It always worth it to do the trutrac over the factory limited slip. Whether you tow regularly or just daily drive unloaded you can't go wrong because it won't break and it won't let you down.

My 3.73 geared '05 Excursion hasn't pulled a heavy load up a steep grade but I could see how 4.10s would make a difference. Out of all the diesels produced over the years, the 6.0 was the ONLY engine that worked at its torque peak, 2000 RPMs.The 7.3 made its power at 1600 rpm's and no one cruised at 55 mph towing. The same went and apparently still goes for the Duramax and Cummins.

 

Please explain the positives and/or the negatives of this comment.

 

My truck has larger injectors so I got an as close to stock tune made for me by pcdtuning.com and it's roughly 40-50hp over stock and pulls very well and shift points are nice and crisp/smooth. Should also mention that I have 2 other hot tunes from the same company and they are all excellent tunes and the PCD people are awesome and helpful so if you want a tow tune they can write one with overdrive lockout and earlier fan activation etc etc and you can request no power increase if you want or bump up 40-60hp.

Towing 15,000lbs you 100% need an EGT probe, blue wire mod or earlier fan activation via tuning and make sure to keep an extra IPR and ICP with you and absolute BEST BEST BEST washer fluid to get bugs off is just water with a good helping of Dawn platinum dish soap and it's only a few cents per jug compared to how many dollars for the store bought crap that doesn't clean anything! Also clean your windshield with a good product then wax it and buff clean and that with the Dawn will give you crystal clear glass even when up against the nastiest of bug splats.

 

The low RPM torque peak gets the load moving but the peak torque at 2000 rpm's on a 6.0 keeps the load moving. Other diesels at the time were past their torque peak at cruising speeds which more often than not meant 2000-2100 rpm's at 70-75 mph. At that same 2000-2100 rpm's, the 6.0 was working hard but it really wasn't because that's where its torque peak was. This is why people got 20-25 mpg freeway unloaded (no lie) when these trucks were brand new back in 2003. This is also why the 6.0 shined in the higher rpm's when you had to climb a steep grade.

With the torque peak so high on a 6.0, wouldn't that make it harder to get things moving?

Ford/Navistar thought of that and that's why it was probably the first of its kind to have a VGT turbo and the transmission that it does. The two work well together to not only get the load moving, keep it moving, but also bring the load to a stop.

The only downside is how they robbed the engine of power and capability as they went further along in production. The 2003 trucks had the largest compressor at 59mm and by the end of production the compressor shrank to 55mm. The turbine shrank mid 2004 before the 2005 MY. The same went for the later flashes, the early VXCF4 family of flashes proved to be the most potent for the 2005-2007 trucks while the VXCF9 flashes offered less power and sloppy, sometimes, lazy shifting and tow haul.

Bottom line: it's a solid towing platform and one I'd trust any day to haul a heavy load across the country.

 

The '03s also seemed to be better at low-end torque due to the different camshaft design. With the '03 cam, I had an easier time breaking the rear wheels loose at a moderately aggressive throttle, along with some darker smoke. The stage 2 cam doesn't do that at all; same programming.

So, the low end is better with the cam, and the high end is better with the turbo.

 

So if I ever need a new Turbo, I should consider a larger one?

 

I have noticed a difference between my current ‘06 and my old ‘04. I don’t know what strategy my ‘04 was running, but was stock except egr delete. It was very good on fuel for a srw F350. It hauled a lot of loads/trailers east to west across country with it, and into the upper States with it. It was always reliable, and pulled very well. (It was new then too, gone for a decade or so now.)

My ‘06 is running VXCF9H7, very different feel of power, shifts, and most notably - it is not as good as my ‘04 was on fuel.

 

Thanks for that TD! My strategy (from the factory) is VXCF4X3 and truck is a 7/2006 build - based on Jeff's post above, does that mean the VXCF9 strategies were earlier?

 

Careful what you wish for. I have the KC Stage II (original version) and although it is great at top end it does not like to lug at 1250 and below. The programming cleans up my 175/30's and it pulls great once the air starts moving through the system. with excellent EGT's. My EGT's will hit 1450 if I am not watching my RPM's closely while towing and it pops into the higher gear.

Last I spoke to Charlie, I asked him about his new jetfire versions and with what I told him, he recommended the Stage 1 which I was thrown back by. I am guessing he has revolutionized the turbo world again and these new jetfire are it.

I never followed through because my truck is just great as it is. I guess if I towed alot I'd consider it.

 

Another key difference, that's why I was trying to hunt one of those down before I got my engine back together. It's still out of the truck so I may still do it IF I can find one in good shape.

The KC 61mm turbo will serve you well towing or tuned. Not too big but not too small either. Plenty of air throughout the RPM range.

Those 2004 trucks were some hard running trucks too. I remember folks with an F350 reporting surprisingly good mileage for a truck that big.

They do need some tuning to firm things up but it's never the same as a stock early VXCF4 strategy.

You have the highly sought after YJZ1 it's a more refined version of YJZ0 that pulls hard and shifts well. The only caveat to YJZ1 is that it DOES NOT play well with the Atlas 40, it's very smoky even stock. It prefers the company of AMZ2AL12 Enjoy

 

My Jan 06 build truck shows a VXCF4H2 strategy which I"m guessing is the original. Is that any good? Is there any way to get one of the "really good" VXCF4 strategies? I've tried searching for info on the various stock strategies and never found a good "guide".

FICM has the original, non-inductive strategy as well.

 

Bill at Power Hungry rolled my strategy back to VXAM7N2 years ago, no idea if he is still doing that, but might be worth a call. https://gopowerhungry.com/

 

He also appears to be on LinkedIn:

https://www.linkedin.com/in/billcohron

 

FICM Repair rolled mine back to that strategy, but I have no noticeable power or mileage change since doing it, though it is nice to have the ability to read EBP pids, and I have no more CEL for the delete, so there is that.

 

Some great insight. I’m guessing that’s why the manual trans like mine was very doggy off the line and the reason for the super low 1 “granny” gear. That was the one thing that kind of annoyed me about the manual. You really had to learn the clutch and shift points. I have had several peopIe offer to pull my boat up the ramp for me and they stall the truck so many times that I have to climb out the boat and do it. I have to say though, after a few upgrades specifically the Atlas 40 and KC turbo 10/11 blade single plane wheel, the low end rpm off the line is much better. Also to your point, the EGTs are so much hotter if you’re ******* it up a hill at 1400 to 1500 than keeping it in the 2000 rpm sweet spot. Even when downshifting doesn’t seem necessary, keeping it in the 2000 rpm range really helps with the egts.