Before I get started, the tunes were NOT purchased from DP.


Out Truck is a 2000 7.3 PSD F 550 Fontaine. Stock except for 5 inch exhaust no muffler put on by previous owner. We ran an old superchips 1705 tuner on it. Decided to do some upgrades, for more towing power, especially on hills. The transmission needed some help too. We had it rebuilt last summer after a hard shift into overdrive broke it.

My wife tows heavy. Her truck ,trailer ,5 horses and gear crossed the scales at 34,000 lbs.
This year, I added a 6 liter trans cooler, Garrett 38R turbo and ordered an SCT with custom tunes.

The 3 tunes we have tried so far have not performed well. they all have similar problems. The last tune smokes, runs hot EGT's (1300 sustained towing),has no more usable power than the old 1705 superchips and, while it shifts better it still has a couple of quirks. (sudden downshifts at less then WOT making motor go to near red line) As we tow horses, we do not run around, foot on floor from takeoff. We will roll into WOT while climbing a hill.

The old superchips, while it did nothing for the transmission
worked reasonable well. EGT's were reasonable and only approached 1300 on a long hill in 110 degree weather.
I know we are going to lose some speed on hills. The other tunes still lost 20 mph on a hill that the old tuner and stock turbo would lose 20 or less. At this point, I would leave the old superchips tuner if it helped the transmission.

Should I give the writer of these tunes another shot to try and fix this? Am I expecting too much from this combo? I'm thinking it's time to move on to another tune writer.

 

How are you having the tunes created? On a dyno?

 

They are custom tunes sent via e mail. No dyno time or live tuning. I thought that it would be effective because I have a mostly stock setup and it is a tow only vehicle. I had very good luck getting this done for my 04 lightning .You would think the 7.3 would be a "done deal" by now.

 

We can get you setup with some tunes if you are interested.

Feel free to shoot me an e-mail or PM and we can talk about the best options for your needs.

 

It sounds like your tune is a one size fits all tune or a driveway tune, the changes are approximations of how your engine acts. There are many vehicles that have well known changes that apply to all vehicles. You'll benefit from a dyno tune with someone who knows how to tune

That being said, it sounds like the first chip you had on there had a good tune. Depending on the type, that chip can be read and that could be used as the base tune for any adjustments.