Ok, we finally get everything squared away and my friend leaves on his cross country trip....He doesn't get more than 100 miles away and calls me on the cell.
He said that his new tune is allowing the EGT to hit 1500 and black smoke when the truck downshifts to go up a hill with the 5th wheel behind it! I don't think this is normal. 1200 is the highest that I have heard is safe. His "check engine" light is coming on also, never happened before.
This truck is an 02 F-350 with dually, crew-cab and 5th wheel, 33.5 foot, 12,500 gvw.
This truck has the Walker Resonator (straight through) no muffler, Drop in replacement air filter by AFE, new compressor side turbo housing, DP tune (60hp tow code tune)
We decided to leave the tune switch in stock until Jody calls on monday.
Any comments?

 

boost leak in the IC or Y pipe boots..or the babies butt didnt seal to the back of the turbo tight ...or you could have loosend the donuts when you put in a new wheel..look for black soot around the back of the turbo. or loose boot some place..

 

I don't know -- spiking the EGTs on a 60T tune with a 12.5k tow load up a hill doesn't sound unreasonable to me. I have spiked mine with the stock turbo over 1500 many times. Now with the van turbo, I barely get over 1200. And that's only when standing on the throttle well over 100 mph....

 

i hear ya Joe..after reading it again..i see he has a drop in AFE..must be a stock box ..with the new compressor side turbo housing..its not getting enough air...id do a 6637 if everything else looks good...would be a fast and easy mod just to make it safer..my set up lets me make the spedo point strait down before it hits 1250....gets there prety quick if i might add..

 

What is a 6637?
The boost is going right up to 25, if I remember correctly.
We had a "hot" side sleeve connector, up by the turbo, go bad. It had a 1 inch slit in it, so we replaced it before he left. We found this because we pressure tested the whole piping system and the intercooler. It held 10 psi for over an hour.
This truck has about 55,000 miles and is in nice condition.
We were going to change the exhaust system to a 4 inch, but decided to save a few dollars and only eliminate the muffler and keep the stock pipes.

 

More air in and more air out is usually one of the first things you want to do before adding a tuner. I'm not sure the muffler delete and drop in filter will be enough on it's own.

 

6637 is a napa wix air filter...we use a piece of 4" exhaust pipe to hook it up...

no such thing as saving $$ when moding these trucks..all mods are for a reason..you just found 2 that didnt really save you any thing...

 

6637 is a big air filter mod. here is a link with some pictures. first without petes cover sock and one with.. . https://www.ford-trucks.com/forums/8...-6637-mod.html

 

Before we put in the tune, I asked Jody what he thought about other mods. He did not think that we needed to go to a bigger exhaust or intake, other than the muffler and drop in filter.
Maybe this isn't quite the case?

 

Yep 0273 I would give it more air for sure put in the 6637. The 60hp tune and only a 12,500 load should not get that high.

 

The issue with the the exhaust is that it's 3.5" NON-mandrel bent. The muffler is the main restriction, but when you start really taxing the truck, I can see that being an issue. The 4" is mandrel bent and the muffler that goes in is usually a straight through type.

The problem with the stock intake is the box -- it's a big POS and lets dirt past it. Plus, I don't see how a drop-in will flow anything like this one:

 

I should have prefaced this discusion by saying that the ONLY reason we went through all this was to get better fuel mileage.
Power is not the issue. As long as the trailer gets there, that's all that matters.
If the tune is adding more fuel, how can the mileage be better? I would think that the injection timing curve would need to be modified....Does Jody do this?
If not, who does? Does it improve things?

 

How big of a mileage gain are you looking for? The simple math says that if the driving habits don't change, you will never see the return for any improvements you might see. He's got a 7 year old truck with 55,000 miles on it. You're not going to get a 10 - 15 mpg improvement, and it will take a long time to realize your expenses if you only see 1 - 2 mpg improvements.

Now if he starts driving a lot of miles in a year, you can look into things like an overdrive splitter to keep the engine in the proper rpm range on the hp/tq curve, but at less than 8,000 miles a year, he's better off just filling the tank and taking what the truck gives him.

At least in my opinion.