Mega Users seabass07 Posted August 23, 2012 Mega Users Share Posted August 23, 2012 There are very few differences between the different ecu versions. It's very possible that it only overwrote the changed parts of the rom. IIRC, the only difference that I noticed (that could be seen with romraider) was per cylinder timing adjustments. I suspect that most of the changes between versions are in the logic, not the maps. Maybe it left your stage 1 maps in tact. The current state of your ecu should be easy to figure out. If your current version is A2WC522N and you are hitting 15-16psi, then you are on the updated rom and stage 1 tune. Link to comment Share on other sites More sharing options...
ssbtech Posted August 23, 2012 Author Share Posted August 23, 2012 So is the ROM different from the map or are the maps part of the ROM? ie: If I divorce the AP, will it go back to the A2WC510N or will it just be the tune that reverts back to stock? If the dealer ROM corrected performance issues, then I'm guessing that there must be some overlap. Link to comment Share on other sites More sharing options...
fahr_side Posted August 24, 2012 Share Posted August 24, 2012 Are there really no stickies that carry these very basic concepts? Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
ssbtech Posted August 24, 2012 Author Share Posted August 24, 2012 Are there really no stickies that carry these very basic concepts? Probably, but they're full of irrelevant posts too. Link to comment Share on other sites More sharing options...
fahr_side Posted August 24, 2012 Share Posted August 24, 2012 Mmmkay. I'll try to explain this as best I can, but bear in mind I approach all these from a tuner's POV not a hacker's! A ROM as usually discussed here is an image (in binary or hexadecimal form) of the code and parameters in Read-Only Memory in the ECU. It contains the ECU logic and preset parameters, like boost targets and various compensations. These parameters are be displayed in table format by various editor software applications. These tables and even the complete ROM are often referred to as maps, and the process of tuning often called mapping or re-mapping. So, in general popular use, a ROM is a map, a map is made up of tables, and the data in those tables defines the tune. A complete ROM will also contain the immobilizer codes and other stuff but in Opensource reading and flashing these areas are not read or written to in normal operations. This is usually only done when rescuing a bricked ECU. Think of that being like a low-level reformat on a HDD. When flashing with OS tools the ROM loaded in the PC software (like Ecuflash) is compared to the one in the ECU and only the areas that are different are written to the ECU. I believe Subaru's own SSM tools do the same. So, if Cobb has for example changed the values in tables like boost and fuel targets, when the SSM device flashes a new ROM (like the update you mention), the values Cobb changed will be seen to be different and then overwritten with the new stock values, removing the Cobb 'tune'. Note also that the very act of reading the ROM off the ECU erases all the learned values stored in RAM, just like a reset does. Does that make sense now? Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
ssbtech Posted August 24, 2012 Author Share Posted August 24, 2012 Thanks, that does clarify it. Sort of. I understand that there are various tables for things like boost, fuel, timing, etc... You're saying that the SSM only replaces what it sees as being different. Now is that complete tables or is it as specific as specific cells in those tables? I guess what I'm concerned with is if I have a COBB tune still or a combination of COBB and Subaru tables on there. Because that makes it sound like things could go horribly wrong if there's a hybrid of COBB and Subaru tables there. Link to comment Share on other sites More sharing options...
Mega Users seabass07 Posted August 24, 2012 Mega Users Share Posted August 24, 2012 I doubt that is the case. There is no reason for it to search for differences and then change them to stock. What it likely does is update only the parts of the rom that are changed by the update. If all they are doing is fixing a logic error here and there, there is no need to rewrite the entire thing. Either it will overwrite everything or it will only replace the small bits affected by the update. There is no reason to search out differences. Since the maps that are changed in a stage 1 tune are identical between the two rom versions, most likely they were untouched by the update. Once again, the easiest way to test this out is to log manifold relative pressure. If you are hitting 15-16psi at WOT, you still have the stage 1 tune. Link to comment Share on other sites More sharing options...
fahr_side Posted August 24, 2012 Share Posted August 24, 2012 When you flash a ROM with Ecuflash there are reports from about 15 blocks on whether or not there are differences between the loaded map and the one on the ECU. This is logged for you see. Then the write goes ahead. IME the time it takes to write the new ROM image to the ECU seems to vary with how many of those areas or blocks have differences. For example if I flash a stg2 map over a stock one, it takes longer than if I have just revised one table. I think the blocks are just ranges of memory addresses and don't necessarily match to specific tables. It seems to me the whole block is written if even one byte of data is different. Therefore it's not possible to end up with a ROM image that's half of this and half of that unless you edit it that way on the PC. Any data blocks that are different from those in the stock ROM will be over-written by the new updated stock ROM. Once the blocks are written, Ecuflash checks that the images are now identical before reporting the write was successful. Again this activity is logged. Does the SSM tool do the process in the same way? I don't know. Does the AP follow suit? I don't know. Does the AP automatically restore the stage map when it's reconnected or re-married to the ECU? I don't know. Obligatory '[URL="http://legacygt.com/forums/showthread.php/2008-gh8-238668.html?t=238668"]build thread[/URL]' Increased capacity to 2.7 liters, still turbo, but no longer need spark plugs. Link to comment Share on other sites More sharing options...
ssbtech Posted August 24, 2012 Author Share Posted August 24, 2012 I was going to log today, but my laptop's battery seems to have a wonky connection and the thing kept shutting off. (That gives me the warm and fuzzies for flashing...) Link to comment Share on other sites More sharing options...
ssbtech Posted August 30, 2012 Author Share Posted August 30, 2012 Log time! Looks like the flash from the dealer removed some of the AP maps. Will "returning to stock" with the AP cause any problems? I know the APV1 doesn't back up the original map but instead restores a "default" stock map loaded onto the AP at the factory. I'm totally confused how the car can run with part of a Subaru map and part of a COBB map. The AP still reads "Stage 1 91" map when I use it to display the current map. Today's log CSV.csv Link to comment Share on other sites More sharing options...
Mega Users seabass07 Posted August 30, 2012 Mega Users Share Posted August 30, 2012 When you flash a ROM with Ecuflash there are reports from about 15 blocks on whether or not there are differences between the loaded map and the one on the ECU. This is logged for you see. Then the write goes ahead. IME the time it takes to write the new ROM image to the ECU seems to vary with how many of those areas or blocks have differences. For example if I flash a stg2 map over a stock one, it takes longer than if I have just revised one table. I think the blocks are just ranges of memory addresses and don't necessarily match to specific tables. It seems to me the whole block is written if even one byte of data is different. Therefore it's not possible to end up with a ROM image that's half of this and half of that unless you edit it that way on the PC. Any data blocks that are different from those in the stock ROM will be over-written by the new updated stock ROM. Once the blocks are written, Ecuflash checks that the images are now identical before reporting the write was successful. Again this activity is logged. Does the SSM tool do the process in the same way? I don't know. Does the AP follow suit? I don't know. Does the AP automatically restore the stage map when it's reconnected or re-married to the ECU? I don't know. I hope it's obvious that I'm only speculating...but to clarify what I meant in the previous post: Ecuflash has to deal with us constantly changing random bits of info then reflashing while SSM has set in stone changes over the previous version. So there is no need for it to go through that process. Link to comment Share on other sites More sharing options...
Mega Users seabass07 Posted August 30, 2012 Mega Users Share Posted August 30, 2012 Log time! Looks like the flash from the dealer removed some of the AP maps. Will "returning to stock" with the AP cause any problems? I know the APV1 doesn't back up the original map but instead restores a "default" stock map loaded onto the AP at the factory. I'm totally confused how the car can run with part of a Subaru map and part of a COBB map. The AP still reads "Stage 1 91" map when I use it to display the current map. It seems like you should be able to revert to a stock map and then reflash the stage 1 with the AP. That should restore the full cobb stg1 tune on the new ecu version. Link to comment Share on other sites More sharing options...
ssbtech Posted August 30, 2012 Author Share Posted August 30, 2012 But restoring the COBB stage 1 (which I'm not even sure I want now) over top of the new ECU version will revert the ECU version back to the old one, right? I'm completely lost now. I don't understand the difference between "ECU version" and tuning maps. If the ECU ROM update corrects performance issues, then aren't ECU ROMs and tuning maps one and the same? Link to comment Share on other sites More sharing options...
ssbtech Posted August 30, 2012 Author Share Posted August 30, 2012 The reason I'm worried about reverting to stock with the AP is that I know the AP won't install on more than one ECU. Since it "thinks" the ECU still has the COBB tune (which it clearly doesn't) I don't want it to start writing and for some unknown reason stop and screw up. So far COBB hasn't replied to my emails and I have a feeling I'm swimming in uncharted water here. Surely there aren't too many people who have had their ECU partially updated by the dealer over top of a COBB tune and then removed what was left of the COBB tune. I can't take the risk bricking my ECU. Link to comment Share on other sites More sharing options...
ssbtech Posted August 31, 2012 Author Share Posted August 31, 2012 Well I got a reply from COBB. The AccessPORT is only showing the Stage 1 map as being the current map because it's the last map the AP flashed, not necessarily what's on the ECU. So I'm assuming at this point it is the full set of tuning maps that's been flashed by the dealer, not just the bits that have been changed by the AP (which is likely most/all of it anyway). Further adding insult to injury, COBB no longer has a way to reset the old AccessPORTs. Subaru keeps all the sheet metal dies back to 1990 but COBB can't keep a computer hanging around in the attic somewhere. Ok then. So I have a $600 brick in the back of my car and an engine that still shows -4FBKC on a factory map. (The log is attached a few posts up if aonyone missed it. Looks even more weird than the COBB log). Link to comment Share on other sites More sharing options...
Mega Users seabass07 Posted August 31, 2012 Mega Users Share Posted August 31, 2012 And in that log, you weren't close to hitting your stock boost targets. Link to comment Share on other sites More sharing options...
ssbtech Posted August 31, 2012 Author Share Posted August 31, 2012 I know. It was holding more than that in the previous logs so I'm not sure why it can't hit the target (which is lower than the COBB tune) now. Link to comment Share on other sites More sharing options...
ssbtech Posted August 31, 2012 Author Share Posted August 31, 2012 Now that my AP is no good, I wonder if it's worth getting the AP V2? $595 minus $200 COBB will give me for a trade in of the old unit. I don't know why it's worth anything on trade if it's essentially a lump of coal. Link to comment Share on other sites More sharing options...
ssbtech Posted September 1, 2012 Author Share Posted September 1, 2012 Looking at those logs, am I really supposed to be hitting 8.62 PSI of boost by 2110 RPM? If so, it looks like I'm missing out on a fair bit of performance if it's only hitting 3.2 psi... Link to comment Share on other sites More sharing options...
iNVAR Posted September 1, 2012 Share Posted September 1, 2012 No, the stock map sets a pretty high target. People have different tuning strategies. I know that Infamous has some pretty high targets on his maps too, but hey, everyone's strategy's a bit different and what may work for him may not work for my own tuning/tweaking strategy. I use significantly lower targets which may leave some torque on the table in higher gears, but it makes for a smoother ride and much finer and more consistent boost control. The stock tune has high targets because your stock map has a flag in it to force WGDC to that cap you see of 30.2 during a region. This stabilizes your boost, but effectively slows spool a lot. This is one of the things "fixed" by a stage 1 tune. Have you checked for boost leaks and other causes yet like a few people suggested 4 or 5 pages back? Link to comment Share on other sites More sharing options...
ssbtech Posted September 1, 2012 Author Share Posted September 1, 2012 So if the targets are significantly higher than what's achievable, how do I know when it really is actually underboosting? At what point is it supposed to hit peak boost? No, I haven't done any checks for leaks, etc.. I'm waiting for my next oil change and will have the dealer do a compression test as well as intake/boost leak test at that time. I'll also have him swap the coils around due to the recent misfire CEL. Link to comment Share on other sites More sharing options...
iNVAR Posted September 1, 2012 Share Posted September 1, 2012 Off the top of my head, you should be hitting peak at around 3000, maybe 3200 because it's stock. Check for those problems, and also back off on doing the pulls. 4* of timing being pulled is a significant knock at WOT... until you can determine that's false knock, I wouldn't want to keep subjecting your engine to that. Link to comment Share on other sites More sharing options...
ssbtech Posted September 1, 2012 Author Share Posted September 1, 2012 Thanks. I'm still betting on false knock. Remember when it was -8 FBKC? That dropped to -4 when I replaced the pop-screw things holding the engine cover on (they were breaking apart and the cover rattled a bit). As a side note, I'm surprised the CEL doesn't come on for that much knock correction. I can't imagine people who aren't all that car savvy plugging in AP cables and logging Link to comment Share on other sites More sharing options...
ripemeat Posted September 1, 2012 Share Posted September 1, 2012 some people buy a knock light just as a separate measure of monitoring besides the CEL Link to comment Share on other sites More sharing options...
ssbtech Posted September 2, 2012 Author Share Posted September 2, 2012 I have one more question to annoy you with. As boost starts to build slowly in 4th gear, I notice a jerkiness in the power delivery, almost like the clutch is slipping and grabbing. It's not a slipping clutch as the feeling lacks the "slip" and is all that jerky/grabby (no, it's not a porno shoot) feel. Link to comment Share on other sites More sharing options...
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