how to adjust transmission shift firmness
11-18-2009, 11:45 PM
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how to adjust transmission shift firmness i have hp tuners the pro version and was wondering if someone could give me some advice on how to adjust how the tranny shifts my 2-3 upshift has a weird delay in the shift and so does the 3-2 downshift if anyone can help me out it would be highly appreciated
thanks
thanks
11-19-2009, 10:34 AM
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Presuming it is in fact a tuning and not a mechanical
issue, the first thing to do is set all your adaptive
shift time targets to 0. This makes the PCM quit
shaving off pressure in seeking "barely meets" times
as a goal, so anything else you do will stay put.
Then you have your (during-)shift pressure and
your modifier tables. Generally increasing the line
commanded here, speeds up the action. But when
you find that it doesn't get faster or firmer with
more, then you can quit adding. You would want
to be logging the input and output shaft speeds
plus converter slip RPM, and the line% and force
motor current, to get observability there.
Your "delay" might have something to do with
torque management. If so then simply shortening
the 2-3 shift cycle (by pressure) might be enough,
or you may want to pull back on its spark retard
authority. Look for timing going to 0 or negative,
during the shift. I prefer to work in the spark retard
vs % torque reduction table, and make it so large
commanded torque cut results in a lesser retard.
Like maybe 10 degress advance during TM instead
of -10.
issue, the first thing to do is set all your adaptive
shift time targets to 0. This makes the PCM quit
shaving off pressure in seeking "barely meets" times
as a goal, so anything else you do will stay put.
Then you have your (during-)shift pressure and
your modifier tables. Generally increasing the line
commanded here, speeds up the action. But when
you find that it doesn't get faster or firmer with
more, then you can quit adding. You would want
to be logging the input and output shaft speeds
plus converter slip RPM, and the line% and force
motor current, to get observability there.
Your "delay" might have something to do with
torque management. If so then simply shortening
the 2-3 shift cycle (by pressure) might be enough,
or you may want to pull back on its spark retard
authority. Look for timing going to 0 or negative,
during the shift. I prefer to work in the spark retard
vs % torque reduction table, and make it so large
commanded torque cut results in a lesser retard.
Like maybe 10 degress advance during TM instead
of -10.
11-20-2009, 04:59 AM
#3
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the tranny worked fine before my swap so im pretty sure it has to do with the tune cause it now has a different computer controlling it so i will have my buddy who tunes my stuff try some of this out and we will see what happens thanks
and if anyone else has some advice i would highly appreciate
thanks
and if anyone else has some advice i would highly appreciate
thanks
11-21-2009, 10:44 AM
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I never found any of that when playing with short
adaptation times, but setting to zero just means
"fuggedaboudit" while setting to 0.01 will make it
try as hard as it can, even though it can't, to hit
that cycle time.
adaptation times, but setting to zero just means
"fuggedaboudit" while setting to 0.01 will make it
try as hard as it can, even though it can't, to hit
that cycle time.
