Ok last thread jack, NJ1266 what do you think about rescaling the maf to cleanup LTFT? Seems like these are the three ways: scale maf, scale injector/ latency, or use hz crossover. To me the one that should have the least affect on other tables is adjusting latency like you said but a lot of people say never mess with stock injectors. I mean shouldn't it be safe since if I bump latency up .05 that should make the car a little richer to compensate for the open cone. Making the car richer seems safer than scaling a maf? Thoughts? I'm hitting 12 and 10 idle and cruise now. It's got to be the intake and weather really making my car run lean.

 

Does the cone filter you have replace the pipe where the airflow sensor is mounted or is it just the airfilter leaning out things 10-12%? If it is a 3" pipe where the airflow sensor mounts then doing a +10% MAF compensation seems like it would bring everything back in line. I've done small tweaks to the stock injector scaling and latency to adjust for mods, but as we just confirmed the injector scaling will effect the WOT tune.

Also make sure you are resetting the ECU after making changes or the LTFT's may calibrate incorrectly. I've seen my car hit +8% after making a change without a battery reset and once I reset the battery it never ventures past +-2%.

 

I have been working on my mas calibration because I installed a K&N cone filter onto the mas housing. I had it dialed in so it generally ran around .92 to 1.5 wich is pretty fair. I have been monitoring it continuously with my ap for a couple weeks. Last week I filled up at a shell, wich in my area sometimes has up to 15% ethanol in their gas. (I normally don't use Shell gasoline for this reason). After about an hour drive, I noticed that my LTFT had moved to 6. This is something to keep in mind when adjusting for fuel trims, wether it be mas calibration or injector tuning. I am swapping injectors out next week, and now I have to make sure I purge all of that gas out, or my fuel trims won't be of much use to me, because they won't be accurate because the fuel is so different. At least with my surge tank I can just pop off an AN fitting at the inline pump, so I won't have to remove the seat to pump all the gas out. I still have to run the car below 1/4 tank long enough to empty the right side of the gas tank though.

 

I just have a cone filter, no piping.my friend and I flashed the ecu with 472 injector scaling and the fuel trims seem to have settled. I believe the fuel trim resets each flash on the ix. We did have to retune the WOT ranges and lean them a little. Jut not sure of te side effects of scaling stock injectors but at least the LTFT are within range now. How does this work in theory though? I added cone filter which caused the car to see lean conditions and therefore add fuel in closed loop. The fuel trims then carried over to my WOT causing a 1 point afr increase. By scaling the injectors to 472 my car now adds more fuel in closed loop so the fuel trims do not rise as much and in turn do not greatly affect Wot afr?

 

I have not seen any side effects on my Evo 9. I drove with 472 scaling for a long time before going with bigger injectors. I had no problems at all.

When you lower the scaling the injectors add more fuel. The lean condition that was noticed no longer exists. So the trims do not go positive anymore. That fixes the problem. It worked really well on my Evo 9.

 

So far so good. Thank for the help. The theory makes sense, I'm glad you posted that thread and detailed what you went through. I debated putting stock box back on but the problem probably would have persisted. I am just suprised not many evo ixs have had this issue, that or maybe they do not log afr enough to noticed a change after LTFT settle