Its been quite a while since I've updated this thread. Partly because I wanted to have something significant to update. Partly because I have needed to do some other things to the truck. Since I finally took the time to install the pyrometer probe in the exhaust manifold yesterday, and was able to get everything working properly today (I'm using a very old Autometer EGT gauge,) I was able to do some testing.
The tunes have evolved a bit since my last post. I've done significant work to the transmission functions, as performance wise I was already very happy. So the first thing I worked on was the shift schedule. Stock the truck shifts into overdrive and locks the converter rather late. Being an Early 1999 model truck, the transmission portion of the tune is not nearly as sophisticated as the later 7.3/4R100 trucks. But that doesn't seem to be an issue now. I took quite a lot of time and worked through the transmission section extensively. Shift pressure and shift schedule were completely revamped, as was the torque converter lockup schedule. After about two dozen minor changes and driving tests, I finally reached the current settings.
The results are fantastic. The truck can be driven any way you like, meaning you can put around in it like you have not a hurry in you, or you can drive it like you stole it, and it's perfectly happy anywhere between the two extremes.
So driving it like you stole it, this thing gets with the program. It has no issue getting up to freeway speed on even the shortest on-ramp. At the same time, smoke is modest, even minimal, and if you aggressively roll into the throttle rather than stab the throttle, there is minimal performance difference, but smoke is practically nonexistent. Once at speed, the transmission programming works well to minimize lugging and prevent smoke as well by downshifting when appropriate. The best part though has to be the EGTs. Testing on a 6% grade from 10-90mph generated a whopping 1150° peak exhaust temp.
For simple pleasurable operation, meaning you're not forced to rush, it's a wonderful smoke free experience that is still more responsive than stock by far. The biggest differences notable to this operating style is that by remapping throttle input, I've made the input more linear across the entire operating range, in fact, you could say it responds to pedal input more like a 6.0L, and that was what I was going for. This is where the efforts in transmission and torque converter operation really shine through though. Under moderate throttle, the transmission shifts at about 2000rpm and the torque converter locks up at about 1700rpm in third prior to the shift to overdrive. The entire driving experience is different from the original 1999 model and feels much more thought out and precise, almost like you are driving a later model truck like the 6.0L/5R110. Finally, EGTs at cruise run 550-625° from 55-75mph, so very pleased with everything.
Next up is testing the tow tuning.
The Current Truck (Oct-2013 to Present):
1999 (Early) F-350 Lariat, CCLB, SRW, Black/Tan
7.3L Powerstroke, 4R100, 4x4, 3.73, 37x13.50-18s, '05 Axle Swap, 6" Fabtech lift, GTP38 "D66" turbo upgrade, SCT 4-position chip with custom tuning by me, Straight Piped 4" down pipe through 5" dual stacks, N-Fab full length triple steps, Pro-Tech cab guard and tool box, louvered 5th wheel gate, Hella 500 Fog and Driving lamps, much more to come...
The one I'll miss, (Mar-2009 to Jan-2014):
2000 Excursion XLT 4x4
6.8L V-10, 4R100, 4.30, 285/75-18, 271whp / 388wtq
The one I won't, (Jul-2005 to Sep-2012):
2005 F-350 XLT, CCLB, SRW, 4x4 FX4
6.0L PSD, ZF-6S650, 3.73, 35x12.5-18, 4.5" Lift