Experimental RomRaider Definitions

[RallyMachine]

It appears the AF3 codes worked for me, although RR only gives me the option of logging AF3 Correction, not Learning.

 

Also, my AF3 Correction (32-bit) values are 0, but RR gives me an option of logging AF3 Correction (16-bit), which was -50.00 at idle. I don't think this was being applied but I'm not sure.

 

Overall, much more stable AF reading when driving around! Highly recommended to anyone with the rear O2 sensor removed.

[covertrussian]

Nice, glad to see it helped! 16Bit values will jump around, but they are useless to us 32bit guys.

[RallyMachine]

Great, thanks for all the help.

[Th3Franz]

Ok thanks I will check those out. What are the overrun tables for?

 

Overrun table affects throttle tip-out fueling and deceleration fueling & spark. I had to adjust mine quite a bit for my lightweight flywheel and lightweight crank pulley.

[hadvw]

32 bit Subaru's, use the wideband front sensor, but they also use a dummy narrowband rear O2 sensor to adjust the fuel trims too.

 

Your rear O2 sensor is a dummy narrowband sensor, as in it only sees 14.7 AFR, if your below that your rich, if your above that your lean. Lots of cars use this kind of O2 sensors as the main front sensors, so it's not a bad design. O2 sensors have a filament in them that gives off a certain voltage based on the oxygen presence in the exhaust.

 

TL;DR Removing Rear O2 sensor causes your car to be rich while cruising causing poor gas mileage.

 

Just curious: if I still have my rear O2 sensor (and recently replaced it, so it should be working), but the tuner disabled it in the tune, could that still lead to poor gas mileage while cruising?

 

My car has recently gotten noticeably worse - around 15 mpg in town, maybe 18-20 highway if lucky - than before. I've been using tunes from Tuning Alliance and throttlehappy. Car drives GREAT, and using learningview, tables are fine last time I checked. Not too worried about the 15 mpg in town - after all, I have a bnr16g, 650cc injectors, and I'm not a "relaxed" driver . But, I was hoping to still get close to 22-23 mpg highway, and while I don't do long trips anymore, even mixed driving is sitting around 16 mpg, which says that highway is way lower than I would expect.

 

btw, as far as the experimental definitions, I had great success adjusting the fuel mpg compensation co-effficient. I believe stock is 9 for 550cc injectors. Using 650/550=1.18181 * 9 = 10.63629. I think I used 10.8, and that has worked out to be almost dead on for my 650cc Deatschwerk injectors compared to miles/gallons calculated at fillup time. Except now I never look at it to avoid becoming depressed

 

Also, I have a walbro pump - should I adjust my fuel pump duty cycle? I haven't seen the definitions for that one before - any hints?

[Underdog]

Started digging into these definitions as part of chasing down my wildly rich A/B/C trims. I am using ROM A2WF200N for my USDM '06 LGT 5MT. My tuner had provided me a modified A2WC511N, but the neutral position switch changed from normally open to normally closed on the '06+ models, and using the '05 map causes the ECU to read the NPS incorrectly, preventing use of cruise control at a minimum. I ended up copying over all the tables I could see from his map to a copy of my original F200N map, and may have overlooked AF3 correction since I did not have it defined.

 

Anyways, I searched RomRaider and found the following info posted by td-d:

 

Is there any way I could get what would be needed to be added to the definition for being able to remove all the Rear o2 corrections on this legacy GT rom? A2WF200N

ROM:0002EC58 AF3_Correction_Limits
ROM:0002D648 Rear_O2_Comp_Limits:.float -0.5 

 

Thread: http://www.romraider.com/forum/viewtopic.php?p=89391#p89391

Posted: Mar 15, 2013 2:09 pm

 

Adding the following code to my ROM definition yielded the tables in ECUflash as shown in the attached screengrab.

    <table name="AF 3 Correction Limits" category="Experimental" address="2EC58" type="2D" level="1" scaling="A/FLearning#1Limits(%)">
       <table name="X" type="Static X Axis" elements="2">
           <data>High</data>
           <data>Low</data>
       </table>
   </table>

   <table name="AF 3 Learning Limits" category="Experimental" address="2D648" type="2D" level="1" scaling="A/FLearning#1Limits(%)">
       <table name="X" type="Static X Axis" elements="2">
           <data>High</data>
           <data>Low</data>
       </table>
   </table>

[covertrussian]

Just curious: if I still have my rear O2 sensor (and recently replaced it, so it should be working), but the tuner disabled it in the tune, could that still lead to poor gas mileage while cruising?

 

My car has recently gotten noticeably worse - around 15 mpg in town, maybe 18-20 highway if lucky - than before. I've been using tunes from Tuning Alliance and throttlehappy. Car drives GREAT, and using learningview, tables are fine last time I checked. Not too worried about the 15 mpg in town - after all, I have a bnr16g, 650cc injectors, and I'm not a "relaxed" driver . But, I was hoping to still get close to 22-23 mpg highway, and while I don't do long trips anymore, even mixed driving is sitting around 16 mpg, which says that highway is way lower than I would expect.

 

btw, as far as the experimental definitions, I had great success adjusting the fuel mpg compensation co-effficient. I believe stock is 9 for 550cc injectors. Using 650/550=1.18181 * 9 = 10.63629. I think I used 10.8, and that has worked out to be almost dead on for my 650cc Deatschwerk injectors compared to miles/gallons calculated at fillup time. Except now I never look at it to avoid becoming depressed

 

Also, I have a walbro pump - should I adjust my fuel pump duty cycle? I haven't seen the definitions for that one before - any hints?

 

Man I completely missed this couple years ago!

 

Rear O2: It depends on how they disabled it. Most people disable it via CEL only and not fix the AF3 Correction tables. I actually zeroes out the AFR3 corrections even with the stock down pipe and I think that helped my MPG a little bit. 100k miles on old O2 sensor and it was stuck, so couldn't remove it to replace it, that's why I simply disabled the adjustments

 

I'm surprised throttlehappy tune would give you that low of MPG's, he seems to really know his stuff when it comes to MPG tuning (one of the few tuners I've seen that even cares about MPG's ). Have you licked everything else over, boost leaks, spark plugs etc? I have the same turbo minus the injectors and get 20/30mpg in warm weather.

 

I believe Walbros don't like 33% duty cycle fuel pump settings that stock tries to run, same goes for most aftermarket pumps. 05's now have a definition to be able to adjust the duty cycle steps

[Underdog]

^ I've just added the following code to enable the fuel pump duty cycle table on A2WF200N and it resulted in table shown in the attached screengrab. I am running a DW65c pump, and may try increasing the duty cycle from 33/66/100 to 50/75/100, but need to do more research first.

 

<table name="Fuel Pump Duty" category="Experimental" address="3BA44" type="2D" level="1" scaling="rawecuvalue">
     <description>The ECU will set fuel pump duty cycle to 0%, 100%, or one of these two values.</description>
     <table name="Fuel Pump Duty" type="Static Y Axis" elements="2">
        <data>Medium</data>
        <data>Low</data>
     </table>
  </table>

Credit to NSFW and td-d. http://www.romraider.com/forum/viewtopic.php?f=40&t=6356

[Underdog]

Has anyone looked at the ability to add fuel pressure differential compensation to our ROM? This would be applicable to those of us who've added a 0-5V fuel pressure gauge/sensor on the TGV signal line, for example.

 

Cobb seems to have unlocked this capability within a Subaru ECU, although it isn't immediately clear which.

 

https://cobbtuning.atlassian.net/wiki/plugins/servlet/mobile?contentId=26870434#content/view/26870434

[utc_pyro]

Has anyone looked at the ability to add fuel pressure differential compensation to our ROM? This would be applicable to those of us who've added a 0-5V fuel pressure gauge/sensor on the TGV signal line, for example.

 

Cobb seems to have unlocked this capability within a Subaru ECU, although it isn't immediately clear which.

 

https://cobbtuning.atlassian.net/wiki/plugins/servlet/mobile?contentId=26870434#content/view/26870434

 

You'd need to ether make a parch from scratch or MerpMod and use that framework. Cobb adds a chunk of custom code to the ROM when you load it, and this appears to be part of that.

 

A patch wouldn't be TOO hard in theory. Hijack a unused 2d fuel compensation, feed it a memory address from the TGV sensor. You can do that in a hex editor while referencing IDA. To do it right though, you'd have to actually compile code and inject your new function into the fuling code. Serious learning curve, I think NSFW is the only legacy guy to do that kind of work as part of his flatfoot shifting patches.