47rh Modded VB and Tune from Scratch

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
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Joined: Wed Dec 20, 2017 4:17 pm

47rh Modded VB and Tune from Scratch

Post by redrider2911 » Wed Dec 20, 2017 5:10 pm

Hey guys, I just purchased my GPIO board with Transmission Controller pack and have been playing around with Tunerstudio offline. I know there are guys that have attempted to control the Chrysler transmissions with the Electronic Governor Pressure Solenoid, with very little success. I plan to mod my valve body so that it acts more like a 4L60E. 4th gear and TCC lockup already have a solenoid dump valve to control them, I plan on adding a solenoid dump valve to control the 1-2 shift valve and another one to control the 2-3 shift valve as well. I will feed these passages with line pressure to push the shift valves over on-demand. I then plan on modifying the throttle valve and pressure valve circuits so that a Pressure Control Solenoid solely controls line pressure.

My question comes in with tuning and a few different strategies I would like to implement; mainly for TCC lockup control. This being on a Cummins diesel daily driver, tow rig, and weekend drag race truck; may leave me with some overzealous goals...

I was thinking of using the TCC as like an in-between gear on every gear. I think this would be pretty simple... I could put it on Output 4 and then use it in the Shift Output Patterns section to indicate that the transmission has 8 gears...

Gear; Output 1, Output 2, Output 3, Output 4
1st; off, off, off,off
2nd; off, off, off, on
3rd; on, off, off, off
4th; on, off, off, on
5th; on, on, off, off
6th; on, on, off, on
7th; on, on, on, off
8th; on, on, on, on

The main problem that I see with this is that I would not be able to implement the TCC unlock on upshift or downshift feature nor the "selective clutch" feature, correct?

I also want to be able to flip a switch in the cab to go to "race mode" where it would lock the TCC in the bottom of 2nd and stay locked throughout all the shifts. It appears that there is a "TCC Full-Time" mode that I could use for this? But is there a way to easily turn it off and on with a switch?? What about using the switch in place of the 4 low option to change between the "auto shift table 1" and "auto shift table 2".

My last goal/problem is I want to be able to "slide" the shift points over on the table whenever the brake is applied. This would be great for downshifting logic when engine braking and towing a trailer.... I did just have an idea of maybe wiring up the brake switch to trigger the RPM input somehow since I don't plan on using that?? Any reason I couldn't or shouldn't use that to send a high signal to that input, and then have a straight cutoff table between "max RPM' and "minimum rpm" that would raise the TPS signal a few points?

Anyways, sorry about the long thought process; just hoping some guys who are more experienced than me with TunerStudio might have some good ideas.
Thank you for your time,

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