5EAT Ask your Questions!?!

[Plague47]

The engine is freshly rebuilt and the tune is also brand new. Originally when I reinstalled the engine the torque converter was causing the car to stall when I came to a stop, the lockup had seized engaged. It still did the hesitation when starting from a stop too, regardless of whether the engine/transmission is hot or cold. I replaced the torque converter with a brand new one and the hesitation still continues, it wasn't cold before I replaced the TC so I can't say if the stalling in reverse is new or not.

 

It's worth it to say that the stalling in reverse happens only on the first cold start and only happens 1 time. It also happens when I'm not giving the car any gas, since I can simply drift backwards out of my spot. Idle has been bumped to 1000 when in park and 800 when in gear, so idle is plenty high. The car is also fairly heavily modified, it has full bolt ons, a vf52 turbo and forged pistons. Everything is brand new down to the coil packs and spark plugs too.

 

I have done a log of it when I first start it and I've seen nothing that points to any issues with the tune or engine, I'll capture another one and post it when I can, I'll also do the same but with pulling backwards into my spot so I can pull out forwards.

 

I do also have a GFB blow off valve, but it's set for full recirculation.

 

Some further information, the hesitation definitely feels like something is physically holding the car back, like if you leave the parking brake on by accident. Is it possible that it has something to do with the brake band in the transmission? I know these can get worn down pretty badly.

[Plague47]

Of course it didn't stall when I tried to log the stall, but here's two logs of the hesitation.

 

Now that I think about it, I've had this hesitation for as long as I can remember. No matter how much gas I give it it still accelerates at the same extremely slow speed until it gets to about 3000 rpm and then it takes off.

Also, When it does stall out when I'm reversing, I can feel it about to happen. As I'm drifting backwards and it starts to stall I can hit the brakes and it'll recover. When I continue to reverse it'll try to stall again until it eventually does. Once it stalls though, there is absolutely no signs of it trying to stall anymore, like it flips a switch and the problem is gone.

romraiderlog_20170222_113836.csv

romraiderlog_20170222_113951.csv

Edited February 22, 2017 by Plague47

[utc_pyro]

http://i.imgur.com/DHIaL0E.jpg

 

Fahr_side appears to be correct, looks like a low pressure drip getting blown to the back of the car.

 

UV die is showing up around the transmission pan, so it looks like they didn't seal it up properly post valve body install. There is also a lot of fluid around the joint where they pulled the center diff apart, but no dye is showing there so it was likely blown there.

 

Following up incase someone runs into a similar issue. Pan leak was double confirmed today when the dealership fixed it. Apparently the shop that swapped in the trasngo valve body screwed a few thing up; one of the valve body bolts was sitting on the bottom of the pan

 

Guy that did the work noted "test drove vehicle and transmission shifts rough"

[snow05gtRI]

hahaha... it's funny, if you don't know how to drive it with the TransGo/HexMods VB, that is the common response of "shifting rough." you really have to learn how to play the throttle/rpm game when you get the snappy shifts, otherwise it kinda clunks together.

[MTBwrench]

So my trans developed this weird noise over the last three days... it squeals. Only does it in sport mode whilst accelerating or decelerating, and at speeds of 50+mph when accelerating/decelerating.

 

I don't even know how to approach this sort of issue...

 

 

Sent from my iPhone using Tapatalk

[snow05gtRI]

as in, it sounds like a belt squeal?

 

I noticed a number of years ago that if I would hammer on it in "Sport" (not manual mode) that it would sound like a belt squeal between shifts (not sure if it was even all of the shifts). It never happens in manual mode, and I never hammer on it in Drive.

 

Sport mode offers increased line pressure in the trans, but not as high as manual mode. It may be not enough line pressure to handle what you're putting through it?

 

Check your trans fluid level.

 

Because of this, I never drive in Sport mode unless I'm just cruising on the highway.

[utc_pyro]

Been playing with my target boost tables, and I've noticed what seems to a correlation between target boost and shift firmness. Mainly lowering the target boost makes the whole thing shift a lot softer, as in non-modded valve body soft. This is with WGDC capped and TD disabled so it's not changing actual boost, just calculated boost error.

 

I've never seen any documentation that suggest target boost is published on the the CAN bus, nor does the factory service manual list it as an input to the TCU logic. Thus I'm not sure HOW this would influence shift behavior unless it's tied into the calculated torque logic.

 

Throttlehappy mentioned something about this a while back on RomRaider, but has anyone had similar observations? Or am I just correlating things that actually are unrelated?

Edited April 8, 2017 by utc_pyro

[west_minist]

The TCU takes inputs from the ecu based on engine load, throttle, rpm and engine estimated power. There will be a few other inputs, but those are what are critical to your venture.

[G5892]

Any new developments in decreasing the shift input lag, or getting the torque converter to lockup quicker/easier?

[Leftcoast_LGT]

^^^i would also like to know

[utc_pyro]

Any new developments in decreasing the shift input lag, or getting the torque converter to lockup quicker/easier?

 

A few of us are digging into the former right now. Sasha and roadie have gotten the furthest, but no one is anounced finding the counters.

 

TC lockup changes have been acheaved via the calculated torque tables. Untill we get further into tearing the TCU code apart it's kind of guess and check to get whatever you're looking for. Theottlehappy clamed to have seen the table structure from a TCU memory dump, but he never shared this and his post history is gone.

[Bigwillystyle]

Utc-Pyro.. Anywhere we can have a good chat with a few of the guys hacking on the tcu in one place?? I've got some ideas and access to a brain much smarter than mine to hack on this thing..

[NSFW]

I have a licensed installation of IDA, and if someone can get me a firmware image and the .idb or .idc of what's known so far I'd be happy to see what else I can find.

[utc_pyro]

Utc-Pyro.. Anywhere we can have a good chat with a few of the guys hacking on the tcu in one place?? I've got some ideas and access to a brain much smarter than mine to hack on this thing..

 

 

Roadie08 and Sasha have gotten the farthest over on romraider. I fought with it for a few weeks trying to get it to fall apart. The bootloader isnt actually in the code Sasha dumped, so it's hard to get things to work as an IDA noob.

 

I have a licensed installation of IDA, and if someone can get me a firmware image and the .idb or .idc of what's known so far I'd be happy to see what else I can find.

 

I can send you what I have, but it's basically nothing . I think Roadie08 was starting to pull apart the SSM commands, so he might have some defined memory location already.

[Golferdude1087]

Has anyone tried it via the Nissan platform? The 5EAT is virtually the same transmission which was found in the 03-06 G35, and IIRC that transmission did not have the same hesitation the subaru 5EAT did. Yes they changed some parts in later revisions, but the 05-07 trans are identical. Maybe the Nissan guys or someone using a G35 has found a way to unlock it and we can potentially use that to help on our end??

[utc_pyro]

Has anyone tried it via the Nissan platform? The 5EAT is virtually the same transmission which was found in the 03-06 G35, and IIRC that transmission did not have the same hesitation the subaru 5EAT did. Yes they changed some parts in later revisions, but the 05-07 trans are identical. Maybe the Nissan guys or someone using a G35 has found a way to unlock it and we can potentially use that to help on our end??

 

 

 

That's where the Hexmods/Transgo shift kits came from actually. They were originally developed for the 350Z/G35 and were adapted to our box.

 

It's really just a software issue, and having people with enough time and experience to pull it apart. Then from there is it something can can just modify the tables that are there (what most of the Subaru community does) or do you extensively rewrite parts of the code to get the functionality you want (seen often with German platforms).

 

There is a lot of new development coming out of Russia (including new flashing tools for more platforms) but not much in English.

[Bigwillystyle]

Hey does anyone know how to get in contact with frankster? I'd like to have a chat with him about the megasquirt system he's running..

[amp583]

2008 LGT 5EAT throwing a P0700 Turbine Speed Sensor 2 error. Is the sensor itself a replaceable item by re-soldering or do I replace the entire valve body? If the latter, where is the best place to aquire one? I'm guessing the dealer will ream me with an OEM.

[JazzAvi8r]

welp, I was at the Dyno yesterday. engine passed the smoke test and diagnostics. got the car strapped down, dyno calibrated, and did one WOT 3rd gear pull. P0700 and another code about the cam position sensor. car will start, but wont drive more than a minute before it shuts itself off. then I have to wait some time before the car will start again. Prior to the P0700, the trans worked great in Drive, but was laggy and rough in the sport mode (or whatever it's called on my 05 LGT). the tranny has 196k on it. is it time for a new tranny, or is there another diagnostic I can look in to? if I do need a new tranny, where's the best place to source one? I found one on ebay for $799. is that a fair price?

[MTBwrench]

welp, I was at the Dyno yesterday. engine passed the smoke test and diagnostics. got the car strapped down, dyno calibrated, and did one WOT 3rd gear pull. P0700 and another code about the cam position sensor. car will start, but wont drive more than a minute before it shuts itself off. then I have to wait some time before the car will start again. Prior to the P0700, the trans worked great in Drive, but was laggy and rough in the sport mode (or whatever it's called on my 05 LGT). the tranny has 196k on it. is it time for a new tranny, or is there another diagnostic I can look in to? if I do need a new tranny, where's the best place to source one? I found one on ebay for $799. is that a fair price?

 

Replace your cam sensor and take it from there. Engine should still run fine if there's a trans issue(unless that issue is with the converter). See my response in your thread.

[JazzAvi8r]

another Newb question:

 

are all 5EATs the same? basically, as I'm shopping around for trannys, I just want to know what will fit in my car. i have to assume that OBXT and FXT with the 5EAT are the exact same as the LGT (both wagon and Sedan), correct? I just want to make sure before I drop some cash on a new one.

 

thanks everyone for all your help.

[snow05gtRI]

I don't think the FXT has a 5EAT.

 

05-07 (I think 07) LGT or OBXT should work.

[JazzAvi8r]

"think" and "should" are not words that give me the warm fuzzy. can anyone confirm?

[snow05gtRI]

they added VDC in the 07's but I believe the VB and trans are the same.

 

In 2008-2009 they switched to a different VB at the very least which is more like the 4EAT. I'm not sure if the physical trans changed.

 

The OBXT has a different final drive than the LGT but I think that's done in the diff and not the trans itself.

 

I'm giving you some direction... the site has a search function.

[JazzAvi8r]

i didn't mean any animosity. i appreciate the insight. just figured someone might be able to rattle off the answer before i was able to find it on my own.