Full time lock up mode

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
gurov
Posts: 164
Joined: Mon Jun 01, 2009 1:01 pm

Full time lock up mode

Post by gurov »

does FULL TIME TCC lockup override "max. tcc load (kpa)" ?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Latest Code Updates

Post by Bernard Fife »

yes
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
gurov
Posts: 164
Joined: Mon Jun 01, 2009 1:01 pm

Re: Latest Code Updates

Post by gurov »

Lance wrote:yes
hmmm.. so with this, if full TCC lock engages at X rpm (engine) and the torque converter is slipping, wouldn't engaging TCC cause engine rpm to drop instantly to below that X rpm threshold, causing TCC to unlock and engine rpm to shoot up past the threshold.

perhaps that should be input shaft rpm for TCC lock ? so gas in, accelerating on torque converter, engine rpm at say 5000 in boost (or bouncing off the rev limiter in the ecu, which is another story, cause the trans code would probably actually shift here, dropping out of power band), converter is slipping doing it's torque multiplication thing, input shaft rpm is say 3500 and accelerating, once it gets to 4000 rpm, lock the TCC, engine rpm drops down to around 4000, still in boost and continues on the locked clutch

i am enabling input shaft rpm pickup as a sensor again (i will see whether it's still causing issues with VSS), but the calculated input shaft rpm would still work for this.
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Latest Code Updates

Post by Bernard Fife »

gurov,

Yes, you are right, of course. I have fixed this in the 2.00D code just released: http://www.msgpio.com/manuals/mshift/V2code.html

This code includes a user specified speed to unlock the TCC once entering the full time tcc mode. The default is 4500 and the defualt rpm to enter full time mode is 5000. So full time mode would be entered at 5000 rpm, but wouldn't be released until 4500. User will have to set these values so that the spread is larger than the rpm drop when the TCC applies (typically only a hundred rpm or less when above the stall speed).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
gurov
Posts: 164
Joined: Mon Jun 01, 2009 1:01 pm

Re: Latest Code Updates

Post by gurov »

Lance wrote:gurov,

Yes, you are right, of course. I have fixed this in the 2.00D code just released: http://www.msgpio.com/manuals/mshift/V2code.html

This code includes a user specified speed to unlock the TCC once entering the full time tcc mode. The default is 4500 and the defualt rpm to enter full time mode is 5000. So full time mode would be entered at 5000 rpm, but wouldn't be released until 4500. User will have to set these values so that the spread is larger than the rpm drop when the TCC applies (typically only a hundred rpm or less when above the stall speed).

Lance.
i will try this out today to see what kind of rpm drop i get, but that does solve the problem of engine rpm dropping

i will also test the shift retard. is the duration of the retard the PC adj time + shift completion time ?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Full time lock up mode

Post by Bernard Fife »

i will also test the shift retard. is the duration of the retard the PC adj time + shift completion time ?
gurov,

Yes. Well, technically, it is those delay times plus the time required to process the instructions to switch the solenoids (but this would be very short compared to the delay times).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
gurov
Posts: 164
Joined: Mon Jun 01, 2009 1:01 pm

Re: Full time lock up mode

Post by gurov »

the PWM TCC high/low settings are confusing me. could you expand on how these relate to engagement of TCC.

if i set them 100kpa/100% 100kpa/100%, and set the engagement time in seconds, will that get me full engagement over that time ?

what variable is sent to TS for TCC PWM % ?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Full time lock up mode

Post by Bernard Fife »

gurov,

The high and low PWM% values (at the high and low load) define the starting values for the TCC PWM%. This will then taper to the 'PWM% when TCC Locked' over the 'PWM Taper Time' you specify.

So if you specify "100kpa/100% 100kpa/100%, and set the engagement time in second", the PWM% will start at 100%. If that is 'TCC off' and TCC on is 0% (for example), then the TCC will engage over the taper time, as you say.

However, if 100% is the 'TCC on' PWM%, then the TCC will be applied immediately with the settings above (because it starts at 100% = on), and there is no taper.

The TCC PWM status variable in outpc and the INI is lock_TCC.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
gurov
Posts: 164
Joined: Mon Jun 01, 2009 1:01 pm

Re: Full time lock up mode

Post by gurov »

Lance wrote:gurov,

The high and low PWM% values (at the high and low load) define the starting values for the TCC PWM%. This will then taper to the 'PWM% when TCC Locked' over the 'PWM Taper Time' you specify.

So if you specify "100kpa/100% 100kpa/100%, and set the engagement time in second", the PWM% will start at 100%. If that is 'TCC off' and TCC on is 0% (for example), then the TCC will engage over the taper time, as you say.

However, if 100% is the 'TCC on' PWM%, then the TCC will be applied immediately with the settings above (because it starts at 100% = on), and there is no taper.

The TCC PWM status variable in outpc and the INI is lock_TCC.

Lance.
so i could set it to 100kpa/50% 100kpa/50%, and the engagement would start at 50% and go to 100% over taper seconds ?

so after shift, say i'm at 120kpa, with high load of 110kpa/90%, engagement would start at 90%, and go to 100% over taper seconds ?

i'm not seeing 'PWM% when TCC Locked' setting, there's only PWM% when TCC is unlocked, and if that's set too high, i lose reverse, for whatever reason.
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Full time lock up mode

Post by Bernard Fife »

Gurov,

Whoops, you are right, of course, the 'ON' value when on was not in the INI, though it was in the code and manual (a technical f-up on my part).

I have added this, as well as the minimum speed setting to the INI. I have also moved the TCC setting to their own menu on the main page of TS, as it was getting hard to find it the TCC items. I have also moved the TCC PWM period setting from the solenoid setup to the TCC LOAD/PWM% Parameters menu (under TCC on the main menu). I have not updated the manual yet, but will do that shortly.

The INI is 2.00Dx here:http://www.msgpio.com/manuals/mshift/fi ... _200Dx.ini

The taper starts at the interpolated value set by the high and low low value and PWM%. It always ends at the "PWM% when ON" value regardless of where the high and low load values are set (because they are only the start values).

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
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