5EAT "Mad Scientist" Idea & Test Thread

TCU test project: http://legacygt.com/forums/showthread.php/5eat-tcu-reprogramming-research-test-135697.html

Front LSD test project: http://legacygt.com/forums/showthread.php/5eat-front-lsd-fitment-test-134603.html

 

 

THREAD RULES: NO EXTRANEOUS POSTS

No lazy subscribes, no "wow very cool" posts, no "that is stupid though I have no data to back up my statement" posts

 

That's all. Keep it objective. Feel free to post ideas, links, test plans/results, anything that might be USEFUL.

 

If you know anything or have ideas about IMPROVING or MODIFYING the Subaru 5EAT (5-speed Electronic Automatic Transmission), please feel free to contribute.

 

Send me a PM if you don't know how to subscribe without posting.

To start, these are just ideas I have for getting into the 5eat.

 

As noted by LientenantComando, the TransGo shift kit is more or less compatible with our Jatco 5eat, very similar to the 350z and Titan tranny valve bodies. http://my350z.com/forum/engine-drivetrain-and-forced-induction-diy/462908-diy-transgo-valve-body-upgrade.html

He said his trans shop used the same kit on his Subi 5eat with success.

 

Another idea. Use a relay to tap into the 5eat Sport Mode switch, and use that to keep the engine on waste gate spring pressure unless you switch into Sport Mode (knock the lever to the left). Sport Mode supposedly changes the solenoid pressures and the shift mapping, and I believe this setting would be safer for going WOT with lots of extra power. Just thought of it, haven't explored the idea further than looking at the pin out and noting that it can be done.

 

Another idea: Identify the wires that run from the Valve Body to the TCU and tap into them with LEDs. I only know a little about electronics, so I would not be so good at going balls to the walls with this. But I see value in finding out if I could create a sort of 'shift light' that tells me when the trans is shifting (so I can reduce throttle a bit and help everything last longer). I also know several of you would like to tap into the torque converter lockup wire.

 

The idea of an aftermarket ATF temp gauge is an old one by now, but no one yet has tested temps in different places (pan vs hose to radiator vs return hose) to see what's going on. I don't know if any value would come from this, but I have the means and will be exploring this eventually. If someone wants to do it before me, please save me the trouble.

If anyone knows of a sort of 'bulkhead' style 1/8npt sender port that can be installed into a hole drilled in the side of the trans pan, that would be very helpful.

 

I will also be pulling apart my spare junked 5eat to see if a 5mt front LSD can be swapped in. If anyone wants to see something else in there once I have it apart, please let me know.

 

That's what I have for now. The 5eat has been a nice background project since I'm resigned to keeping this car. If work EVER slows down, I will certainly enjoy finding ways to make it work better for me/us.

Frankster's center differential bulletproofing thread, which would apply to the 5eat or anything else. http://legacygt.com/forums/showthread.php/5eat-center-diffrential-bulletproofing-122946.html?p=2831916

The sport mode does have a firmer shift , however when in normal mode the engine is cut through retard signal from tranny, so i am not dedicated on the fact that sport mode is better.

The transmission also sets pressure based on throttle, so it may be posible to increse transmission pressure through clever tuning. I'm not sure if the TCU looks at throttle angle, requested torque, or what though.

 

Seeing as this is the "Mad Scientest" thread, do any of you know what microcontroller the TCU and the valve body controller use? There is some good info out there on the 4EAT used in the SVX (it uses a Motorola controller I have experiance with), so if the design is simular we may be able to reprogram it.

 

When you dig into your spare transmission, could you look at the fluid path going to the ATF cooler? I'm still currious about when it sends flow to it, and when it's in lockup if any still flows. Speaking of cooling, the max temps in the transmission should be at the torque converter output. As it goes from there to the cooler (after some sort of valves) it should be hottest at the hose going to the cooler. Though getting a reading under lockup would depend on how it redirects fluid. depend on

Anyone consider trying this Level 10 shift kit?

http://www.levelten.com/New_Product_Level_10_Subaru_PTS_Valvebody_Kit_p/sub-ja210-15000.htm

Not sure if the tcu looks at tps it would make more sence that it looks at maf for the pressure control,

 

if you realy want to go mad scientist .. just go full manual using mirco switches like i did with my sunbird.

 

but i think the "hard ware" or spring is limiting the maximum pressure of the tranny because the ipt valve body upgrades seam to work well.

As you can see in the link that climberd posted, there is a video of after the install on the 350z. Sifts are lightening quick, and firm engagement. I wonder if that kit is possible to use on our 5eat

from detailes of that transgo kit i have enough to repete the process i will set this up on my spare tranny,

 

but fyi the 350 z makes less power so of coarse faster shifts and i think

there lighter also.

can some body pm him and ask him for scaned copys of the trans go instructions? but be hush hush about it

from detailes of that transgo kit i have enough to repete the process i will set this up on my spare tranny,

 

but fyi the 350 z makes less power so of coarse faster shifts and i think

there lighter also.

 

 

Seems like options are very limited and pricey for upgrading the VB on 5eat. Has anyone else performed the 350z mod or have any more info on the process involved?

No need to PM him.... Look what I found (this is for the "HD" version in the titan)

http://www.titantalk.com/forums/titan-faq-howto-area/107187-transgo-shift-kit-install-how.html

http://www.titantalk.com/forums/titan-performance-modifications/105444-transgo-re5ro5a-hd2.html

 

I think all of it is between those two post.

from detailes of that transgo kit i have enough to repete the process i will set this up on my spare tranny,

 

but fyi the 350 z makes less power so of coarse faster shifts and i think

there lighter also.

 

Let us know how it works out if you go through with it on your spare tranny.

No need to PM him.... Look what I found (this is for the "HD" version in the titan)

http://www.titantalk.com/forums/titan-faq-howto-area/107187-transgo-shift-kit-install-how.html

http://www.titantalk.com/forums/titan-performance-modifications/105444-transgo-re5ro5a-hd2.html

 

I think all of it is between those two post.

 

 

excelent ! will try this ! but i'm stuck in gainsville texas !

 

can some one who has extra time compile this stuff ?

Didn't see this info posted elsewhere but it appears that the Nissan kit part number being used is RE5R05A-HD2.

Not trying to ask anything stupid, so please don't rip on me but isnt our trans a Jatco JR507E — 5-speed medium/large. Acrording to wiki this trans is used in Nissan President, Nissan Cima, Nissan Fuga, Nissan Skyline, Nissan Elgrand, Nissan Fairlady Z, Subaru Legacy Turbo.

 

and the Jatco RE5R05A transmission is found in Nissan Frontier, Pathfinder, Armada, Xterra, and Infiniti G35, Q45, M35, M45, CX35, FX35, FX45, and QX56 models

 

so wouldnt the valve body be different from one another since its two different transmissions?

 

http://en.wikipedia.org/wiki/List_of_Jatco_transmissions

 

With all this said it looks like we can finally go over the 500awhp marker with if we do the same thing frankster's center diff bulletproofing and the ipt torque convert service? Yes? No?

Not quite. All of these are based on the JR507E, but are set up for their seprate applications. For instance, the "HD" version is a bit bigger and holds more fluid then the normal version.

 

IPT would be the best to ask about the real diffrences, as they work on all of them.

IPT doesn't know. I have asked them. They will tell you they are very similar to the Infiniti G/Nissan Z and somewhat to the Titan units. I have contacted JATCO and SOA and the best information I was able to gather was that JATCO supplies all the parts and FHI mods them in-house to their own needs.

What is important and relevant to us ultimately, I think, is the quality/specs of the gearsets and clutchpacks. Which seem to be the same or very similar to the cars I just mentioned. If you consider their engine power's output, we can get a close estimate to the max torque-load rating of our transmissions. Which by the way is a very closely-guarded secret apparently. Nobody wants to tell us numbers because of fear it may come back and bite them in the ass ("You guys told me this tranny would hold xyz lbs-ft. I am under that number but my tranny still broke. Wah wah wah!"). I tried to get the specific specs, but I was ultimately unable to. JATCO, FHI, IPT, SOA, TransGo, nobody wanted to tell me or knew.

In the 4R70W by Ford, there's a DIY shift kit called a JMOD. It consisted of dropping the VB and enlarging specific holes in the shift plates by small amounts around .05" If we could figure out which circuit does what in the VB, its possible we could use small enlargements in the holes on the shift plates (if there are any) in the 5EAT to acquire the same result

Not quite. All of these are based on the JR507E, but are set up for their seprate applications. For instance, the "HD" version is a bit bigger and holds more fluid then the normal version.

 

IPT would be the best to ask about the real diffrences, as they work on all of them.

 

In theory yes. But the basics are the same. Also, the Titan has more power and torque on their 5eat. The basics of the valve body are the same. If the sane kit works for the Titan and 350z it should work for us. Someone should contact trans shift and see if the applicibility applies to us also.

In the 4R70W by Ford, there's a DIY shift kit called a JMOD. It consisted of dropping the VB and enlarging specific holes in the shift plates by small amounts around .05" If we could figure out which circuit does what in the VB, its possible we could use small enlargements in the holes on the shift plates (if there are any) in the 5EAT to acquire the same result

 

The instructions for the 350z kit require that certain holes be drilled in the VB. Maybe these are the same as the ones you are referring to?

From talking to my transmission shop the 350Z kit as you would order it from TransGo would be a NoGo. The transmissions are very similar. However, he works with TransGo and tests some of their products, so he was able to work with his contact to get whatever parts he needed adjusted along with making some tweaks of his own.

 

But TransGo doesn’t put together a package just for the Legacy because there isn’t enough of a market. He said nobody should try this on their own, as he has been doing it for 30 years. TransGo does work with a lot of shops throughout the country though and may be able to recommend a local shop if someone wanted to go this route.

Also to be able to fit in the extra clutches for 4th and 5th gear, he had to machine a piston to make enough room for them.

 

Went back for my 15 day warranty inspection, fluid level was good, he took it for a quick test drive (20psi quick!), and everything seems to be working great. He said its enough to make a grown man cry.

 

My mad scientist idea would be to setup some type of throttle position switch and connect it into the same circuit as the downshift paddle shifter on the steering wheel. That way instead of hitting the paddle shifter, you could just cause the transmission to downshift sooner by depressing the accelerator normally, but the shift would occur much sooner. Naturally you need a switch to deactivate (open the circuit) as well. It seems simple enough in theory, probably too simple to work though.

Hey guys.. My name is paul, I work at the shop where LT. columbo had his transmission built. if you guys really want some info on what we did for him, or if you would like to send us your transmission, we could take care of your build needs as well.

 

Let me start off by saying that this isnt just some extra clutches thrown into the transmission, we also built his converter, and did some custom VB work as well. this is NOT a plug and play shift kit.

 

and please dont give me a hard time for having an audi, because I LOVE subaru's...

Hey guys.. My name is paul, I work at the shop where LT. columbo had his transmission built. if you guys really want some info on what we did for him, or if you would like to send us your transmission, we could take care of your build needs as well.

 

Let me start off by saying that this isnt just some extra clutches thrown into the transmission, we also built his converter, and did some custom VB work as well. this is NOT a plug and play shift kit.

 

and please dont give me a hard time for having an audi, because I LOVE subaru's...

 

Very glad to hear this. Based on the very positive reviews from LieutenantCommando, proper marketing will earn you a decent amount of business from this forum, and perhaps from the 08+ WRX guys. There is almost no transparency from IPT regarding what exactly gets done to our transmissions with their $$$$ build, which is a downer. Good detail information from you could do wonders. I'm one of several who needs to send my trans somewhere, so we'll be in touch.

Thank you for posting, and I have an Audi too so no worries

What we did to LT. columbos transmission is not a secret, it wasn't easy but there is no reason to keep it a secret. I will get an exact breakdown of what we did for you guys this week. And i will tell you this.. from what i know about IPT, they arent really doing anything in their $5000 tranny job, the parts they are using are just stock parts for the 5eat, i'm pretty sure it would cost you about $650 in parts to build an ipt unit with what they use, they are just hopeing that your transmission dosn't fail right away. And if it does fail, its still not costing them very much to rebuild it again, they will still be making a profit. I also was not very impressed with the IPT valve body that I installed for LT. columbo, especially when his tranny took a shit on him so soon after.