"Studdering" Fix Released

[mwiener2]

I've put another couple hundred miles on the car since i got the fix. Definatly seems like they reduced a little power on the real low end to make the surging go away. But it wasn't really usable power downthere anyways...so it just feels smoother. I also drove around today with a full load of people. It was real smooth. I still get a little stuttering here and there, but it's much more subtle and less frequent.

 

As far as the less power down low and it not being usable: I'm talking about idle to about 1800 rpm. There is definatly less power there now. 5EAT's.....sucks to be you. 5MT, you won't notice it at all when driving hard and when driving nromal, it just feels smooth.

[DKB_SATX]

Post-"fix" update:

 

I must say that there's a definite improvement, but it's still not perfect. My ECU was sent to New Jersey on Monday 25 July and got back to North Park Subaru on Friday 29 July. While the normally-aspirated 4EAT Outback was way nicer than some Malibu or Neon rental, I did miss that 82 hp! They didn't call me until about 6 on Friday evening, and I had an obedience class with the bull terrier who made me buy a wagon instead of a sedan, so I didn't get to pick the car up until Saturday morning.

 

So, I'm testing in the worst conditions... hot, humid, with AC. I can still feel some hesitation/surging at the usual worst points... 2500-3500 RPM in higher gears, which was particularly frustrating in the 60-75 range on the highway. Now it seems that the both the amplitude and frequence of the impulses seems to be significantly reduced. I haven't noticed any difference in total power, but I haven't done any focused testing, just spirited driving.

 

So, for what I paid (nothing) I'm pleased with the improvement but it's still definitely not perfect, and not really what I expect from a $30k car. I'm probably going to be able to use this to talk myself into buying an AccessPort though... we'll see!

 

DKB

[SBT]

Just got back from a 100 mile trip out into the mountains, temp ranges (at 6:30-8:00 PM) 78 F at the coast to 92 F in the mountains. Humidity - HIGH. As the ECU relearns, it has remained smooth. Initial mileage wasn't that great but on this loop I averaged about 23 mpg up to 7500 feet cruising at 80 on the freeway and about 65 mph overall, much under load.

 

There does seem to be some more noticeable wastegate action as though the WG was opening and closing rapidly but that was only if I accidently "lugged" the engine in higher gearing at lower RPM and then shifted down to regain power and acceleration.

 

On/off throttle, the engine was entirely smooth, running through the twisties in 2,3,4,5th gear. I could sense more than know that the IC was getting enough cool air but the power delivery was still smooth. I particularly added throttle several times under load in 5th gear at about 2500 rpm to see if it would cause a reaction but, again, the car just accelerated without any hesitation or stammering.

 

I'm optimistic at this point that SOA has dialed out at least 95% of any previous problems. Time will tell and I'll keep you all advised on the progress.

 

SBT

[mkalbarc]

Thanks again for the update, SBT!

I really would like to have this done, but my main problem is that I work a ton! Might be a few weeks until I can set something up with the dealer so I will still be looking forward to your updates.

Thanks!

[Skillz]

Just bought my 05 GT LTD 5EAT and guess what..... I also have the studder between 2500-3000. My salesman says it is could be bad gas so I will quickly run this tank dry. I haven't seen many posts about this from us 5EAT guys. I will be talking to the dealership tech department this week to see what they have to say.

[dark_rex]

Ummmm. I think you're confused. Typically when increasing boost, tuners will alter the fuel tables to add more fuel to specifically avoid a lean condition. A/F ratio and boost target tables can be controlled and manipulated independently from each other.

 

If you were silly enough to increase boost without also increasing fuel delivery, the engine would, in fact, run lean... At least for a few minutes before your pistons burn.

 

Look. you're totally misinterpreting me. I'm saying the legacy (like all turbo subarus) is programmed to run very rich in stock form. one of the reasons pro tuners are finding so much more power with a simple reflash is b/c they are, as you say, "independantly" controlling air and fuel. leaner mixes make more power. if the car is running 11.1 a/f, a tuner can increase boost "independantly" of the fuelling to achieve target a/f (14:1 or whatever) which inherently is a more efficeint, powerful mix.

 

"tuners are just increasing boost" doesn't make sense. pro tuners are adjusting timing, air and fuel all independantly to achieve target a/fs, as well as egt levels. "boost" alone doesn't mean squat.

 

as for the ECU compensating due to MAF readings, that's fine. but that's also exactly why you have a tuner reflash your ECU. changing the tables so the ECU reacts differenlty under certain conditions is precisely the reason you spend $600.

 

pistons don't "burn" unless you are running TOO lean, or detonating. they don't actually burn though. running too lean risks high egts, preignition and/or detonation which could lead to broken ring lands, crowns, pitting, burnt valves, etc. nothign actually "burns"

 

simply, if the legacy is in fact running pig rich from the factory, it would potentially explain why

1) tuners are getting so much more power with just a reflash, and

2) we are having surging/studder issues.

 

dR

[smkscrn]

does an aftermarket REFLASH, such as COBB's, void our manufacture warranty? Really interested in gaining some significant power, just by tuning the ECU. Not interested in "physical" mods....exhaust, etc.

 

joe

[mkalbarc]

Yes, it will VOID it. But from what I have heard, the accessport can put your ecu back to factory settings so they cannot tell it was ever messed with.

[smkscrn]

im assuming the "accessport" is a different brand or a device that comes with the new ECU to change maps, etc.....

 

joe

[ekuhockey18]

COBB makes the Accessport, but it does allow you to change ECU maps and reflash back to stock if/when you take it back to the dealer

[smkscrn]

so if you were to flash it back to "Stock", what is a way, if any, that they could detect an issue or "tampering" with the ECU??

 

any ideas how?

[SBT]

I think this was asked previously but cannot find the response... If the AP overwrites "maps" in the ECU, does it also pull out and store the ECU's stock map internal to itself in non-volitile memory? What happens if SOA reflashes the ECU and then you re-marry/apply your AP maps? When you go back to stock, do you go back to the original "stock" or to the now "SOA reflashed stock"?

 

I'm concerned that the AP has the old stock maps in it and if you were to set an SOA reflashed ECU back to stock, you'd overwrite it with the original pre-SOA reflash map.

 

Does any of this make sense?

 

SBT

[Erickson00]

Not another problem. Just that when you get your ECU reflashed, the security system, which is integrated into the ECU, no longer recognizes your remote fobs. So, just take them with you when get your ECU reflashed and the dealer will reprogram the system for you. Or, you can do it yourself, following the instructions in the manual.

 

The dealer asked me to bring my extra fob when I came to pick up the car, so they could program both at the same time. Thought it was cool of them to think of that and call me.

 

Incidently, went for an 80 mile run up the coast for dinner tonight and in and out of traffic the car was smoooooth. My wife even commented on how smooth it felt and if she notices something like that, it is definiitely something out of the ordinary. I just couldn't get over how much oomph the car had, even at lower rpms in 5th. Nary a hiccup the whole drive

 

SBT

 

I am happy for you. I wonder why my car came back WORSE when they received it back from New Jersey. I barely experienced the problem when I brought it in, and the service manager said "it wanted to fall on its face" when he test drove it after the ECU reflash. They are ordering me a brand new ECU. Should be the "latest" one available, so maybe I'll get to experience what you're experiencing. I am excited!

[SBT]

Thanks, SB!!

btw, what was the build-date of your car? I haven't had much bucking, but if it can make mine feel even teh faster.. :-)

Actually, maybe everyone who's qualified for the fix could post their build-time? We bought our Wagon in January '05, haven't checked build-time yet.. Just wondering if we qualify or not..

HV

 

Just saw your question....sorry my bad. My wagon was built in 12/04 and I took delivery in 01/05.

 

SBT

[starlabs]

Makes sense to me.. but let me rephrase your question in software terms - maybe that'll be easier:

 

Let's say a stock car comes with ECU version 1.0.

Accessport comes with a nice version 2.0.

 

You flash ecu to AP 2.0, the accessport saves the orig ecu version 1.0 to it's memory (if it does that)

 

You're about to take the car back to the dealer, you flash it back to ecu version 1.0. That version still remains in the AP as well (?)

 

Dealer takes car, flashes to a new factory 1.1 version.

 

You take the car back, now you flash it to AP 2.0. The question then becomes, which version will get saved - factory ecu 1.0 or 1.1?

[Blaze]

I have seen discussions on this forum in other threads about stock maps flashing with the AccessPort. I think there was talk of your original software map from Subaru being watermarked somehow so that it reflects a serial number of your ECU. While the AccessPort can reflash back to a stock map....I don't think it can backup YOUR actual stock map so that you can reflash at a later date to exactly the way it was before. There had been talk that this capability would come out...but I'm not sure when or if it ever will. I was hoping that it would before I get my AP.

[Blaze]

Makes sense to me.. but let me rephrase your question in software terms - maybe that'll be easier:

 

Let's say a stock car comes with ECU version 1.0.

Accessport comes with a nice version 2.0.

 

You flash ecu to AP 2.0, the accessport saves the orig ecu version 1.0 to it's memory (if it does that)

 

You're about to take the car back to the dealer, you flash it back to ecu version 1.0. That version still remains in the AP as well (?)

 

Dealer takes car, flashes to a new factory 1.1 version.

 

You take the car back, now you flash it to AP 2.0. The question then becomes, which version will get saved - factory ecu 1.0 or 1.1?

 

 

You would need to unmarry the AccessPort from your current ECU....or you might not be able to use the AccessPort when you got your LGT back from the shop without jumping through hoops with Cobb Tuning. I'm pretty sure the AP doesn't "backup" your original stock map....unless they finally released a new AP version that has this capability. Rather, you use a stock map that Cobb has available for you to use.

[eles1]

pistons don't "burn" unless you are running TOO lean, or detonating. they don't actually burn though. running too lean risks high egts, preignition and/or detonation which could lead to broken ring lands, crowns, pitting, burnt valves, etc. nothign actually "burns"

 

Not to get in an argument, but you're wrong. Aluminum most certainly will undergo rapid oxidation (combustion) at high temperatures in an oxygen-rich atmosphere. Steel will also burn under those conditions - but it takes slightly higher temps. Probably not the only failure mode of a poorly tuned FI engine, but a very possible one. I've seen it first-hand...

 

In most cases, the A/F ratios after tuning are very nearly the same as before tuning. The idea that aftermarket tuners are increasing this, or any other, engine's output by leaning out the A/F ratio is simply false (this was your original contention). The increase in power comes from increased boost and the increased fuel delivery to support it. Period. They may tweak or slightly adjust the A/F, but the power to be gained there is minimal.

 

"independantly" of the fuelling to achieve target a/f (14:1 or whatever) which inherently is a more efficeint, powerful mix.

 

14:1 is WAY too lean for an FI engine at WOT. Cobb's tuning is more in the 11:1 range - probably not too far off of Subaru's stock A/F values, maybe even a bit richer. If you don't believe me, check Cobb's website and see for yourself.

[SBT]

Makes sense to me.. but let me rephrase your question in software terms - maybe that'll be easier:

 

Let's say a stock car comes with ECU version 1.0.

Accessport comes with a nice version 2.0.

 

You flash ecu to AP 2.0, the accessport saves the orig ecu version 1.0 to it's memory (if it does that)

 

You're about to take the car back to the dealer, you flash it back to ecu version 1.0. That version still remains in the AP as well (?)

 

Dealer takes car, flashes to a new factory 1.1 version.

 

You take the car back, now you flash it to AP 2.0. The question then becomes, which version will get saved - factory ecu 1.0 or 1.1?

 

starlabs - that's my question exactly. Now that you've said it so much more articulately, anyone have any ideas on which "version" would actually get retained/saved as the "stock" map?

 

Blaze - that functionality would be perfect if it were part of the package.

 

SBT

[smkscrn]

Well, Im just hoping that when I take my LGT in on Thursday to the dealer and talk about the stock ECU issue, that when I get it back, if it qualifies for a reflash, it will be silky, smooth, and powerful like a 30grand turbocharged boxer engine should...and I wont even have to worry about an aftermarket ECU.......unless I get greedy and want a lil more juice...lol. (either way probably after the warranty anyways)

 

joe

[dark_rex]

Aluminum most certainly will undergo rapid oxidation (combustion) at high temperatures in an oxygen-rich atmosphere. Steel will also burn under those conditions - but it takes slightly higher temps. Probably not the only failure mode of a poorly tuned FI engine, but a very possible one. I've seen it first-hand...

 

aluminum only starts to soften at 1600 degrees. it would have to be significantly hotter for it to actually combust. i'm sorry, "at high temperatures" may be right, but very unlikey in your subaru. you will certainly kill the engine long before aluminum angine parts actually burn. as i said, when they heat up, they can become more brittle and pit, chip, or crack or bend/warp. those are the real risks.

 

In most cases, the A/F ratios after tuning are very nearly the same as before tuning. The idea that aftermarket tuners are increasing this, or any other, engine's output by leaning out the A/F ratio is simply false (this was your original contention). The increase in power comes from increased boost and the increased fuel delivery to support it. Period. They may tweak or slightly adjust the A/F, but the power to be gained there is minimal.

 

SIMPLY FALSE? Maybe you should check all the links i've posted below proving you wrong. period! lol

 

 

Cobb's tuning is more in the 11:1 range - probably not too far off of Subaru's stock A/F values, maybe even a bit richer. If you don't believe me, check Cobb's website and see for yourself.

 

Seriously, are you just making this up as you go along? richer?

 

 

stock dyno run.

9.5:1 AFR from 3500rpms to redline.

http://www.legacygt.com/forums/attachment.php?attachmentid=8578

 

 

final protuned dyno run

13:1 AFR falling to 11.5:1 at redline.

http://www.legacygt.com/forums/showthread.php?t=13324&highlight=dyno+charts

 

Stage I AFRs

about 2 points leaner again.

http://www.legacygt.com/forums/showthread.php?t=13405&highlight=dyno+charts

 

Dan at Mach IV

with his maps leaning out 2 pts to 11:1

http://www.legacygt.com/forums/showthread.php?t=8604&page=3&pp=10&highlight=dyno+chart+graph

 

would you call going from 9:1 to 11:1 richer? haha.

 

back on topic, as i said, it looks like the people with aftermarket maps are not having studdering problems, so it seems likely the rich stock condition is being remedied with the aftermarket ECUs, and fixing the studder.

 

dR

[Peale]

I've had the fix for about 4 days now, and it is about 50-70% better for me.

I can still feel it in 3rd and some in 4th gear but less prominent. Haven't noticed any change in power.

 

/t

[mkalbarc]

Thanks for the update, Peale

Let us know if you notice any more changes.

 

Thanks

[ROBMAN]

Sorry if I'm missing something here.....but seems many of you who have had "the fix" had their ECU's shipped out by your dealer for a reflash?

 

My dealer actually replaced my ECU with a brand new one from SOA. Different part number as well. They had the new ECU drop shipped, and only kept my car overnight.

 

What seems to be the dealer preferred method, reflash or replace????

 

By the way, my GT LMT 5spd......night and day with the new ECU. Freak'n fan problem gone.....zero studdering.

[eles1]

aluminum only starts to soften at 1600 degrees. it would have to be significantly hotter for it to actually combust. i'm sorry, "at high temperatures" may be right, but very unlikey in your subaru. you will certainly kill the engine long before aluminum angine parts actually burn. as i said, when they heat up, they can become more brittle and pit, chip, or crack.

 

 

 

SIMPLY FALSE? Maybe you should check all the links i've posted below proving you wrong. period! lol

 

 

 

 

Seriously, are you just making this up as you go along? richer?

 

 

stock dyno run.

9.5:1 AFR from 3500rpms to redline.

http://www.legacygt.com/forums/attachment.php?attachmentid=8578

 

 

final protuned dyno run

13:1 AFR falling to 11.5:1 at redline.

http://www.legacygt.com/forums/showthread.php?t=13324&highlight=dyno+charts

 

Stage I AFRs

about 2 points leaner again.

http://www.legacygt.com/forums/showthread.php?t=13405&highlight=dyno+charts

 

Dan at Mach IV

with his maps leaning out 2 pts to 11:1

http://www.legacygt.com/forums/showthread.php?t=8604&page=3&pp=10&highlight=dyno+chart+graph

 

would you call going from 9:1 to 11:1 richer? haha.

 

back on topic, as i said, it looks like the people with aftermarket maps are not having studdering problems, so it seems likely the rich stock condition is being remedied with the aftermarket ECUs, and fixing the studder.

 

dR

 

 

Wow. You're very persistent, even though your maturity level is rapidly declining.

 

Aluminum will burn in an oxygen rich atmosphere at temps much lower than its normal ignition point, and temps WAAYYY above 1600°F are very common within the combustion chamber itself. As I said, I've seen it first-hand in both nitrous and FI engines. Perhaps I was dreaming...

 

As far as A/F ratios go, I've datalogged my Subaru when stock and most of the time the A/F ratio stayed right between 11:1 and 12:1, very close to what it runs @ stage 1. I guess I'm dreaming that as well . Have you ever actually datalogged your car to see what it's doing??

 

Cobb's stage 1 A/F ratios are between 10.8:1 and 11.2:1, which are comparable to what I've been seeing when I datalog

http://cobbtuning.com/legacy/images/ap-lgt-stage1.gif

Amazing how they can get the extra power without leaning the A/F ratios. In any event, it's not near the 14.1:1 that you suggested earlier. That ratio is getting close to dangerous for an NA car.

 

Regarding the stock dyno graph you've posted, I don't see the A/F ratio dropping below 10:1 at any point. Am I missing something? There's certainly nothing as low as 9.5:1 on that graph!! It's only down at 10:1 for a couple hundred rpm, at most. The horizontal dotted line it's hovering near for most of the range is 10.5:1, as I read it...

 

One last thing. I have Cobb Stage 1/91 (v1.10 maps) tuning in my car right now, and I can tell you that it most certainly does not completely address the stuttering issue. Trey himself has posted that the stutter is a complex issue that is more closely related to open/closed loop transitions than anything else. Now tell me I'm imagining that as well.