2014 6l80e Shift transition timing

[czipar27]

Im working with a 14 6l80 and im noticing that the truck is still pulling timing between shifts ( dropping to -15deg.)
i do not want to get rid of all timing removal, for the transmissions sake, but i would like to maybe cut that value in half.
where do i change this?

thanks,
Tyler

[yonson]

Torque Management

[czipar27]

correct, but more specifically what table has control of it? i know you can completely disable it threw the trans torque management but that's not what im trying to accomplish.

[jaydubb71]

Engine>Spark>Advance>Spark Limiters>Spark Minimum - TqMgt

[czipar27]

thank you jaydubb71, I will give that a try!

[czipar27]

worked great! thanks

[jtrosky]

Another way to reduce the amount of timing pulled without modifying the spark minimum table is to reduce the amount of torque management via the Shift Torque Factor Adder and Adder Modifier tables (at least for upshifts). The nice part about these tables is that you can control exactly how much torque management is removed, per shift, per RPM/Toruqe. So, for example, you can remove 40% of the torque management for low-RPM, low-torque shifts, but leave more torque management in place for highe RPM/toruqe shifts.

However, the Shift Torque Facter Adder/Adder Modifier tables only control torque management levels on upshits. The minimum spark table will modifiy the amount of torque management for downshifts as well.

Just some additional options....

[czipar27]

so you just add the amount of timing you would to remove as a positive value and use the multiplayer table to control where it happens?

[mowton]

so you just add the amount of timing you would to remove as a positive value and use the multiplayer table to control where it happens?

Set the specific shift sequence(s) you want to implement TM control by placing a 1.0 in the Shift Torque Factor Adder Table. Using the Adder Modifier, place a 0 in the cells (rpm vs torque) you want full (100%) TM up to a -1.0 for no (0%) TM. There isn't a magic decoder ring that I know o,f but you go by percentage of TM reduction from stock to none. This is reflected in the amount of spark retard applied during the shift. Log the shifts and adjust for feel.

Ed M

[Vettepartz]

jtrosky or mowton - I do not see these tables for an 8-speed 2015 Corvette. Would these be equivalent to the ones in Auto Shift Properties>General>Shift Inertia>Upshift? If so, which way would you go to 'stiffin' the upshift, and about how much to start with?

[jtrosky]

The inertia tables are definitely different from the shift torque factor/factor modifier tables that we're talking about.

My understanding of the Inertia tables (which could be wrong) is that they can be used to modify both the pressures and shift speed via one parameter - but I've always read that you can also accomplish the same thing by modifying pressures and shift speed on their own as well. Typically, with intertia tables, higher values are for "firmer" shifts and lower values are for "softer" shifts. But again, this is completely different than the shift torque factor tables we're talking about.

The tables we're talking about are usually under Trans->Torque Management - but maybe they don't exist for the 8 speed trans yet... If you post the tune, I'd be glad to take a look to see if they are there or not.

[Vettepartz]

Here is the tune:My 2015 01JUN2015.hpt

I am using Version 3.0.120 of the editor.

[jtrosky]

You are correct - I don't see any shift torque factor tables for your car... With the version of 3.0 I'm using, I don't even see the Inertia tables either, but I'm running an older version of 3.0 (I still use 2.24, so I haven't been staying current with 3.0 releases).

So my guess is that you have no "fine" control over the amount of torque management for upshifts like the older 6 speeds do. Not sure if this is something that will be added in the future or not (it's possible that the tables just don't exist in the 8-speeds). You might want to check with HPTuner support to see if they can be added.

[Vettepartz]

Thanks for the reply. As you can see, I have the upshift TM disabled. This makes for a really firm shift, a little more than I would like. If I go back and set it to the enabled mode, the 1-2 shift is pretty mushy and with the exhausts in the 'loud' mode, it sounds like a wailing cat. I am looking for something in between. I think I will enable the TM upshift and then play with the inertia tables.

If anyone else has any ideas, please chime in.