RomRaider

Nope there should not be any problems.

Quick couple of (newbie) questions...

Would you see any issues with using this base map with a 2005 EJ253? I ask only because in my attempts to adapt it such, I have gotten some annoying running rich issues, which I suspect could also be contributed to the vvi system that it does not have...

you mean EJ251? i dont think so. this is for VVL engines.

Hey I tried this map on my 09 Impreza m/t and wow huge difference! I started some scaling changes which also is making more improvements. Just curious but since I have a manual trans and run 91 octane could I give it a bit more timing? I was hoping you might be able to help me understand what to change and why? I understand the theory of changing everything but there's really no info out there for a step by step run through of what each table is. Like why there is a b c d and what they do. Or would you look at my rom if I posted it? Thanks again!

hey this map was not my final commercial tune. Just sort of the free version. i found on dyno that there was no point going past 25* timing at full throttle at ~6000 rpm where max peak HP is realized. so you can switch to 91 octane if you like but you wont change your peak HP. higher octane does let you add more timing in more troubled regions like 1600-4600 rpm area but only about 1.44-0.35* additional. in my mind the 2-3whp gain is not worth the additional cost at the pump.

The 2005 Forester came with a SOHC EJ253 w/ MAF...

Do you know if this can be applied to EZ1GB00H. I can send my bin / def if needed but I'm looking to both make the car a little more fun as well as save on gas (by running a little more efficient). I try to port your maps tomorrow.

Thanks,
Cj

yes just copy paste but be careful plz.

I'm not new to tuning by any means so that's what makes this so much fun.
Your maps work well, but what I'm running into on my 08 is that i can barely push on the throttle and it's like pushing 1/4 the way to the floor. I noticed my stock DBW maps are that crazy hump looking map which means I'm probably going to have to do some logging and tweaking. Here's what I've got so far, is there something I maybe missed? I'm trying to tune out a roughness issue and idle drop when slowing down to a stop. Intake on the car is stock, and exhaust is axle back so not really any airflow changes. Your modified base maps for fuel and timing work great but i do have a bit of a popcorn crackle on deceleration as well and when watching the ECU I see the engine take a bit to go 0 duty cycle when I pull off the gas now vs on the stock ECU.

FYI, I've got the 08 USDM Impreza 2.5 NA (EZ1GB00H). I'm guessing the ECU is different enough from the 09 that I can't run the EZ1E401H code.

hey you did Not copy the throttle / DBW tables correctly. You forgot to copy over the RAW ecu / torque values for Target Throttle Plate Position A, B and max. This can be dangerous, fix this asap. Just use RomRaider to wholly copy a table and paste it in your rom. This ROM is for 09 4EAT, do not flash this rom to your ECU, you can use its tables as reference. To remove pops and crackles advance base idle timing (in gear) above 1000 rpm to BTDC timing (10-15*).

Will do. Does this tune improve gas mileage as far as you can tell? Or do you have one you've been working on that does? i've run into trouble trying to get the car to run in leaner modes. I can't seem to trick the ECU into doing much past 15.01 target AFR and open loop has been even crazier.

I recopied the tables to my rom. Oh man car runs way better. I see a slight improvement in gas mileage. I'd still like to try to figure out lean burn in cruise. I do a lot of highway travel and any gas mileage I can save is worth it.

lean burn not possible on stock ECU due to EGR problems. Once the EGR valve opens and egr kicks in ECU will force closed loop mode no matter what. The open loop leanburn mode you talk about works great on WRX/STI that are not equipped with EGR system (they use AVCS). Also underestimating the MAF voltage to induce OL leanburn can be dangerous since it will affect your load reading across the board. You can end up running too much timing and too little fuel specially in areas where a system table has not been defined.

Hi Pickler,

Thanks for your reply. I was on the ecomodder forum and was told by one of the users there you had tuned their ride for higher AFR's. I'm interested in starting with a high fuel economy map and going from there. I've experimented with adjusting the close loop parameters and retarding timing but the gain for ~4mpg isn't that much.

Mostly with the 08 my goal is to try to get it to save a little gas.

I did notice some economy gains with remapping the DBW which is part of that ~4mpg.

It sure is a bit different than tuning on the older GM platforms with Moates hardware and tuner pro but not much. Still the same basic concepts.
Thanks for all your input. I'll post on RR if I find any new maps/parameters in my decompile of the base rom.

The 2.5L SOHC with AVLS just doesn't like lean conditions and the EGR system is too intrusive. i could not find a way to disable the egr from the ecu. maybe td-d can help with that. With the wrx and sti since the egr is induced by avcs and it has low compression heads, its easier and more productive to do lean burn. lean conditions reduce engine reliability and performance in ej253. this is not like any other engine i have tuned. it likes to run rich and often knocks leaner than 13:1 under load at any rpm. i have witnessed it actually gain power on the dyno running pig rich at 11:1 with more timing vs moderate timing at standard mixtures. i say just give it whatever fuel it needs which is often ~12.5:1 on pump gas above 1.2g/rev and 14.5:1 cruise with timing in 40s. for me stock map always resulted in worst power and performance but best fuel economy. beware that hot tempratures from stoich or lean conditions will cause premature headgasket failure due ti very high cylinder tempratures. even though it is much less powerful than the ej255, the ej253 experiences almost the same cylinder head and exhaust temps. its a 'hot' engine. also the AWD requires lots of torque and running lean will result in bigger throttle openings quickly. the car will just feel very sluggish.