Help Tuning 6.2L 6L80E Its retarding timing 0 knock

[400ss]

Im still learning, thats why i need help.

I did an engine swap on a 2005 Jeep JK , i installed a 6.2L with a 6L80E..

Engine is working fine and transmission too..

But in WOT the timing stays betwen 2-17 degrees and even negative numbers, but it isnt nocking, i modify some tables to check if it was retarding timing but i havent had any luck, can someone take alook on the tune and the log and help me please

The stock tunes from the files i atached are on tunefiledepot

[400ss]

The Knock sensor on Bank1 wasnt connected, i did connect it, and modify some tables on the tune and the spark timing looks to be working fine.. can someone take a look on the current tunes on the car and see what i can changue or how i can improve it,, im still learning and i dont want to mess with the VE tables, so i probably will convert it to MAF only tune and tune the MAF with a WIDEBAND, thanks everyone

[joecar]

I can take a look at your files over the next few days...

[joecar]

After a quick look:

trans file:
- part throttle shift tables: curves cross each other;
- TCC apply/release tables: curves cross each other;

when the curves cross each other, it becomes unpredictable which gear will be selected at the current operating point...

for example, if the 5->4 curve dives underneath the 3->4 curve, what gear should be selected as the operating point passes this crossover...?

[400ss]

Thats why when i in WOT car will not downshift or upshift it only revss to 5000-6000 and i need to remove my foot from the pedal

thanks you alot

but i really havent understand about part throttle shifts and downshifts
i mean how to setup part throttle shifts and tcc, car has 4.56 gears a 35inch tires,

After a quick look:

trans file:
- part throttle shift tables: curves cross each other;
- TCC apply/release tables: curves cross each other;

when the curves cross each other, it becomes unpredictable which gear will be selected at the current operating point...

for example, if the 5->4 curve dives underneath the 3->4 curve, what gear should be selected as the operating point passes this crossover...?

[joecar]

That's the other thing also, the WOT MPH and WOT RPM shift points have to be analyzed for consistency with each other and the PT tables (need tire diameter in inches, and axle gear ratio)...

for a WOT shift, both the WOT MPH and WOT RPM have to be met (exceeded);

you also have to check that WOT is being triggered (compare D1251, D1250 with SAE.TP and GM.ETCTP).

[400ss]

Does WOT shifts only use the WOT MPH and WOT RPM parameters?? because on part throttle shift on the tables it has from 0% TPS to 100% TPS

And i ask this because in 4Low it will shift from 1 to 2 then to 3 but it will not shift to 4-5-6

(i have to clarify that this engine/trans is on a 05 TJ Jeep, is a 2wd Tune , but i think it should shift even in 4Low because the 6L80E has the VSS inside it


That's the other thing also, the WOT MPH and WOT RPM shift points have to be analyzed for consistency with each other and the PT tables (need tire diameter in inches, and axle gear ratio)...

for a WOT shift, both the WOT MPH and WOT RPM have to be met (exceeded);

you also have to check that WOT is being triggered (compare D1251, D1250 with SAE.TP and GM.ETCTP).

[joecar]

WOT shifts use only WOT MPH and WOT RPM parameters (for a paricular WOT upshift, both parameters must be met before the TCM commands the upshift)...

when switching from Part Throttle to WOT, you want the PT tables MPH tables to agree with the WOT MPH parameters to avoid any surprises.

I'll have to take a closer look at your tables...

yes, if the TCM is able to understand that the transfer case is in 4LOW mode then it should be able to use the 4Low tables.

[400ss]

On a 2WD 6L80 the TCM and ECM uses the speed sensors inside the 6L80,, on 4x4 6L80 trucks, it has a VSS on the transfer Case, this vss goes to the E38 ECM,
on the car im working it does not have the VSS on the transfer case, it is using the internal speed sensor of the 6L80E, so the PCM and TCM doesnt know that im on 4Low so as long as it hits the MPH and RPM it should shift right?? when i switch to 4Low, it will hit limiter and shift to 2nd hit speed limiter and shift to 3rd then will hit limiter and will not shift even if it is reaching the mph and rpm, i dont know what is going.. it shifts all 6 gears in part throttle on 4Low..

If you need a specific LOG i can provide it, i want this to work as it should.
i atached the latest tunes on the car
I modified the trans tune, pressure and shift times


WOT shifts use only WOT MPH and WOT RPM parameters (for a paricular WOT upshift, both parameters must be met before the TCM commands the upshift)...

when switching from Part Throttle to WOT, you want the PT tables MPH tables to agree with the WOT MPH parameters to avoid any surprises.

I'll have to take a closer look at your tables...

yes, if the TCM is able to understand that the transfer case is in 4LOW mode then it should be able to use the 4Low tables.

[joecar]

Hmmm... I forgot about VSS coming from the transfer case... when in 4 Low which tables does the TCM use...?

[joecar]

...
but i really havent understand about part throttle shifts and downshifts
i mean how to setup part throttle shifts and tcc, car has 4.56 gears a 35inch tires,PT shift table relationships:

basic relationships:
1->2 curve should be above 2->1 curve;
2->3 curve should be above 3->2 curve;
3->4 curve should be above 4->3 curve;
4->5 curve should be above 5->4 curve;
5->6 curve should be above 6->5 curve;

additional relationships:
3->2 curve should be above 1->2 curve;
4->3 curve should be above 2->3 curve;
5->4 curve should be above 3->4 curve;
6->5 curve should be above 4->5 curve;

this can be summarized as: the curves cannot cross anywhere;

if they cross anywhere, then you will not be able to predict what gear the TCM selects when the operating point hits the cross.

[joecar]

On a 2WD 6L80 the TCM and ECM uses the speed sensors inside the 6L80,, on 4x4 6L80 trucks, it has a VSS on the transfer Case, this vss goes to the E38 ECM,
on the car im working it does not have the VSS on the transfer case, it is using the internal speed sensor of the 6L80E, so the PCM and TCM doesnt know that im on 4Low so as long as it hits the MPH and RPM it should shift right?? when i switch to 4Low, it will hit limiter and shift to 2nd hit speed limiter and shift to 3rd then will hit limiter and will not shift even if it is reaching the mph and rpm, i dont know what is going.. it shifts all 6 gears in part throttle on 4Low..

If you need a specific LOG i can provide it, i want this to work as it should.
i atached the latest tunes on the car
I modified the trans tune, pressure and shift timesIf it hits the RPM limiter, this indicates that the either of the WOT RPM and/or WOT MPH parameters are not being met...

reduce the WOT RPM parameter, and use the following formula to calculate the shift RPM from the WOT MPH parameter and see if it is going to hit the RPM limiter:

rpm = mph * 336 * gear_rato / tire_diameter

where:
tire_diameter is in inches;
gear_ratio = transmission gear ratio * transfer case ratio * axle ratio;

typically you can make either of WOT MPH or WOT MPH much lower than required to ensure that it is met (i.e. using the other parameter to trigger the shift).

[joecar]

With D1251 set to 98%, you might not even be going into WOT mode, so you would be using the 100% column of the PT tables.

[joecar]

I need to go read up how the transfer case influences the TCM in selecting the shift pattern and VSS...

[400ss]

Thank you alot, i been reading and i been larning, really apreciate it, i been reading alot about A6 transmissions.

I found this interesting info::

The 6L80E has very complex shift logic. For the most part it uses two qualifiers, MPH and RPM. The problem is, the tranny is smarter than us. It actually calculates the acceleration through the gear and seems to make adjustments for the next shift. Take the 1-2 shift for example. We spend so little time here the car actually uses MPH to calculate desired shift point. This is very evident in stock form regardless of RPM setting. The remaining gears with stock power actually have an opportunity to use the RPM qualifier. The RPM qualifier becomes more evident as the stall of the converter is increased. This is because TCC slip is calculated/used in just about every mode of the transmission. The TCM sees this slip and seems to bias the shift towards RPM. Add in more HP and the TCM has to make these calculations quicker.

Wheel spin is the biggest killer to any desired shift point. A vehicle which is spinning through the gears tends to confuse the TCM as it references tire rotation. If you are having trouble with your 1-2 shift, look for wheel spin. Try setting all RPM values to 100 and adjust your shift points based on MPH

[400ss]

im not using the VSS in the transfercase,, so when i go into 4Low ECM and TCM does not know that im on 4Low, im always on the normal patern, so it should shift, as you say it only needs to hit the RPM and MPH qualifiers


I need to go read up how the transfer case influences the TCM in selecting the shift pattern and VSS...

[400ss]

how muh % do you recomend me?? 80 to triger and 87 to go out of WOT?


With D1251 set to 98%, you might not even be going into WOT mode, so you would be using the 100% column of the PT tables.

[joecar]

how muh % do you recomend me?? 80 to triger and 87 to go out of WOT?
The disable has to be less than the enable...

Try 90% to enable, and 85% to disable.

[joecar]

im not using the VSS in the transfercase,, so when i go into 4Low ECM and TCM does not know that im on 4Low, im always on the normal patern, so it should shift, as you say it only needs to hit the RPM and MPH qualifiersAh, I see now, even though you select 4Low, the TCM does not know... so it keeps using the normal pattern... where does the TCM receive a VSS value from...?

[400ss]

From the internal speed sensor the 6L80E has,, internal vss sends to TCM, TCM sends the speed to the ECM using OSS wire.


Ah, I see now, even though you select 4Low, the TCM does not know... so it keeps using the normal pattern... where does the TCM receive a VSS value from...?

[joecar]

From the internal speed sensor the 6L80E has,, internal vss sends to TCM, TCM sends the speed to the ECM using OSS wire.Ok...

so this means the TCM believes VSS to be based on internal gear ratio and axle ratio, and does not know about transfer case ratio... what is the transfer case ratio (in 4LOW)...?

The transfer case ratio would make the engine RPM be higher for the same MPH... or the MPH be lower for the same RPM... so this means the WOT MPH parameter is not being met.

[400ss]

Gear Ratio for the NP231 is 2.72:1

ok so thats the problem. but if a changue the MPH to work on 4Low it wont work without 4Low right??

What happen if i set all the WOT shift speeds to 10 mph and set the desired rpms?



Ok...

so this means the TCM believes VSS to be based on internal gear ratio and axle ratio, and does not know about transfer case ratio... what is the transfer case ratio (in 4LOW)...?

The transfer case ratio would make the engine RPM be higher for the same MPH... or the MPH be lower for the same RPM... so this means the WOT MPH parameter is not being met.

[joecar]

Gear Ratio for the NP231 is 2.72:1

ok so thats the problem. but if a changue the MPH to work on 4Low it wont work without 4Low right??

What happen if i set all the WOT shift speeds to 10 mph and set the desired rpms?If you make the MPH low and set the RPM to shift, this is good.