Not sure how many of you guys visit the SD forum but some of us got together and to compare a V10 (mine) vs 7.3, 6.0 and 6.4.

https://www.ford-trucks.com/forums/9...ith-video.html

 

Nice test - great post! Have you figured out what was going on with the shifting yet? Need to try this next time I have my boat hooked up to see what mine shifts at.

 

The v10 sounded strong but without the torque it was a loosing battle.

Nice real world test. :-)

 

Mike from 5 Star figured out it wasn't shifting into 2nd but instead it was the TC locking at 3,000RPM. He also said (if I understood him correctly) this was basic logic of the PCM/TCM based upon time at WOT, vehicle acceleration rate, and load. It will only happen in limited case, such as starting off on a 15% grade with 11K like we were doing.
He gave me a tune to try that will allow the TC to stay unlocked for a longer time in this case. Trade off is TC temp but I think even if the TC stayed unlocked to about 4,000RPM it would have made big difference in performance and still keep the temps in check.

If I could have kept the TC unlocked longer I could have given the newer PSDs (6.0, 6.4) a run for their money and would have beat instead of nearly tied the 7.3 up the first hill. After the first grade the 7.3 couldn't even keep up with my V10 let alone the 6.0 and 6.4. I really would have liked a 3V V10 with a TS tranny to see what it could have done.
No doubt though the 6.0 and 6.4 are smoking fast diesels even in stock configuration. I drove Tom's truck (the white 6.4) and was grinning the whole time up Buffalo Hill. Of course Tom got 4 back to back runs with my truck so I should have taken his truck out 3 more times.