Well, I made some changes to the shift times, shift torque factor, X Y & Z base shift pressures and disabled discrete shift torque with all TM options enabled.
My truck is shifting great! Quick and easy during light throttle and nice and firm at WOT. It will spin the front tires from a stand at launch (not an easy task for AWD) and chirp the belts on the 2-3 and 3-4.
2019 F-150 3.5 EcoBoost 4x4
Hey Kenny C,
You mention you've disabled Discrete Shift Torque. Do you know exactly what this is and do you believe disabling this is making a positive difference to the 2-3 shift. I noticed that the Discrete Shift Torque is only enabled on the 1-2 and the 2-3 shifts.
Discrete Shift Torque....I have no idea what it is.
I can tell you my G8 shifts much better with it disabled; I disabled it after looking at a few other tunes that had it turned off.
I had a suspicion that it was a 2-3 flare up contributor....and I was going to suggest try it disabled, but looks like he did.
2017 Chevrolet SS, Orange Blast Metallic, Rotofab CAI. Headers coming soon. Stock Tune for now
Previous Rides: 2008 G8 GT, 2004 GTO, 2004 GTP, 2002 TA
I'm almost convinced it's a 2-3 flare contributor too. I've recently (in the last 2 hours) turned mine off and I'll see what happens.
In the Adaptive shift section, do you know what the Max Adapt Volume is for and why they have set every shift at 200 but left the 2-3 shift at 40? I've also bumped that up thinking it's the Max adaptive pressure the TCM will produce if a shift is going bad (in other words to compensate for a flare or similar). I've bumped it upto 200 like the rest but haven't taken the beast for a spin yet.
Thanks for that. I've read that so many times and every time I read it again it makes a little more sense. I've removed it and I'm going to assess how this affects the changes. It's only enabled on the 1-2 and 2-3 changes which happens to be the only changes which people seem to have issues with mainly.
I've also increase the Oncoming Volume Preset. I noticed it was set to one of thelowest figures (21.500). I've bumped it up on the 2-3 change to 40.000 and I'll see how that affects the shift too.
Can someone confirm with me..... When changing the Base Shift Pressure Upshift tables; are you making changes to the Main pressure or the individual shift soleniods as mentioned in post #23 of this thread.
Well here is a summary of my testing for all you guys out there with the A6:
My personal issue (symptom) was a constant flare on the 2-3 shift. This would occur after driving for about 5 minutes from cold start and would continue for ever and a day. Note, this is separate to all the guys out there complaining of a 2-3 shift flare on the first 2-3 change from cold. In other words, my particular transmission appeared to have an issue with the low pressures.
I have continued to tackle the issue by bumping up the "Base Shift Pressure Upshift" tables for the 2-3 shift. This method has brought significant positive results and I was able to almost elliminate the flare. However the transmission was constantly running significantly higher pressures on that shift but nothing too extreme compared to the other shift tables.
I have recently noticed that the "Max Adapt Volume" for the 2-3 shift was set significantly lower than the other shifts (set at 40 while all other shifts are set at 200). After receiving some assistance from other forum users, it appears this table relates to the MAXIMUM volume of fluid the transmission uses in the "Adaptive Pressure" scenario.
Using this theory, I have increased the 2-3 shift "Max Adapt Volume" to 200 in order for it to reflect the same reading as the other shifts. I have returned the "Base Shift Pressure Upshift" tables to stock pressure levels on the 2-3 shift. Note, all other times while running the stock pressures the transmission constantly flares on the 2-3 shift no matter what temperature the transmission is running at.
After about ten (10) minutes of driving I have noticed the 2-3 shift is clean, crisp yet smooth. AND VERY CONSISTENT NO MATTER WHAT THROTTLE % I'M USING. I am absolutely amazed at how the transmission appears to have adapted to achieve the desired shift time and feel. The transmission has literally never felt that nice on a 2-3 shift EVER!!
In summary, I would use the theory that my particular transmission was NOT able to achieve the desired shift (no flare) while the "Base Shift Pressure Upshift" tables were set so low from the factory and was also unable to compensate enough through the Adaptive Pressure shifting as the "Max Adapt Volume" was set so low also. When increasing the amount of fluid the transmission has available to use through the "Max Adapt Volume" table, it would appear the transmission all of a sudden has enough fluid to achieve the desired shift time and feel.
I'm very excited by what I have been able to achieve in my particular scenario and I hope that some of you out there with a flarey A6 on the 2-3 shift can also acheive great results. I am, of course, open to comment both positive and negative. I don't believe that I'm asking too much of the transmission by increasing the "Max Adapt Volume" to 200 as every other shift is set to that level. But like I've said before, I'm no eggs spirt and am open to feed back.
Look forward to it!!
P.S. Just out of interest, I had disabled my "Discrete Shift Torque" but have returned it to stock (enabled on the 1-2 and 2-3 shifts) after increasing the "Max Adapt Volume" table. I have not found that the "Discrete Shift Torque" is contributing to any flare.
I used the config file that I attached when tuning.
Good pickup Bluessv about the max volume only being 40. I've never noticed that before. I guess most trannys only require that but yours needs a bit more.
When changing the base shift pressure, it only changes the base pressure. This is PCS 1 Commanded pressure when you log. This pressure is delivered to the clutch pressure control solenoids (PCS). The clutch PCS then regulates this to give the required pressure to it's clutch during a shift. The oncoming pressure preset and offgoing pressure preset tables do affect the pressure for the individual clutch PCSs but I'm not sure how they work.
Last edited by carneb; 02-18-2009 at 02:03 AM.
VE Calais V 6.0L L98 V8 6L80E
Possibly the reason for the different adapt volume for 2>3 is the clutch combination used. The 2>3 requires 2-6 to be released,and 3-5/Rev to be engaged. 3-5/Rev appears to have a smaller clutch volume.
But if it works raising to 200, why not!
Thanks Carneb about the info on the "Oncoming Pressure Preset" tables. I had a strong suspicion those tables were the ones to look at but I'm in your boat cause I've got no idea about how they work and what their limits might be.
Perhaps this is something that Bill or Chris from HP could jump in on?? However in saying that, it appears my trans is working correctly for the first time in it's whole life.
I've spoken to a few guys over here in Australia who have stripped down these trans. They have made mention that some are coming out of the factory with clearances bigger than what they should. As a result, the tune and pressures work fine in normal situations but if you're unlucky enough to get a trans with bigger clearances (like me) then the pressures set in the tune are just not enough. This theory certainly fits with the symptoms displayed by my trans anyway. Don't know if that explanation has ever surfaced in the US??
I think the adapt volume is only for the oncoming clutch so it doesn't matter which clutch is offgoing. If this is the case then the volume adapt for 2-3, 4-5, and N-R should all be the same because the 3,5,R clutch is applied for all these shifts.
I'm not so sure that the theory about excessive clearance is correct. Before a shift occurs the TCM fills the oncoming clutch with fluid so that all the internal clearances are taken up, and as soon as it is ready, the clutch can take the torque load away from the offgoing clutch. The TCM needs to know the fill volume so it knows exactly when the oncoming clutch is ready to handle the torque. If it fills too early you get tie up between the clutches. If it fills too late you get flare. The TCM can detect this and adapts the volume so that it is correct. For the transmissions that are being rebuilt with smaller clearances it just means they require less volume of fluid to fill. I guess it could also mean that the clutch will fill faster and give a slightly quicker shift, but I don't know how the fill times are handled, maybe the TCM will adjust pressure to give a commanded fill time?
VE Calais V 6.0L L98 V8 6L80E
Did they mention Which clearances?
Pressure adapt is intended to look after variations in clutch fill requirements over the life of the trans in an effort to maintain consistency.
Clearly a glitch with yours though. Sad that the resources of GM/Holden were unable to make a difference, but in a few days of trying, you do!
Yeah I have it disabled now. In my trucks stock tune, it was enabled for every shift. So far no issues with having it disabled and the truck is shifting pretty good. Still noticing a little flare up every now and then. I too noticed the 2-3 shift being set at 40 in the max adapt volume table, but did not change it as I wanted to see what the discrete shift torque disable would do. I'll give that change a try too.
Thanks again to everyone for the valuable input!
2019 F-150 3.5 EcoBoost 4x4
Guys I've been following this thread and I just up'd the "Max Adapt Volume" as BlueSSV mentioned and all I can say is wow! I have a 2800 stall in my C6 and the days of chirping the tires into the next gear were gone. I just took it out for a spin and the tires broke loose on the 2-3 shift. It was a great feeling. The 2-3 shift is super smooth and crisp now.