Normal mode skip shift elimination-PCMtec

[K4fxd]

Interpolate? Not sure how that's done.

You take two points in the table column and have the software blend them together so it is a smooth transition.

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[Robottrainer]

That's a good start. I almost always past this table into excel to graph and problem areas jump out at you when you use a line chart. I don't mean to pick nits, but the circled areas will cause some minor issues. The red ones trigger a shift to a gear that it will immediately shift out of, so in effect it will still skip-shift. You could lower them but then the spacing between shifts will be wonky (2-3 and 3-4 only 50 rpm apart). Again, plotting them in excel makes these issues easier to see and edit. The yellow part shows a decrease in shift rpm as pedal increases, so it should be changed to make it a constant increase.

Some time back I resolved a bizarre issue with the Roush F150 OS where the downshift 100% pedal row, and only that row, was somehow affecting/corrupting the entire associated column. That took me forever to figure out. I was able to resolve it by simply putting 0's in the 100% row and then suddenly the table worked fine. My buddy, who is a hex wiz, figures there's some sort of table call address error in the logic. PCMTec suggested I let Roush know, which I declined. Can you imagine how that phone call would have gone?

They will ignore you

 

[Robottrainer]

They will ignore you

Roush does some strange stuff. And they deny they touch the trans schedule(s). And seeing what you point out leaves one to scatch their heads as to why the non linear rpm.

 

[K4fxd]

And seeing what you point out leaves one to scatch their heads as to why the non linear rpm.

Look at several Ford auto trans tunes. All have that quirk.

Here is a stock gen2

 

[shogun32]

My buddy, who is a hex wiz, figures there's some sort of table call address error in the logic.

" I must have put a decimal point in the wrong place or something. I always do that. I always mess up some mundane detail."

 

[Robottrainer]

" I must have put a decimal point in the wrong place or something. I always do that. I always mess up some mundane detail."

That's why things bounce off the atmosphere.

 

[Jjmoberg]

No idea what he did or how he did it, but my tuner used PCMtec to dial in my transmission shifting in all modes perfectly as far as im concerned. Also eliminated the stupid 1-3 skip shift. Took a few tries at his end but I love it now.

 

[Robottrainer]

Attached is the original normal mode upshift schedule, original and modified. Opinions... On the fence as to whether I want to muck with this or leave sleeping dogs lay. This is more of a learning how this works exercise for me. I do this for a living with robots and automation. Automotive dynamics isn't the same beast. But like robot, there are thousands of parameters you leave along because they dont make things better if you play with them and often times makes things worse, but its very interesting how this all works.

 

[K4fxd]

You have a couple of big jumps but that should work just fine. Save a copy of the stock table so if you don't like it you can put it back.

 

[Robottrainer]

You have a couple of big jumps but that should work just fine. Save a copy of the stock table so if you don't like it you can put it back.

I did it manually. I tried the smooth the column function but the numbers seemed high. Now to figure out where the torque management tables are for alt 1 and two and compare them to normal mode for the 3 4 and 4 5 shift. See if I understand what is going on in there

 

[Robottrainer]

The

I did it manually. I tried the smooth the column function but the numbers seemed high. Now to figure out where the torque management tables are for alt 1 and two and compare them to normal mode for the 3 4 and 4 5 shift. See if I understand what is going on in there

Rpm is os rpm and not engine rpm?

 

[K4fxd]

Rpm is os rpm and not engine rpm?

yes

 

[engineermike]

@Robottrainer looks like an ok first pass. Just keep in mind that even after I’ve been doing this for years I never expect anything to work right on my first try. With pcmtec, a reflash is just 30 seconds away, and I’ve been know to pull over on side of the road for a reflash. Don’t sweat trying to get it perfect on the first try because it usually won’t happen.

I was trying to get my Roush truck torque response, shift points, tcc lock points, and shift firmness just a certain way. It’s actually pretty hard to get all those interacting right together if you’re picky. I think it took a 20++ iterations but when I finally got it, it’s totally worth it.

 

[engineermike]

The

Rpm is os rpm and not engine rpm?

That table is trans oss, or driveshaft rpm. There is another wot shift point table that is in engine rpm and it picks the lower of the two to trigger the shift.

There is another table if you want to set up roll-race/dyno mode and it’s in oss as well. This forces a shift up even if you’re in sport-paddle (sst) mode. On a side note, I’ve also set mine up to prevent downshifts if you’re in drive-paddle (LID) and hold the mode for 30 seconds instead of the stock 2 seconds. This prevents unwanted downshifts if I paddle down to downshift.

 

[Autopart101]

@Autopart101 looks like an ok first pass. Just keep in mind that even after I’ve been doing this for years I never expect anything to work right on my first try. With pcmtec, a reflash is just 30 seconds away, and I’ve been know to pull over on side of the road for a reflash. Don’t sweat trying to get it perfect on the first try because it usually won’t happen.

I was trying to get my Roush truck torque response, shift points, tcc lock points, and shift firmness just a certain way. It’s actually pretty hard to get all those interacting right together if you’re picky. I think it took a 20++ iterations but when I finally got it, it’s totally worth it.

Not for me....

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