great numbers for towing heavy.

 

Yeah, where in SC are you moving to? Would love to have another FTE family member close by. There are a couple of us here in Lexington County (West of Columbia).

 

I'm moving to Florence. It's pretty country.

That's a good tip on the turbo clamp. I never looked at it again after I put it back together.

 

Been through there many, many times on my way from Greenville, SC (where I was stationed for 7 years) to Ft. Bragg, NC. Welcome to our neck of the woods, glad to have you with us.

Bob, there are a few of us south of the GA border as well. I know of 4 in the "local" area if you include myself. Then another in the Anderson, SC area.

Off topic Andy, sorry... travel safe.

 

Yeah keep your friendly conversation out of my threads!



Let me know when the next get together is. First round's on me!

 

Another question... do high elevations contribute to high EGTs? When I was crossing Vail and Loveland passes, I was in 2nd gear doing 40 or 45 and held back by EGTs. Big trucks were crawling along at 10-15 MPH. I have a hard time judging flat ground or how steep a grade really is so I'm not sure if it's because the passes are so steep out there or if the elevation had more to do with it.

I almost had to slow down on a steep grade on I-40 between Knoxville and Nashville today. Almost.