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Discussion Starter · #1 ·
Hello, everybody!

Since I am looking into options to enhance my 5eat transmission - can anybody tell me - is it possible to reprogram transmissionc ECU(TCU)?
If yes - what can be reprogrammed exactly?

west_minist mentions working on 5eat, though without specifics (which is kinda understandable, since it is his business). also I read somewhere on drive2.ru that somebody has done some work on 5eat programmatically. But, again, without specifics.

TIA!
 

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I wonder if the romraider forums are still around. If so, might check that.
 

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Discussion Starter · #6 · (Edited)
line pressure is "tuned" (well, a bit) by switching to sport mode;) and that's not all it is possible.
right now I have recieved tuned valve body from Russia with enhanced switching times between gears, faster atf circulation (if you do trackdays or spirited/aggressive driving - helps to cool torque converter), faster PRND switching too.
from information I could find - some tuning is attempted here in States, but... not the best engineering to no differences found after opening and comparing it to original :D

as I mentioned west_minist(XRT) earlier - I am not sure what he is programming and is it in ECU or TCU.
regarding ECU - I tried already open source tuning from [email protected] forums - quite nice result plus I saw that even ECU changes affect even those details in cars behaviour which I though were transmission only.

in regards for that - anybody knows where in the States to get Mobil ATF 320? All I could find on google was in UK, but that ATF kind is for it's superior stability when heated (say - track day :D
 

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Discussion Starter · #7 ·
still not sure about anybody interested in this, but I have got [email protected]'s tuned valve body in my transmission. Hopefully, soon will sort out transmission learning procedure (which, unfortunately, cannot be done with FreeSSM or other enthusiast reachable software).
 

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The factory service manual explains how to do the transmission learning procedure. You wipe clean the learning #1 and #2 (you can do that with FreeSSM) and then have set acceleration steps (on jack stands?). Most say you can just wipe it and drive and it will relearn on its own.
 

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Discussion Starter · #9 ·
For my car I have found this - Screenshot
USDM Tribeca 2009 FSM\TRANSMISSION SECTION\AUTOMATIC TRANSMISSION DIAGNOSTICS 5ATdiag\10 Learning control.pdf

for 2006, however, I found this - Screenshot - this is what you are referring to?
Anybody knows how successfull it is on facelift (3.6) Tribecas? Will try it tonight, anyways
 

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Discussion Starter · #10 ·
sooo.
finally went to dealership to do learning for transmission.
Tuned valve body is a must for our cars. Even on stock ecu tune - it responds fantastic.
Will do some measuring tonight (fingers crossed for not being caught speeding :D
 

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line pressure is "tuned" (well, a bit) by switching to sport mode;) and that's not all it is possible.
right now I have recieved tuned valve body from Russia with enhanced switching times between gears, faster atf circulation (if you do trackdays or spirited/aggressive driving - helps to cool torque converter), faster PRND switching too.
from information I could find - some tuning is attempted here in States, but... not the best engineering to no differences found after opening and comparing it to original :D

as I mentioned west_minist(XRT) earlier - I am not sure what he is programming and is it in ECU or TCU.
regarding ECU - I tried already open source tuning from [email protected] forums - quite nice result plus I saw that even ECU changes affect even those details in cars behaviour which I though were transmission only.

in regards for that - anybody knows where in the States to get Mobil ATF 320? All I could find on google was in UK, but that ATF kind is for it's superior stability when heated (say - track day :D
I researched ATF specs till I was dizzy, and Mobil synthetic ATF was the only one I could find with the same viscosity @ 100c as Subaru factory fluid.
 

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Discussion Starter · #12 ·
For this tuned valve body - it's creator recommended higher viscosity - that was the problem. Since Idemitsu ATF HP is available - original specs are not an issue, higher viscosity is...

here is my turn with different ATF specs:
idemitsu atf hp
7.3

Yacco ATF 3,
7.4

Castrol Transmax ATF +4
7.4

Mobil1 Synthetic ATF
7.4

Petrocanada D3M,
7.4

Eneos D3,
7.4

Amalie ATF+4
7.5

Motul multi ATF,
7.6

Neste ATF-X,
7.7

Castrol Heavy Duty Multipurpose ATF
7.7

Mobil ATF 320
8.2

The lower in list - the better... but best I could find in USA - was Motul Multi ATF... when I asked local workshop guys about this issue and they looked by themselves - with stopped breathing they said that is for PORSCHE only! :D

Anyway - for now, I will continue use Idemitsu.
 

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I would think that less viscosity would mean less drivetrain losses and better MPG. Idemitsu seems to take the cake there although conflicting with that valve body preference.
 

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Discussion Starter · #14 ·
less drivetrain losses and better MPG is just one side of story. there are other things to consider - like overheating. in some situations (especially with original valve body designs) oil in torque convertor overheats since it has very little circulation - that is one of design upgrades done by him :)

guy who is making these tuned valve bodies told me little story when we spoke about different ATFs:
Since he is kinda knowledgeable with automatic transmissions (he makes tuned valve bodies for 4eat, 5eat 1st gen and 5eat 2nd gen) - he was called in for consult at some workshop, where strange things were happening. Whenever they changed ATF in subaru owner transmissions, subarus come back to replace transmissions in few month.
It turns out - workshop has big drum of Toyotas ATF (with viscosity around [email protected]), which they use on everybody........
 

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less drivetrain losses and better MPG is just one side of story. there are other things to consider - like overheating. in some situations (especially with original valve body designs) oil in torque convertor overheats since it has very little circulation - that is one of design upgrades done by him :)

guy who is making these tuned valve bodies told me little story when we spoke about different ATFs:
Since he is kinda knowledgeable with automatic transmissions (he makes tuned valve bodies for 4eat, 5eat 1st gen and 5eat 2nd gen) - he was called in for consult at some workshop, where strange things were happening. Whenever they changed ATF in subaru owner transmissions, subarus come back to replace transmissions in few month.
It turns out - workshop has big drum of Toyotas ATF (with viscosity around [email protected]), which they use on everybody........
Wow that is some story! Yes, you are correct CST at 100c variables are only one side of the story and that is thin. I concur with you. I dislike it on some forums where there is not consideration to MPG/HP on drivetrain losses on more flexible transmissions. Oh it's only 1 billionth of a HP or 1 trillionth of a MPG. In this case though, no way would I risk it.
 

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Discussion Starter · #16 ·
to talk about drivetrain losses - I need to be way more knowledgable + transmission needs to come out to be measured (and adjusted and fixed).
I think it is in pretty worn shape and I hope in future to fix it, but for now - I will play with what I have :D
for now - main goal for me - is to make the car perform better in terms of acceleration, braking and joy :D
 

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Discussion Starter · #17 ·
anyway, last night did some tests, which were not really conclusive, but I would say that tuned valve body removed about 1second from 0-100mph (roughly 24sec stock, 23sec now - with tuned valve body) and about 0.2sec from 0..100km(roughly 0-62miles).
subjectively - transmission is more responsive and "feels lighter" :D
that is purely hardware modding.
there still are ways to enhance this, but next(for me now) will be ecu tuning.
 

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For this tuned valve body - it's creator recommended higher viscosity - that was the problem. Since Idemitsu ATF HP is available - original specs are not an issue, higher viscosity is...

here is my turn with different ATF specs:
idemitsu atf hp
7.3

Yacco ATF 3,
7.4

Castrol Transmax ATF +4
7.4

Mobil1 Synthetic ATF
7.4

Petrocanada D3M,
7.4

Eneos D3,
7.4

Amalie ATF+4
7.5

Motul multi ATF,
7.6

Neste ATF-X,
7.7

Castrol Heavy Duty Multipurpose ATF
7.7

Mobil ATF 320
8.2

The lower in list - the better... but best I could find in USA - was Motul Multi ATF... when I asked local workshop guys about this issue and they looked by themselves - with stopped breathing they said that is for PORSCHE only! :D

Anyway - for now, I will continue use Idemitsu.
I have always used Castrol products, and prefer them, but their ATF viscosity dropped off at 100c.
 
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