2018+ OSS map

[aaronson]

Currently working on a 2020 gt A10. One thing I noticed is the stock OSS speed(@WOT) is 1700 rpm and the engine rpm that it shifts at is 7500rpm. Assuming 1=engine rpm and the first gear ratio is 4.70, then technically speaking it should shift at 7990rpm. But I?m assuming since the torque converter isn?t locked the engine rpm /= 1. Which means there?s a 6.33% slip between the engine input and the transmission output for first. Regardless of that, if you divide 7500/1700 you get roughly 4.41 as the ?first gear ratio? so say if I wanted it to shift at 8000, I would do 8000/4.41 and get an OSS rpm of 1814 rpm. Is this a correct assumption? I?ve been fortunate enough to only have to do manual 18+ up till this point.

[rryanfla]

This thread may help. This guy did a spread sheet for the 6R80 too and it worked like a champ.

https://forum.hptuners.com/showthrea...ight=Oss+excel

[aaronson]

This thread may help. This guy did a spread sheet for the 6R80 too and it worked like a champ.

https://forum.hptuners.com/showthrea...ight=Oss+excel

It works perfectly, the issue lies in Ford values. The OSS speed and stock rpm speed don?t calculate out to the gear ratios so you have to fudge it a bit I managed to work it out it?s just weird

[LastPlace]

1	2	3	4	5	6	7	8	9	10	r
4.69 : 1	2.98 : 1	2.14 : 1	1.76 : 1	1.52 : 1	1.27 : 1	1.00 : 1	0.85 : 1	0.68 : 1	0.63 : 1	4.86 : 1

Ratio

4.6957

- 2.9851

- 2.1462

- 1.7690 -

1.5201 -

1.2700 -

1.0000 -

0.8536 -

0.6892 -

0.6357

- 4.8661

[LastPlace]

Don't over complicate it...

[aaronson]

Don't over complicate it...

I completely understand, what I was saying for example you want your 1-2 shift at 7800rpm you do 7800/4.69 and that gives an OSS rpm of 1663 roughly. The problem is the bone stock ford data OSS map for the 1-2 shift is already 1700 rpm. Yet shifts at 7300 rpm engine speed. So it?s not a straight across division and you have to fudge it a bit to make it work. I?m not sure if it?s a translation issue or just ford in general. None the less I got it to shift properly using my thought process and I?d be happy to help anybody that?s having similar issues.

[engineermike]

There’s a separate wot shift table that is in engine rpm. It might use the lower of the two values. If that’s the case, then the wot shift map could be set at 7300 and the oss shift map just moved up out of the way.

[OzTuning]

There’s a separate wot shift table that is in engine rpm. It might use the lower of the two values. If that’s the case, then the wot shift map could be set at 7300 and the oss shift map just moved up out of the way.

It is exactly this. 6R80 and 10R80 both use this logic, but shifting will be more accurate if you make the WOT RPM values and Shift Schedule values match.