Tuning tool for setting performance shifts

[Red94Chev]

Thought this was cool. Tried it out tonight and I'm impressed with how the transmission shifts now. TCI has a stand-alone controller for electronic transmissions that uses a software interface. The software itself can be downloaded from the TCI website (http://www.tciauto.com/Products/Electronics/default.asp) and is used to set up various electronic transmissions, including GM's 4L60E and 4L80E.

The tuning "tool" is the calibration wizard from the software: http://www.tciauto.com/base/files/PDF/Help/index.htm. Input your setup parameters (tire diameter, rear gear ratio, max shift RPMs, etc.) into the software and you can review the calibrated upshift/downshift vs. TPS% vs MPH table and some other key info. Especially useful if you changed gears, tire size, or performed engine mods that extend the RPM range of the engine (i.e. camshaft swap and/or head swap, etc.), but this would also work for setting performance shifts for a stock or mildly modded engine. Extrapolate the constants/tables to your .bin, burn a new PROM, and go driving. The $0D .bin limits MPH speeds to 125 MPH, so keep this in mind when setting the upper TPS% for the 3-->4 shift. Massive improvement over the CAFE shifts from the factory. There are 16 divisions for the TPS% values compared to 17 in the $0D .bin, so you'll need to fudge the numbers a bit.








Pretty sweet. A word of caution if you want to do this correctly. If you've changed your rear gears and/or tire size, then you'll need to change the RPM/VSS constant so the PCM knows the correct speed of the truck (i.e. through the VSS sensor from the transmission). DRAC settings will also need to be changed, but this is only for the speedometer and has no input into the PCM. Also, if you want higher WOT RPM shifts and your engine supports it, you'll need to match the Normal Kickdown MPH tables (for WOT shifts) to the 100% TPS values of the upshift/downshift table. Fuel cutoff RPM constants will also need to be raised accordingly.

[Red94Chev]

Just an update. I had to tone things down a bit as the settings are good, but I didn't like the 2-->1 downshift during rush hour traffic. Still, very good and precise and it now feels like when you press the gas pedal in that half-way zone, there's an appropriate response from the transmission. Works really well.

[NEUMANNZZ]

[oldred95]

2-1 downshifts at heavy throttle are always a thrill, especially in traffic. If my transmission wasn't busy letting the smoke out of the 3-4 clutch pack I'd give this a try. I'm still going to download it and compare it to what I've got now and see where I could use some improvement.

Does this also have recommendations for TCC settings?

[oldred95]

Just got around to running the program and from what I can tell it does look like the up shifts are very performance oriented, at least at light throttle. I drove around like that for a long time and got tired of having to lift my foot some to get it to shift as it would just hang there at light throttle and didn't want to up shift to the next gear. I do like how they make the down shifts mimick the up shifts, just somewhat lower. My down shift tables are terrible. I think I can barrow some settings from this and mix and match and make something more usable. Again this depends greatly on your engine setup. I lug my engine around town with low shift points because it has the torque to do it. I shift into OD as low as 34mph and have the TCC locked by 36mph at a whopping 1000 rpms at very light throttle and it just moves right alone and with a little throttle increase I'll be doing 45-50 without much trouble when needed and never unlock the converter.

[Red94Chev]

My impression as well. I've tweaked the tables now to my liking and lowered the MPH values in the lower TPS% area under 50% for daily part throttle cruising. The 2-->1 downshift especially needed to be way lower as well as the 3-->4 upshift to get it into O/D sooner for gas mileage. But it's actually fun to play with these tables. There is no way you could produce shift points this easily with a non-electronic transmission.