When throttle kickdown is not set at 100%

[joecar]

Graph show what happens when the Throttle Kickdown tables are not set at flat 100%...

( 4-3 Kickdown curve has been axis-swapped to match axes of 3-4 PT Upshift and 4-3 PT Downshift curves )

Above red line = upshift into 4th
Below green line = downshift into 3rd
To right of blue line = throttle kickdown into 3rd

The blue region shows a conflict (PT upshift table wants 4th, throttle kickdown table wants 3rd).

PCM may or may not follow the kickdown table... it won't shift when you think it should, and vice-versa.

[cmitchell17]

I noticed some of my tables were not all 100% so I set them at 100%.

[emarkay]

What about 4-2 kickdowns - that has been my PITA (literally) since 2000!

[joecar]

MRK,

What are you seeing...?

For 4->2 kickdowns the PCM iteratively uses the 4->3 and 3->2 before commanding the downshift.

[emarkay]

OK - that makes sense.

I have been trying to get that kickdown to require MORE throttle input before it happens. Messed with it a year or so but only seemed to confuse thing in the tranny.

As a most typical application instance, a 40 to 60 MPH accelleration at (SOTP) 70% throttle does a 4-2. I'd like to see that changed to a 4-3 and save the 4-2 for 95% WOT -

I know it's possible - I jsut haven't spent the time to play and dig.

[joecar]

The simplest way to adjust what you're saying is to set the kickdown tables to 100% flat and then adjust the PT downshift tables such that at 40-60 mph 70% TP 4->3 is "in the region" and 3->2 is not (i.e. operating point falls below the 4->3 PT downshift curve and above the 3->2 PT downshift curve).

[cmitchell17]

Is this the reason there is a 1-3 second delay on WOT downshifs, or is that a mechanical limitation or something?

[joecar]

I don't know if the delay electronic or mechanical or what...?

The PCM should be able to do it very quick (my stock TA jumps quick-smart, spins tires upto ~35 mph)...

I am wondering if your trans calibration has some delay parameter that has not been discovered/published...?

[FeetDry]

I'm looking for the spreadsheet that has makes the color graph. Is it posted somewhere?

[Lextech]

SSpeedDemon has the spreadsheet you are looking for. (I Think)

Jeff