6L80E Shift Pressure Questions

[TYRFRYR]

I have some general questions about the Shift Pressure section of the 6L80E Transmission tune.

In the Shift Pressure section there are:

• Max Pressure
• Max Pressure B
• Max Clutch
• Max Line Pressure Table
• Base Shift Pressure Tables

I've noticed in several OEM tunes, that the Base Shift Pressure Tables often have pressures significalty greater that the values in the Max Line Pressure table.

Case in Point. A Stock G8 tune has the following:

Max Pressure = 109.9
Max Pressure B = 275.6
Max Clutch = 217.6

Max Line Pressure Table (highest value) 105.3 (not including reverse)

Several of the Base Shift Pressure tables have 180 psi and higher.

Based on the the numbers in the stock tune, the only "MAX" value that makes any sense is the Max Pressure B.

Can somebody shead a ray of light on exactly what the different "Max Pressure" values/tables actually do.........

[TYRFRYR]

Ok. Well after some "light reading" (GM A6 Patent Application) I have seemed to answer some of my questions.

1. Max Pressure - Limit/Clamp on the values in the Max Line Pressure Table
2. Max Pressure B - Limit/Clamp on the values in the Base Shift Pressure Tables
3. Max Clutch - Limit/Clamp on the TCC Pressure Table

So.... Now the question is:

How are Max Line Pressure and Base Shift Pressure related to each other?

It appears as though Max Line Pressure is controlling the feed pressure to the Force Motor Valves (62,64) which generate the Pressures commanded by the Base Shift Pressure tables.

If this is the case, what is the typical max gain achieveable by the force motors???

[G8-4-speed]

Don't mess with the Max Line Pressure table. I can't tell you why but don't. The Base shift pressure and pressure preset tables seem to have a noticeable effect.

No matter how high you go, you still hit the mechanical pressure limit of the pump which is around 250psi.

[TYRFRYR]

... you still hit the mechanical pressure limit of the pump which is around 250psi.

That actually makes sense of what I've noticed. I couldnt notice any improvements past 245 psi.

[thesubfloor]

Don't mess with the Max Line Pressure table. I can't tell you why but don't. The Base shift pressure and pressure preset tables seem to have a noticeable effect.

No matter how high you go, you still hit the mechanical pressure limit of the pump which is around 250psi.

Well I certainly have no problem telling you why - IT'S BECAUSE THERE'S BEEN A TRANSMISSION-KILLING BUG IN THE BETA EVER SINCE IT FIRST CAME OUT BUT FOR SOME UNKNOWN REASON NOBODY AT HPT SEEMS TO CARE!!!

I've been a software developer for 23 years now and can speak firsthand that if I allowed the kind of crap software to be released like the beta has been (almost from the very first time it came out) I would have been fired a LONG time ago. I know full well the purpose of a beta program is to try and work out bugs and test drive new features with the public's help but c'mon, let's get real shall we?

Rather than try to add all these stupid new features which nobody wants, how about getting what's already in there working properly? How about releasing a scanner that will actually allow you to start and stop recording more than once without having to restart it almost every time? How about fixing it so it doesn't say it's scanning while it just sits there doing absolutely nothing? How about you guys stop asking for VCM Suite Infologs to try and placate us when you never ever do any followup on them?

Quite simply you should be ashamed of yourself as a company on the whole.

In regards to the Max Line Pressure table bug it can and has killed more than a few transmissions because the minute you change even a single value in that table it corrupts all the other stored values and can potentially end up sending too little line pressure in a given situation when what you really want is more.

Every single time a new beta comes out the very first thing I do is check to see if they've fixed the bug but I eventually gave up because despite repeated e-mails to Bill regarding this issue I continued to get blown off over and over again.

Since they'll never tell you how to recreate the bug (or probably even admit it exists for that matter) send an e-mail to [email protected] and I'll respond with the exact steps on how to recreate it.

If at all possible I would strongly recommend against using the beta (which I steadfastly refuse to do) especially if you plan on making any changes to the line pressures because it really is not a question of if but when your transmission eventually blows up because of it.

[IDRIVEAG8GT]

I can tell this thread is going to be full of win. I always wondered why there was a Max Pressure table. Can we rally to have some of the features that can potentially screw up our trannies taken out, and in place give us tables (Commanded Pressure All Gears, and then the rest of our shift tables with a more simple shift inertia configuration.) Boom problem solved.

[8850]

Just opened a file, made a change to my Max Line Pressure table and then saved it to another file name. If you do a compare then with the two files and try to a Copy Over you get a Set Table Cell box with an ID: 15581, unable to convert units message. Sounds like thesubfloor may be right about pressures having some determental effect as there is something going on with pressures.

I know I have had problems with getting my scanner to start scanning with 2.23 without xing out and starting over. Hopefully these problems will be corrected soon. At the track it's more of a problem than testing on the street. The guy at the starting line is too impatient to wait for me to get it logging after I've finished my burnout. Not to mention unfair for the guy next to me that's waiting having already done his burnout. I now always use 2.22 at the track and set up files in 2.22 so I don't have this problem.

[madvette08]

I understand the problem with doing a compare and copying over the Max Line Pressure table to another tune. I'm wondering if a pressure gauge was used to verify this problem with just changing the table. I have tested changing the Max Line pressure table with my vehicle and downloaded the tune with two other software suites, SCT and EFI Live and i have found that the data is the same each time.

[beav626]

looks like I will be going back to my stock tune and adjusting those values and leave line pressure alone.

[Sam88gta1]

Its about time someone said something about it.

Nothing bothers me more than the scanner starting and stopping then causing the Can Bus error.
This seriously needs some attention.

[B&Vperformance]

So has this been confirmed by many people that messing with line pressure values will cause trans problems?

[adriand]

Well I certainly have no problem telling you why - IT'S BECAUSE THERE'S BEEN A TRANSMISSION-KILLING BUG IN THE BETA EVER SINCE IT FIRST CAME OUT BUT FOR SOME UNKNOWN REASON NOBODY AT HPT SEEMS TO CARE!!!

I've been a software developer for 23 years now and can speak firsthand that if I allowed the kind of crap software to be released like the beta has been (almost from the very first time it came out) I would have been fired a LONG time ago. I know full well the purpose of a beta program is to try and work out bugs and test drive new features with the public's help but c'mon, let's get real shall we?

Rather than try to add all these stupid new features which nobody wants, how about getting what's already in there working properly? How about releasing a scanner that will actually allow you to start and stop recording more than once without having to restart it almost every time? How about fixing it so it doesn't say it's scanning while it just sits there doing absolutely nothing? How about you guys stop asking for VCM Suite Infologs to try and placate us when you never ever do any followup on them?

Quite simply you should be ashamed of yourself as a company on the whole.

In regards to the Max Line Pressure table bug it can and has killed more than a few transmissions because the minute you change even a single value in that table it corrupts all the other stored values and can potentially end up sending too little line pressure in a given situation when what you really want is more.

Every single time a new beta comes out the very first thing I do is check to see if they've fixed the bug but I eventually gave up because despite repeated e-mails to Bill regarding this issue I continued to get blown off over and over again.

Since they'll never tell you how to recreate the bug (or probably even admit it exists for that matter) send an e-mail to [email protected] and I'll respond with the exact steps on how to recreate it.

If at all possible I would strongly recommend against using the beta (which I steadfastly refuse to do) especially if you plan on making any changes to the line pressures because it really is not a question of if but when your transmission eventually blows up because of it.

Question about the max pressure setting in the beta version. When I view the max pressure value in the beta it shows 109 but when I look at it in version 2.22 it shows 276. The tables in both are the same but the max pressure is different depending on the version. If the table is set to 200 but the max pressure is only set to 100 will hit hurt anything over time? I understand I can just change the value but why would the same tune show different values in different software versions?

[Phil'sC5Vette]

I just spent $500 on a new computer thinking my computer was to slow for the scanner. Are you saying its the program that keeps freezing the scanner?

Well I certainly have no problem telling you why - IT'S BECAUSE THERE'S BEEN A TRANSMISSION-KILLING BUG IN THE BETA EVER SINCE IT FIRST CAME OUT BUT FOR SOME UNKNOWN REASON NOBODY AT HPT SEEMS TO CARE!!!

I've been a software developer for 23 years now and can speak firsthand that if I allowed the kind of crap software to be released like the beta has been (almost from the very first time it came out) I would have been fired a LONG time ago. I know full well the purpose of a beta program is to try and work out bugs and test drive new features with the public's help but c'mon, let's get real shall we?

Rather than try to add all these stupid new features which nobody wants, how about getting what's already in there working properly? How about releasing a scanner that will actually allow you to start and stop recording more than once without having to restart it almost every time? How about fixing it so it doesn't say it's scanning while it just sits there doing absolutely nothing? How about you guys stop asking for VCM Suite Infologs to try and placate us when you never ever do any followup on them?

Quite simply you should be ashamed of yourself as a company on the whole.

In regards to the Max Line Pressure table bug it can and has killed more than a few transmissions because the minute you change even a single value in that table it corrupts all the other stored values and can potentially end up sending too little line pressure in a given situation when what you really want is more.

Every single time a new beta comes out the very first thing I do is check to see if they've fixed the bug but I eventually gave up because despite repeated e-mails to Bill regarding this issue I continued to get blown off over and over again.

Since they'll never tell you how to recreate the bug (or probably even admit it exists for that matter) send an e-mail to [email protected] and I'll respond with the exact steps on how to recreate it.

If at all possible I would strongly recommend against using the beta (which I steadfastly refuse to do) especially if you plan on making any changes to the line pressures because it really is not a question of if but when your transmission eventually blows up because of it.

[Sam88gta1]

I just spent $500 on a new computer thinking my computer was to slow for the scanner. Are you saying its the program that keeps freezing the scanner?

Yes it is the scanner causing the problem. I have two new laptops and two pro cables and both of them have the same problems with the scanner.
Dont bother asking [email protected] about it. You will get a general response wanting you to read through useless help files.

[mgoodbar]

UMMM ok glad i did not mess with my 4 day old L99 camaro. ( they need to fix this.. man 500 for hp and 500 for a lap top... dude id be pissed.. just my 2 cents..

[Phil'sC5Vette]

UMMM ok glad i did not mess with my 4 day old L99 camaro. ( they need to fix this.. man 500 for hp and 500 for a lap top... dude id be pissed.. just my 2 cents..

Nope not pissed. Ive been using HPT for about 9 years. I can live with a bug or two, im happy to know its a bug rather than my computer.

I get a new tuning laptop every year with a little more speed, It just part of the business.

[Bill@HPTuners]

Question about the max pressure setting in the beta version. When I view the max pressure value in the beta it shows 109 but when I look at it in version 2.22 it shows 276. The tables in both are the same but the max pressure is different depending on the version. If the table is set to 200 but the max pressure is only set to 100 will hit hurt anything over time? I understand I can just change the value but why would the same tune show different values in different software versions?

this was discussed here: http://www.hptuners.com/forum/showthread.php?t=18561

older versions were displaying the incorrect pressure value.

[Bill@HPTuners]

I understand the problem with doing a compare and copying over the Max Line Pressure table to another tune. I'm wondering if a pressure gauge was used to verify this problem with just changing the table. I have tested changing the Max Line pressure table with my vehicle and downloaded the tune with two other software suites, SCT and EFI Live and i have found that the data is the same each time.

Yeah from what I've been explained is that its a units bug on the software side of things not a definition or table address bug as has been inferred in this thread.

-Bill

[Bill@HPTuners]

How about you guys stop asking for VCM Suite Infologs to try and placate us when you never ever do any followup on them?

Quite simply you should be ashamed of yourself as a company on the whole.

This isn't something we make up to get you frustrated http://www.hptuners.com/help/index.h...mersupport.htm its something we necessitate any time you contact support, you can't imagine how many times I have customers email us saying they have the newest software and are running 2.1.14 or something from back in 2006, an infolog shows me this information as well as the serial number of your interface, the year/make/model of the vehicle I'm dealing with, the operating system or custom operating system that I'm looking at, etc. So rather than going back and forth for 3 or 4 emails to get all of that information it takes 1.

-Bill

[Keith@HPTuners]

I'm going to try to fix the bug mentioned in the next few days.