[cjperformance]

Originally Posted by grampa_ss

My settings: shift pressures/general/general Map pressure = 3,447 kpa
shift pressures/general/Base line pressure/TCC on - starts a 1,724 thru 3,609 for all rpms
shift pressures/general/Base line pressure/TCC off - starts 1,379 thru 2,694 for all rpms
shift pressures/upshift/patttern X,Y & Z 1st thru 6th - bump last 2 columns to 600

Torque Converter/General/TCC pressure/max pressure = 1,724 kpa
regulator gain 0.360
regulator offset 80.00 psi

I've been going over my logs and noticed something. If you don't command the converter to release...it won't (I think). I believe its locked by default?? Not positive, I'm just going by the logs.

In the Torque Converter/Apply/Release/Full Throttle: We had the release settings set to stock. We had the apply settings for 1-3 at 318, 4-7 were stock.
All my pulls were from a roll at 45mph. Converter stayed locked the whole time. My thinking is that since we never met the release parameters, the converter never unlocked.

I was trying some other apply/release settings and now my converter is slipping 1-3 and locking in 4th.
these settings are: release 1st, 2nd and 3rd set to 317
apply 1st, 2nd and 3rd set to 318.
so, 1-3 will stay released as all mph is under 317. and 1-3 will not lock as the mph is not over 318.

now my logs show the converter slipping until 4th...then it locks.

My TCC settings appear to be on par with yours. Tuner sent me a new config with some pressure changes, so we'll see if that helps.

[cjperformance]

Ok, so we increased the TCC line pressure to 200 psi and that seems to be doing the trick.

Getting lockup at WOT now.

[radz28]

Thanks to everyone for following up and sharing. I'm still learning, too. I left much of these settings alone, except for bumping pressures a bit, but knew there could be better strategies out there. Thanks for contributing everyone!

[KingLT1]

Originally Posted by cmitchell17

I tried all kinds of things to get mine to lock earlier and ramp faster. Unfortunately this is a common issue and HP Tuners unfortunately doesn't have the functionality we need with the correct table definitions available to properly control this transmission.

Mine ignores the command to lock right when it gets into second and doesn't start locking until the very end of second and it ramps pretty slow to where the ramp takes a couple thousand rpm's before it starts to couple, so its basically slipping through second, but about halfway through 3rd it finally locks.

I have never understood the argument of not locking the converter. With a stock converter its one thing as they slip less so the difference is probably negligible. Anytime the torque converter is unlocked you are wasting energy and diverting some of the horsepower that could go to your rear wheels to the torque converter slipping where it escapes as heat in your transmission fluid. All a torque converter is doing when it is slipping is acting like a lower continuous gear of about a 2:1 ratio that is proportional to the slip RPM so as its slipping your engine is revving up faster than your tires are revving up so you are trading a little bit of speed for more torque at the wheels.

This is helpful for the launch in first gear, but with our 8 and 10 speed transmissions we only need the torque convertor in first gear. If we still had 4L60s and powerglides it would be completely different and we would need to torque converter to provide that extra artificial gear ratio and help get the engine at a higher RPM where it has better volumetric efficiency.

I understand what you are saying but these 8/10 speed transmissions with stock converters drive much nicer not locking/unlocking every shift part throttle. Hence why I set them up to remain unlocked until final gear 60mph. Stock converter is really tight, and I like the throttle response with the little bit of rpm flair when you blip the throttle. You lose very little fuel mileage or efficiency this way.

With a higher stall I would probably consider locking the part throttle shifts again depending on how loose the converter is. WOT shifting, locked should trap higher, but that doesn't always mean you will run quicker. The 4-5 shift on a A8 drops quite a bit of RPM. So, would staying unlocked be "quicker" on a centri car that will drop 4-5psi on the 4-5 shift locked vs remaining unlocked and only dropping 2-3 psi on the shift? I haven't tested that but would be curious to know.

Side note, I assumed that you upped the line pressure when the converter was changed. That is tuning 101 really. High stall converters slip more until locked(if lockable). In order to get the clutches to grab they need more pressure applied.

[cjperformance]

Originally Posted by KingLT1

I understand what you are saying but these 8/10 speed transmissions with stock converters drive much nicer not locking/unlocking every shift part throttle. Hence why I set them up to remain unlocked until final gear 60mph. Stock converter is really tight, and I like the throttle response with the little bit of rpm flair when you blip the throttle. You lose very little fuel mileage or efficiency this way.

With a higher stall I would probably consider locking the part throttle shifts again depending on how loose the converter is. WOT shifting, locked should trap higher, but that doesn't always mean you will run quicker. The 4-5 shift on a A8 drops quite a bit of RPM. So, would staying unlocked be "quicker" on a centri car that will drop 4-5psi on the 4-5 shift locked vs remaining unlocked and only dropping 2-3 psi on the shift? I haven't tested that but would be curious to know.

Side note, I assumed that you upped the line pressure when the converter was changed. That is tuning 101 really. High stall converters slip more until locked(if lockable). In order to get the clutches to grab they need more pressure applied.

So... I had Rick Clarke rework my tune recently, and I dont have an apples-to-apples comparison, but now with it locked, I'm only dropping about 1.5 psi on the 4-5 shift. Depending on weather... 7.75 psi top of 4th, down to 6.25 in 5th.

I dont have any pulls where the converter was completely unlocked with the Rick Clarke tune for comparison. It just had a constant slip of 250 rpm.

I want to say with my previous tune which was completely UNlocked at WOT, I saw a 3-4 psi drop.

[KingLT1]

That sounds backwards from how it should be. Locked converter will drop to a lower rpm on the next gear vs unlocked and converter slipping to a higher rpm.

[cjperformance]

Originally Posted by KingLT1

That sounds backwards from how it should be. Locked converter will drop to a lower rpm on the next gear vs unlocked and converter slipping to a higher rpm.

I'll see if i can find some logs to post up later. The new tune has torque management turned off in the trans on shift, the old tune had tq mgmt enabled. I'm thinking the tq mgmt was causing the procharger relief valve to dump some pressure on the shift with tq mgmt on. Just a guess though. But in principle i agree with you, so i think it is more complicated for me than just the locked vs unlocked.

The only fair way to do this would be locked vs unlocked with the same engine tune.

[cjperformance]

I didn't have time to capture a bunch of screenshots, but I did look back through my old logs last night and compared with recent ones. Happy to do the legwork if specifically requested, but here's my conclusion.

In my case, with TCC *unlocked* and with torque mgmt *on* during a shift, there was a consistent 3 psi drop between gears in 90 degree ambient.

With TCC *locked* and torque mgmt *off* during a shift, there was a consistent 2 psi drop with same ambient temp.

What would it look like with TM off and TCC unlocked? I'm not sure.

I've concluded the difference is that there is also a noticeable dip in rpm with TM on during the shift compared to with it off... so final conclusion is that powering through the shift and the slight amount of wheelspin was what was really keeping the rpms and psi up through the shift. If I had DR's and no wheelspin... I bet I'd see more psi drop.

[grampa_ss]

So I've been going over my logs too. Unlocked, the rpm drop isn't quite as bad vs locked. Unlocked will keep you in higher boost & rpms during shifts. But at a price. You're slipping the converter and thats not putting it to the ground.

I ran back to back tests. I had "normal/tour" set to lock and "Pattern B/Sport" to unlocked. Both lock in 4th though.

**TM & Torque Reduction are disabled**

I did 40-110, 50-120. The converter locked was quicker everytime...barely. BUT...It was shifting early on the locked run. I was shifting 2-3 @ 61 mph and 3-4 @ 90 mph for BOTH locked and unlocked.

Here's an example of difference locked vs unlocked: taken from WOT pulls.
60 mph unlocked is 6369 rpms
60 mph locked is 5981 rpms
90 mph unlocked is 6646 rpms
90 mph locked is 6265 rpm

so you can see you need to set the shifting differently as with our cars, the shifts are based on mph and not rpm.

When the converter was Unlocked, it was perfect...shifting at about 6800-6900.
Locked it was shifting at 6500-6600...way early. So if I were to increase the 2-3 to 63 and the 3-4 to 93, there would've been a bigger difference in favor of being locked.

I do love the feel of driving around with the converter unlocked. So what I ended up doing is:
Set Tour to run unlocked for DD. WOT is set to lock in 2nd. why not
Set Sport to unlocked for DD. WOT set to unlocked until 4th for dig racing.
TUTD is set to locked (Stock apply/release settings) this is for roll racing, and set the shifting to 31/63/93/118

I really don't know when to lock the converter when racing from a dig. People seem to not want to share that info. My gut tells me to try to lock it in 2nd. Closest 1/4 mile track is many hours away, so kind of hard to test dig racing.

[cmitchell17]

Originally Posted by cjperformance

Ok, so we increased the TCC line pressure to 200 psi and that seems to be doing the trick.

Getting lockup at WOT now.

Which table number in HPT are we talking about here?

I haven't noticed any differences in any tables in the TCM besides of course the TM switches and the higher desired shift times.

[cmitchell17]

Originally Posted by KingLT1

Side note, I assumed that you upped the line pressure when the converter was changed. That is tuning 101 really. High stall converters slip more until locked(if lockable). In order to get the clutches to grab they need more pressure applied.

Also which table are you reffering to? Like the number, [TCM]5672 "Desired Pressure"?

I know this was a more recent table HPT added for this specific reason, I think others reported that it did work, but its not working for my OS.

[cjperformance]

Originally Posted by cmitchell17

Also which table are you reffering to? Like the number, [TCM]5672 "Desired Pressure"?

I know this was a more recent table HPT added for this specific reason, I think others reported that it did work, but its not working for my OS.

Yeah, desired pressure table. I dont have my tuning pc on hand so I dont know the table number.