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Old 11-24-2004, 03:53 PM   #1
adg016
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Default WRX Detonation Cause FOUND! (Datalogs Included)

All,

Bill Knose (Lead Tuner and Co-owner of I-Speed USA) and I spent significant amounts of time datalogging my car both pre- and post-ECU-reset this week. The data we found is very revealing, and proves that this is not simply a CA only issue. It is a fueling issue that is in need of attention across the board.

To those of you who wish to skip straight to the logs before reading on, they can be found at http://gallery.aboutgardner.com/gallery/album05. There is a pre-ECU reset log and a post-log. Click each once, and then click again to enlarge to readable scale.

Bill's comments and interpretation of the logs are included below, but first here are some salient points:

1. A/F ratios under FULL throttle and FULL boost are maintaining at 14.7:1 all the way until around 5,300 rpm.
2. Injector duty cycles are only around 58% during that time before FINALLY shifting over to in excess of 90%.
3. EGT readings are in excess of 1,660 degrees F.
4. Knock correction is occuring after detonation, but knock is continuing to occur because pulling timing doesn't solve the incorrect fueling issue.

The aforementioned four points represent a pretty serious issue, and explain the persistent detonation. Subaru, are you listening?

Now, onto Bill's comments...
---------------------------------

After taking a quick look at the data logs (before ECU reset) we took on November 22, 2004, it became very clear what the problem was. In the data logs you will notice under full throttle there is not enough fuel flowing to the engine. Then, in a single step, the injector duty cycle jumps from 58.55% to 88.88%, which takes only a few milliseconds. Before the injectors bump up the duty cycle, notice the A/F ratios under full throttle and full boost are 14.57:1 which is far too lean for full throttle and boost levels of 12.2 PSI. To reinforce the point, the Exhaust Gas Temperatures are at 1,625 degrees Fahrenheit and still rising. If this EGT probe was right below the heads where most install them, the temps would be above 1700 degrees Fahrenheit!

Now maybe this was just a fluke, so we did an ECU reset and data logged all the relevant information again. Once again the injector duty cycle jumps from 59% to 91.74% in a few milliseconds. Also notice that the A/F ratios before the injectors switch duty cycles are still at 14.68:1, again far too lean for full throttle and boost levels of 12 PSI. The Exhaust Gas Temperatures here are at 1,553 degrees F and rising very fast to above 1,600 degrees F.

The thought that the timing was too high and causing detonation is incorrect. The knock correction shows that timing is being pulled, though this will not help the fact that the car is running too lean. As the data shows, the car is unequivocally running far too lean; no matter how much timing you pull out, the car will detonate with these boost levels and lean conditions. Turbo cars are meant to run much richer than stoichiometric, and even the model year 2002 WRX runs A/F ratios as rich as 10:1 from the factory. Just to push the point further, even naturally aspirated cars run safe levels of 13.5:1 or richer.

My thoughts are that the delay period between closed loop and open loop fueling are taking too long and need to be shortened. There also might be a possible error in the code of the ECU causing the fueling to run incorrectly for a period of time. This seems to be about 1 to 2 seconds while on full throttle. This has been a common problem with many 2004 Subaru WRXs that are being driven today.

Cheers,

Bill Knose
Lead Tuner
I-Speed USA

And again, the link to the datalogs to those of you that did not skip ahead:

http://gallery.aboutgardner.com/gallery/album05.
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Old 11-24-2004, 04:03 PM   #2
supermarkus
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I didn't pay close attention to this issue since I had an '02 WRX, but I thought this was already addressed by some tuning houses on the '04 WRX. I'm sure the closed loop/open loop transition problem isn't breaking news. Anyway, I'm glad you know the cause of your problem, good luck with the solution.
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Old 11-24-2004, 04:03 PM   #3
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check out this thread:

http://forums.nasioc.com/forums/show...ighlight=surge

looks like it is an 05 problem too:

http://forums.nasioc.com/forums/show...pen+transition

edit: a little more info for your issue:

http://forums.nasioc.com/forums/show...pen+transition

bottom line, what you are experiencing is normal, it is the way the processors have been redesigned to work with euro fuel regulations, get an accessport.

this is the exact reason you don't want to put any uppipes or downpipes on the '04s till after you get some engine management, things just go too fast, and then go boom.

Last edited by samagon; 11-24-2004 at 04:08 PM.
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Old 11-24-2004, 04:20 PM   #4
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Quote:
Originally Posted by samagon
bottom line, what you are experiencing is normal, it is the way the processors have been redesigned to work with euro fuel regulations, get an accessport.

this is the exact reason you don't want to put any uppipes or downpipes on the '04s till after you get some engine management, things just go too fast, and then go boom.
Thanks for the info, but we're not working with euro fuel regs here, and a car owner shouldn't have to pay a tuner to get their car running correct A/F ratios in the first place.
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Old 11-24-2004, 04:31 PM   #5
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Default well...

i think in the former thread someone mentioned about having similar probs, switched ecu's, and the prob totally went away....

so that would make sense... this problem is not engine driven, its ecu driven... can't subaru 'reflash' it to fix it???
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Old 11-24-2004, 04:33 PM   #6
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Quote:
Originally Posted by RexRonald
i think in the former thread someone mentioned about having similar probs, switched ecu's, and the prob totally went away....

so that would make sense... this problem is not engine driven, its ecu driven... can't subaru 'reflash' it to fix it???
You got it, man, but this data was collected from an ECU that Subaru DID reflash as a solution to high-rpm detonation, and this is STILL what we're left with.
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Old 11-24-2004, 04:35 PM   #7
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This is all very interesting. You definitely put forward a lot of effort in gathering all of this data. I've done some logging in my car (04, turboback) and definitely do not see this. I assume you are logging EGTs with the uppipe sensor? If that's the case, I don't see EGTS much above 1500 right now.

I'll try to get some more data this weekend. If you'd like to compare logs, please let me know.

Thanks
Mike
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Old 11-24-2004, 04:49 PM   #8
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Quote:
Originally Posted by crazymikie
This is all very interesting. You definitely put forward a lot of effort in gathering all of this data. I've done some logging in my car (04, turboback) and definitely do not see this. I assume you are logging EGTs with the uppipe sensor? If that's the case, I don't see EGTS much above 1500 right now.

I'll try to get some more data this weekend. If you'd like to compare logs, please let me know.

Thanks
Mike
Mike,

Let's do that. I know Bill at I-Speed would be very interested as well. And, yes, it's the uppipe sensor that the readings are coming off of. 1,500 degrees F sounds MUCH better to me.
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Old 11-24-2004, 05:01 PM   #9
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so are you able to correct this with an ecutek reflash so this lag in fueling will not occur?
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Old 11-24-2004, 05:06 PM   #10
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Quote:
Originally Posted by senortighto
so are you able to correct this with an ecutek reflash so this lag in fueling will not occur?
Yes, from what I understand, Bill at I-Speed can correct this. They do use Ecutek. If you're curious, their website is http://www.i-speed.us/home/.
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Old 11-24-2004, 05:28 PM   #11
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You're wasting your time! Uncle Scotty sez you should buy a different car! ROFLWAFLZ

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Old 11-24-2004, 05:56 PM   #12
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Good information and thanks for keeping everyone in the loop.

I urge anyone running a stock WRX to try to gain some data logs using the same method adg016 used, logs before ECU reset and logs after ECU reset. If there are other cars experiencing the same issues than obviously the cause of the det and high EGT's will have been isolated. Although Bill does state this is a common problem among '04 WRX's, and I know he has seen dozens of these models doing tuning for customers.

Now I just hope that Subaru will do the right thing here and address the problem instead of attempting to sweep it under the perverbial rug.
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Old 11-24-2004, 06:33 PM   #13
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Quote:
Originally Posted by fogdor
You're wasting your time! Uncle Scotty sez you should buy a different car! ROFLWAFLZ


....fix the problem, and don't cry and whine here about it.....the issue isn't the car, really, it's the numerous posts about it......

Many possible solutions have been offered over the last few months, none seemed to suite the owner and I (and others) am tired of hearing about it, especially because THERE ARE SOLUTIONS AVAILABLE TO THIS KNOWNISSUE.

This is NOT an engine issue at all, like I have said before....it IS an engine management issue and should be dealt with in the appropriate forum....and that will be the warranty/SOA forum shortly, I hope the MODs will put it where it belongs.
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Old 11-24-2004, 07:22 PM   #14
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subscribe
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Old 11-24-2004, 07:35 PM   #15
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Quote:
Originally Posted by Uncle Scotty
....fix the problem, and don't cry and whine here about it.....the issue isn't the car, really, it's the numerous posts about it......

Many possible solutions have been offered over the last few months, none seemed to suite the owner and I (and others) am tired of hearing about it, especially because THERE ARE SOLUTIONS AVAILABLE TO THIS KNOWNISSUE.

This is NOT an engine issue at all, like I have said before....it IS an engine management issue and should be dealt with in the appropriate forum....and that will be the warranty/SOA forum shortly, I hope the MODs will put it where it belongs.
Uncle Scotty... We have all the reason in the world to cry and moan! I have a stock 2004 WRX that detonates like a muther-f. I want it fixed! By Subaru! not by me forking out my own money for an aftermarket ecu, re-flash or water injection... If your tired of hearing about this ****, then dont read it, dont post bagging on us. Its people like you why I dont post on this forum...

Dan, thanks again! Lets get this to Subaru and see what they say!
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Old 11-24-2004, 07:52 PM   #16
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This is why we released the open loop fuelling software that has been around for about a year or so now. I think you guys should check out some of big adventures posts on the subject from last fall.
http://forums.nasioc.com/forums/show...highlight=utec
http://forums.nasioc.com/forums/show...highlight=utec
http://forums.nasioc.com/forums/show...highlight=utec

You can also see the firmware update thread where we released the open loop fueling software fix http://forums.nasioc.com/forums/show...highlight=utec in March of this year. I’d say this is a “known” issue.

I am not surprised in the least that a completely stock WRX will knock before it transitions to open loop fuelling.
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Old 11-24-2004, 07:57 PM   #17
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Thats nice and all... but I AM NOT GOING TO FORK OUT ANY MONEY TO FIX A PROBLEM THAT A STOCK CAR SHOULDNT HAVE! Thats subaru's problem, not mine! So if you want to give me a utec and tune my car for FREE then thats cool, otherwise.... i dont care... also thoes threads I looked at you posted are not pertaining to STOCK cars
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Old 11-24-2004, 08:03 PM   #18
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Quote:
Originally Posted by xodus31
Thats nice and all... but I AM NOT GOING TO FORK OUT ANY MONEY TO FIX A PROBLEM THAT A STOCK CAR SHOULDNT HAVE! Thats subaru's problem, not mine! So if you want to give me a utec and tune my car for FREE then thats cool, otherwise.... i dont care... also thoes threads I looked at you posted are not pertaining to STOCK cars
Here, here!
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Old 11-24-2004, 09:07 PM   #19
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Just to jump in My 04 has the same open loop delay. I had her tuned last week and we got it better with the unichip, but dynocomp says w/ecutek he can change the delay, etc. It was scary watching the car hold 14.7/1 a/f till 5000, usually the third pull it would switch and power would come up as she ritchened. I agree, Subaru should fix their ECU from the factory.
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Old 11-24-2004, 09:08 PM   #20
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Would an '03 or '02 Ecu drop right in or are there more outside variables such as sensor voltages,etc to deal with?
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Old 11-24-2004, 10:19 PM   #21
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tagged.
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Old 11-25-2004, 01:45 AM   #22
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Quote:
Originally Posted by fastrob691
Would an '03 or '02 Ecu drop right in or are there more outside variables such as sensor voltages,etc to deal with?
I don't believe those ECUs will work in our cars. Anyone wanna confirm?
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Old 11-25-2004, 02:27 AM   #23
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all I can say is that a stock ECU running 14.7 is retarded....

Just shows the amount of lazinezz and complacency SOA has gone with the WRX simply because they know it will produce numbers and they don't give a **** because they know half the buyers will tune them,... regarless it should run right from the factory and this kind of product being mass produced and set upon unsuspecting buyers in an injustice to the whole industry and IMO right on par with Mitsu extorting money from customers for voided warranty claims when all a knowing customer would have to do is bring up the Magnussen Moss Act...

SOA is conducting ****ty business compared to the company we all loved 3 and 4 years ago. This ... and all but dumping Prodrive USA for ESX. Somebody at SOA needs to wake up because this is pathetic.
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Old 11-25-2004, 10:55 AM   #24
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I did a few pulls this morning. Unfortunately, there's not a lot of road to work with, so I only got up to about 80mph in 3rd, but here's what I found.

It usually takes 2-3 seconds for AFR to go from stroich to rich after I floor it. This usually translates to running lean with full boost up to 5200rpm or so. I didn't see any knock at all and my knock correction was fine, too.

I also looked at some logs from my friends Stg2 car (also '04). He's got an AccessECU. His car starts running rich by 4400rpm or so, but still the same 2 second delay exists between full throttle and running rich. I have the logs on the laptop, but only one network cable and now floppy disk drive.

I'll email them to myself later so I can post them up.

Mike
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Old 11-25-2004, 11:05 AM   #25
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Have your buddy re-flash with the latest '04 AP stage 2 base map. Cobb had a fix for this as well but you have to reflash the basemap. Changing to the latest real time maps won't fix the issue.
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