MSgpio.com read only forums (Jan.15,2018)

Just a suggestion:

I live in an area with many "traffic calming speed bumps". This requires frequent reduction in speed after obtaining Vmax from the previous speed bump. My daughter's S40 Volvo is most frustrating in this area as it only initiates a shift to the correct gear AFTER crossing over the speed bump. My wife's VW DSG based car gets into the right gear BEFORE the speed bump - awesome. I want it the same in my 4L60e implementation - BEFORE the speed bump.

One method of achieving this is to bring the downshift point earlier (at a higher speed than required by the gear map) based on the derivative of the vehicle speed, VssDot. The faster you decelerate (the more negative VssDot), the earlier it downshifts, all tuneable of course. This would also result in the box behaving more sporty the sportier you drive - without map switching.

Philip,

This is an interesting idea. It should be 'doable', but will have to be carefully implemented so that it doesn't screw other things up. I'll try to come up with a plan for this.

Lance.

Philip,

One thing I forgot to mention is that this desired behavior is contrary to the 'decel mode' behavior that is the default for the code. The decel mode prevents downshifts when decelerating.

Decel mode wasn't originally in the code, and isn't something I would ever use, but other users wanted it so that the trans downshifts would be more 'OEM-like'. But decel mode makes the trans much less responsive and less 'sporty'.

So one thing you might do, if you haven't already, is disable decel mode under 'Throttle and Load Factors'. Setting the 'Max. sLoad' to zero (0) disables decel mode completely. There is more on this here: http://www.msgpio.com/manuals/mshift/V5tune.html#gh (you have to scroll down a bit).

Lance.

Thanks Lance

I appreciate the tip

May I point out that this idea of VssDot could possibly tie in very nicely with the suggestion I present this thread: viewtopic.php?f=4&t=1021

A simple VssDot graph could then adjust the downshift speed bin value upwards for the shift bin which is being moved to.