TCU Tuning Smart 451 G2T601 (MH8102F)

[ExpatMat]

I'm about to attempt modifying the shift speeds on my Smart 451 TCU, any advise will be welcome.

The shift speed maps are a matrix of RMP vs Throttle position with shift time in each cell, repeated for each gear pair (1-2, 2-3, etc).
My initial thoughts would be a percentage reduction across the 1500-4000 rev range (I'm sure this is not the best way, but I need to start somewhere).
One problem my locations for testing are limited in my locality, so again advise would be appreciated.
I'm planning on trying to do some data logging when I get time and a logging setup that works (all new to me).

I have a customized XDF file with only Shift time maps, which I would be happy to share with members who are willing to use the XDF and share their results.
The XDF file is work in progress and is currently protected against changes. Note checksum correction is not done within the XDF.

Map locations change depending on P/n and or Firmware. If anyone needs a copy of the XDF, send a dump of the TCU along with P/n a FW number. I will make sure that the XDF matches the dump.

One last question for now:
The TCU variant coding has a 'Map Switching' option (On/Off) can anyone explain what effect this has? (Please don't just say 'it switches the map).

Thanks & regards.

 

[ExpatMat]

Update:

After a few attempts using various percentage modifiers, I've settled on my penultimate (maybe final) reductions.
I initially used a fixed percentage across all throttle positions, but on a couple of (3) occasions the gearbox would drop out of sync and show 3 bars.
This only occurred in automatic mode when changing down at low RPM/Throttle.

The final ratios I used are:
20% reduction RPM 999+ with throttle position below 25%.
34% reduction RPM 999+ with throttle position above 25%.

I've been running with this map for a couple of months with zero dropouts.
Will I try to mod the map further? I'm not sure.
Maybe I will look at road speed vs up/down shifts, as I feel the car shifts up too early in auto mode.
I also need to record the CAN bus to try to determine which shift/speed maps are being used, when and why.

My driving style is relaxed and I don't regularly push the TCU to the limits, but occasional aggressive TCU shifts have performed well without problems.
I have used Tunerpro to perform the changes (bought the definition file from Oldskulltuning).
TCU read/written using KT200II, (checksum correction performed when writing).

The car? It's a 2008 451 Turbo with a stage 1 remap.

Hope this helps someone in a similar position.

I have since used the same parameters to remap a friends 451 MHD TCU without problems (so far).

Regards.