TCC Tuning! TCC Lock 3rd at WOT?

[EagleMark]

Been doing some trans tuning for awhile with great results, pretty easy to completely change how a vehicle feels and drives. Take away the BIG SLUSH and make it feel like you actually have gears!

So started reading some of the threads here with great info:
http://forum.efilive.com/showthread....hlight=tcc+pwm
http://forum.efilive.com/showthread....hlight=tcc+pwm
Best post but read entire thread:
http://forum.efilive.com/showthread....ll=1#post16583

On to my problem. Can't stop TCC Lock up in third gear at WOT?

Here's a log, .tun and even a dashboard with monitor set up in "B" (can't seem to upload a dashboard set up?) to see the issue starting at 180, I let off after a short bit when TCC locked up, it's consistent so I got a log of it.

Maybe I missing something simple?

[EagleMark]

Main goals of this thread and questions are to reduce wear from slipping and decrease heat from slipping. Without causing undue stress or wear on tranny. To produce a good tranny tune for feel and drive ablity of vehicles.

Second question?

TCC PWM Duty Cycle D2903 min and D2904 max. I've read a few times to decrease wear and heat that the max should be 99-100 % and min should be lower but only a little bit. Basically keeping full duty cycle to avoid slip.

Did a log with stock setting which max was basically 98% and the mins were as low as 10% up to 21%. During Lock Up there was no slip, well 1-2 RPM and duty cycle would change to low numbers like 40%. Even when hard acceleration there was no slip, eventually the TCC was unlocked where it should have by TPS% setting.

Increased the min to be 96% with max at 98% and still no slip but duty cycle did stay high. Is this even needed then? Is this causing an undue strain? Data logs show the TCC Duty PID GM.TCCDC at max of 98% long before TCC is Applied, when locked goes much lower.

This is my first time adjusting these settings and I see no results?

[EagleMark]

D2905 TCC Pressure Apply Rate.

Have not tested this one yet but may have time today.

Looks like it is used to slow/slip/smooth/slush TCC while being engaged. In my logs I have as much as 1.2 seconds to lock up Converter with PID GM.TCCTIME

[EagleMark]

Understanding GMTFMPRS Pressure control Solenoid Pressure. It's been noted to use this in tranny data logs but I see no correlation to it's raising and lowering pressures? So I don't understand what it's purpose is?

[Wheelz]

Subscribed.

I wouldn't mind helping figure out what these are, ill be more help when I get back home to an Internet connection tho. Kinda difficult reading tunes on a phone at this time :haha:

[Taz]

Hi Mark,

Give the attached tune a whirl. TCC should engage a little more positively than before. To unlock the TCC in third gear based on %TPS adjust D1008 - you will notice I adjusted the cells above 60 MPH to unlock at 88% TPS (which is the lower threshold for your %TPS = WOT settings).

Also, just my opinion, but your Desired Shift Times are a little bit quick at low %TPS and your Base Shift Pressures are a little bit low in general - with respect to a tune intended for "spirited" driving.


Cheers,
Taz

[EagleMark]

So you found an issue? Cool! Thanks Taz! I'll give it a whirl... and also look to see what I was doing wrong.

The desired Shift times have worked well, but as I follow some info in first post links like increased pressure and taking out some TM, I'm finding they may be to quick.

I've only added 10% to Base Shift Pressures so far and started to log as well as feel differences.

Tips and tricks are always appreciated. But I do them slow and verify, must also learn, not just punch numbers in!

[Taz]

... So you found an issue? ...

Not an issue ... the settings in the tune are typical ... trying to find a way to get the TCC to work the way you wish.

... and also look to see what I was doing wrong ...

Not doing anything wrong ... many different ways to arrive at a similar end.

I tend to leave TM at, or very near, stock levels. This keeps the transmission as safe as possible during shifts - and typically TM is only active for a fraction of a second.

I also tend to increase shift pressure to reduce potential slippage - which may also promote longevity.

Increased shift pressure also creates a firmer shift.

A balance must be struck between shift time and shift pressure - to create the desired driving feel, without sacrificing transmission longevity.

[EagleMark]

Hi Mark,

Give the attached tune a whirl. TCC should engage a little more positively than before.

D2905 TCC Pressure Apply Rate.

Have not tested this one yet but may have time today.

Looks like it is used to slow/slip/smooth/slush TCC while being engaged. In my logs I have as much as 1.2 seconds to lock up Converter with PID GM.TCCTIME

That was my next adjustment. You verified I was on right track there!

Hi Mark,
To unlock the TCC in third gear based on %TPS adjust D1008 - you will notice I adjusted the cells above 60 MPH to unlock at 88% TPS (which is the lower threshold for your %TPS = WOT settings).Cheers,
Taz

Had to look before a drive. But I wasn't trying to release, at WOT it should have never engaged? Based on WOT and D1002 settings... Going to give it a shot now.

I tend to leave TM at, or very near, stock levels. This keeps the transmission as safe as possible during shifts - and typically TM is only active for a fraction of a second.

I also tend to increase shift pressure to reduce potential slippage - which may also promote longevity.

Increased shift pressure also creates a firmer shift.

A balance must be struck between shift time and shift pressure - to create the desired driving feel, without sacrificing transmission longevity.

This is the balance I'd like to add! When ever I start doing something differant I like to do it slow, data, verify etc...

The Shift TM is one I have always stayed away from, but reading some other threads advice from reputable people I am making small adjustments there.

[EagleMark]

Hi Mark,

Give the attached tune a whirl. TCC should engage a little more positively than before. To unlock the TCC in third gear based on %TPS adjust D1008 - you will notice I adjusted the cells above 60 MPH to unlock at 88% TPS (which is the lower threshold for your %TPS = WOT settings).

Cheers,
Taz

Still got TCC Lock coming on third gear at WOT?

At other then WOT, just normal driving the adjustments made to engage TCC quicker and less slip worked very nicely. Cut times in half, can feel the lock nicely and nothing harsh.

Other adjustments in Shift Pressure and Shift times have improved dramatically! Drives very nice with nothing harsh. I even get tire chirp in 1>2 shift at WOT!