Normal mode skip shift elimination-PCMtec

[Robottrainer]

Gotta be careful generalizing about the shift torques because it varies by gear, input torque and rpm. For instance, for the 4-5, alt 1 has the very lowest shift torque of all at both part and full throttle. Alt 2 has similar shift torque to base/normal except at high torque and rpm, where it doesn't reduce it at all.

@Robottrainer, there is some physical difference causing the flare, like a sticking solenoid or excess clutch clearance. Who knows, but the stock shift characteristics work well with no flare on the vast majority of supercharged cars and trucks. I would call it a "win" because you were able to address your issue with a simple tuning change to account for the physical difference.

That said, I don't claim to have an intimate understanding of the shift logic. I even started a thread to discuss and I don't think many out there really understand the logic and mechanism. Take this FWIW....

I believe some of the parameters are deltas. For instance, there is no inertia phase duration multiplier for base because the multipliers are assumed to be 1.0 for base. Alt2 uses multipliers down to 0.2, as an example.

In the following comparison of base, alt1, and alt2, you can see that base offgoing ramp delta times are largely positive numbers in the higher torque areas. I tend to think this might have something to do with your flare issue.

While I'm no expert on trans tuning, I feel pretty comfortable making changes to the torque modulation tables. If you wanted to test your theory about shift torque and alt1, you could always zero out the alt1 shift torque modulation table and see if that makes it better or worse.

This is more of an inquiring minds thing. The tables you show are HP tables. I think PMCtec calls them something else.

I think you are correct about variations in mechanical tolerances. The trans tech I talked to says the clearances in clutches are all over the place. The software isbone size fits all.

The Ratio Tek shift kit has an interesting mention about testing solenoids using a scale and applying 6 volts to it. Apparently the amperage is variable. Amps would control the speed of the solenoid force (P=V x I). So again, another variable.

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[Robottrainer]

I populate all the upshifts between load and rpm plus the rpm drop per gear ratio to have the smoothest linear acceleration. Takes time but to me it's worth it. Also make sure to properly calibrate the downshift and coastdown tables as well. I have the car always in the right gear coming out of a turn at any speed, it never has to hunt or clunk it's always ready to smoothly accelerate away.

I suppose if one were happy with the sport up shift schedule they could copy the upshift and coast values into the normal tables

 

[engineermike]

Yes but don’t forget the downshift tables. There are some other shift ancillary tables that may need to be copied as well.

 

[K4fxd]

Yes but don’t forget the downshift tables. There are some other shift ancillary tables that may need to be copied as well.

I tried, using HP tuners, copying the torque converter settings from sport to base and it did not work.

Someday I'll try again using PCMtec

 

[Robottrainer]

Yes but don’t forget the downshift tables. There are some other shift ancillary tables that may need to be copied as well.

Yes. I think there is a cold table too

 

[engineermike]

I tried, using HP tuners, copying the torque converter settings from sport to base and it did not work.

Someday I'll try again using PCMtec

The torque converter is weird. I’ve fought with tuning it a lot. Some things I figured out and some I never did.

 

[Robottrainer]

Alt 2 is definitely working for me in Sport/track. The only issue is it's a tick too harsh 2 to 3 at 2000 to 3000 rpm area so I might try toning down the torque values in the Alt 2 tables maybe a little above the Normal table as it works but is a bit too soft. Somewhere in between is the ticket.

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