Just received a new tune and noticed during wot shifts spark advance basically drops down close to zero during the shift. I've never seen this on any other logs. Anyone know the reasoning for this? Is this normal behavior?

 

In the tune there's torque management. It will pull whatever throttle and spark required (on the ecoboost also boost) in order to make the shift smoothly. All torque management is made to smoothly perform shifts. If it's cutting timing during shift it means it's a compromise shift if it's for "performance". It means there's still SOME torque management there.

 

I briefly covered this in my tune comparison thread. It'll be slower, but it will also help the transmission last longer.

 

I'll find it and look through it. That's interesting though because this is I have 2 tunes from this tuner and this is the one that is more performance oriented. The other daily/tow tune does not behave like this during shifts. This is the very first version of each tune. There will definitely be some data logging and revisions to do.

 

I looked over your post so with this tune there is 0 knock through the entire pull, positive or negative but still during the shifts spark dips from 28ish to almost zero(non nitrous tune). My tune with MPT has spark stay static during shifts, and actually usually adds 4-5 degrees of timing through the knock sensors. Does this show that this new tune has the knock sensors turned off? Or at least won't allow to add additional timing in?

 

Oem shift strategy pulls timing through the shifts for various reasons, including shift smoothness and wear and tear on drivline parts. Even manual transmissions in the Mustang do this during shifts.
Performance tunes usually turn this off as it is faster.....though wear and tear are higher. Ask my 3rd and 4th gear clutches.

 

Manual transmission mustangs pull timing for "anti shuffle". It cuts timing on shift and slowly adds it back in as you rev out, generally way too slowly lol.

 

Thanks for the info gents. I do have a better understanding now.

 

Can you please elaborate on the reason for this with the manual trans? I'm not sure what "anti shuffle" is, Thanks

 

They don't want you to slam 1st to 2nd and spin out into a wall when you get back into the throttle. Shuffle, is just what they're calling movement on shift from tire spin.