Bob wrote:
>I haven't seen the issue yet but, by coincidence, I went to the track today
>to test the capability of the '97 MP PCM auto. (CA version ... no Fed
>version).
>I did two runs with it and recorded both on the scanner.
>
>First run: 15.854 @ 89.06 with manual 1-2 shift at 4800 and 2-3 shift at
>5100.
>Second run: 15.5523 @ 89.38 with both shifts at 5200.
>On both runs, the tranny behaviour can best be described as begin the
shift,
>wait a second, do I really want to shift, and then, hell, complete the
shift.
>
>I have not gone over the recorded PCM outputs in detail but a limited look
>indicated that timing across the rpm range was below that of the '96 MP PCM
>and that there was a dramatic timing retard just at the 1-2 shift ... my
son
>anticipating
>a pinging situation.
>
>On the third run, I put in the '96 MP PCM, shifted as in the second run
>and got a 14.908 @ 92.09 (this was with a small lift-off on the 1-2 shift
>to get the tranny to shift and TWO small lift-offs on the 2-3 shift to get
>the shift to complete ... if any of you have seen the movie, Bullit, you'll
>know how this sounds.).
>
>Bob. Ont, Canada.
>'97 Dakota CC, 5.2L, 4x2, 3.92 SG, auto., 4265 lb.
>PB: 14.737 @ 91.75 9.364 @ 72.95
In the article on the Y2K Dakota R/T, they mention "We also learned during
our first run that manually shifting the 46RE four-speed automatic trans any
later than 5,000 rpm would allow the 5.9L Magnum V-8 to hit the rev limiter
before the 5,200-rpm redline shift completed itself."
That's a mouthful, and I haven't quite figured out what they're saying
yet.... may relate to what you found.
Also, in the article on the '97 SLT, they mentioned that they installed the
computer and drove the truck for a week so it could "learn" the driving
style (ala Adaptive Memory), then made their dyno runs and switched back to
the factory computer to finish the dyno runs. Either way, it seems kinda
hard to compare the computers on dyno runs or at the track if they have to
"learn" new driving styles.....
btw, I know what you're talking about on the "Bullitt" movie (greatest chase
scene ever filmed!) - sounded like McQueen was double-clutching that
'stang......
-- '92 Dak CC 2wd 318 3.55 '84 GoldWing Interstate
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