Any plans to add a downshift table?

[gross polluter]

Been trying to get the single table to work well with my setup for quite some time now and it just isn't working well with my trans. I currently have a 2JZGTE with an A340LE transmission, both from a 98 supra. The issue that I'm running into is that I'd like the trans to short shift on up shifts, but not downshift unless I really get in the throttle or the speed is significantly low for that gear. This is much like the stock operation of the supra. I either have to set the max shift RPM too low, or set the shift hysteresis too high. It would be a nice feature to have an second table for downshifts. Seems like it would be quite a bit easier to make the mshift code work with a wider variety of transmissions where the inherent design was to not always downshift as a specific upshift point like it currently does.

[Bernard Fife]

gp,

There are no plans to add a separate downshift table. The problem with shift multiple tables is that it is very easy for users to set them up with conflicting logic, and then their trans doesn't shift properly at all. If enough people wanted it and could explain precisely how they wanted it to work (and this was both logically consistent and user friendly), we would consider adding it, though.



The default shift table is set up so that at high loads the engine runs to the red line before the upshift, and downshifts as soon as the red line won't be exceeded. At low loads both upshifts and downshifts are at low rpms. This is what most people want and expect - including you, if I understand your post properly. If you shift table doesn't look similar to the above, you may have it misconfigured. For example, some people put the same value in an entire column, and this removes the load based shifting ability.

So the current table only has upshifts and downshifts at the same speed *IF* the load is the same, and that would be unusual in a real world application. If you are wanting to upshift early at low loads (to keep the revs low), you can do this by entering higher numbers in the lower part of the shift table. If you want to downshift early at high loads (to keep the revs high), then you can enter lower numbers in the higher part of the table. You may have to play with the load averaging settings to get the behavior you want, see the manual for details: http://www.msgpio.com/manuals/mshift/V2tune.html

There is a second, easy way to get the trans to downshift when you want, though: the shift buttons. If you want to upshift early, press the upshift button. If you want to downshift early, press the downshift button. That will get you the gear you want, and you will go back into auto mode when you press both buttons, drop below the minimum speed, or select one of PNR.

Lance.

[gross polluter]

Suppose I just need to get used to this strategy then. Shift buttons work fine for me, but if someone else is driving my car I'd like it to drive as "stock" as possible. I've been used to having separate up/down tables on AEM and PCS that having a single table with hysteresis is pretty new to me.

[mikeymkll7mgte]

Im running into the same problem with downshifts. If I set the shift table how I want it to shift with normal driving, I stomp on the throttle and have to wait for boost to build before it shifts (2-3 sec). But, if I setup the table to favor downshifts, the second I start climbing a slight incline and it builds any boost with light throttle, it tries to down shift like crazy, when it would have held the hill just fine in 4th. The stock transmission control for my transmission is throttle based, not map based. I know the one in gross polluters 2JZ is the same way. Is there any future plans of doing a TPS based map for guys like myself running boost that need more tps based rather than map?

[Bernard Fife]

mikey,

You can already use TPS for load on the shift tables with the existing code. You need to select it under "CAN Load Variable". See: http://www.msgpio.com/manuals/mshift/V22tune.html#oa

If you are not using CAN, you can use the 0-5V TPS signal for load. See "Non-CAN Load Settings: http://www.msgpio.com/manuals/mshift/V22tune.html#gc

(I have just corrected a typo in the INI and manual, so you may need to refresh your browser.)

Lance.

[mikeymkll7mgte]

Lance, I have tried that, and it stays as "Load kpa" on the shift tables, and still acts as it did using kpa. Am I missing something else?

[Bernard Fife]

mikey,

The labels won't change just because the value selected for the load is changed because of the limitations on the way TS and MShift interact.

You can change the label manually, if you like. To do this you need to unset LOAD_KPA. Use a text editor (like notepad or notepad++) to open the INI file. Search for a line like

Code: Select all

#  set LOAD_KPA

and change it to:

Code: Select all

#  unset LOAD_KPA

save the file and restart TS. Then the load label will be in percent (%).

Note that the various load values have been tested in B&G 2.905 and 3.780. Other codes may (or may not) report the MAP and TPS according to the B&G standard, and you would have to ask the developers if/why not.

Lance.

[mikeymkll7mgte]

Ok. Thanks a bunch. Ill give it a try in a bit and see how it does.

Im running MS3X V1.1.1 and MShift V2.2 so I hope it will work.