Target AFR not following fuel map [Ecutek]

[SumDizzy]

I'm in the process of self tuning my 2018 turbo'd 86. I'm using Ecutek's Forced Induction tuning guide as a jumping off point. Given their guide and tune is based off a 2013MY EU car, there's probably some differences I haven't been able to surface on my own yet.


I've run into an issue where during a 3rd gear WOT I hear a very unpleasant noise from the engine around 5k RPM. I've never heard anything like this before, but I'm chalking it to aggressive knocking because I believe my AFR is too high. Here's the datazap.


Interestingly it seems like my target AFR refuses to drop to where I have my fuel map tuned to. Where the engine speed peaks at 5300 RPM, the datalog says both my AFR target and actual are around 14.3. If it was following my fuel map, the AFT target (at least) should've been 11.6. Hoping someone can point me in the right direction.

[callisto]

Originally Posted by SumDizzy

I'm in the process of self tuning my 2018 turbo'd 86. I'm using Ecutek's Forced Induction tuning guide as a jumping off point. Given their guide and tune is based off a 2013MY EU car, there's probably some differences I haven't been able to surface on my own yet.


I've run into an issue where during a 3rd gear WOT I hear a very unpleasant noise from the engine around 5k RPM. I've never heard anything like this before, but I'm chalking it to aggressive knocking because I believe my AFR is too high. Here's the datazap.


Interestingly it seems like my target AFR refuses to drop to where I have my fuel map tuned to. Where the engine speed peaks at 5300 RPM, the datalog says both my AFR target and actual are around 14.3. If it was following my fuel map, the AFT target (at least) should've been 11.6. Hoping someone can point me in the right direction.

Does it sound like a tin can resonating at 4600-5100rpm, like the cylinder is hollow and echoing suddenly, and then go away?

[tomm.brz]

you have touched something that prevent the ecu go into open loop mode
maybe you lowered the Minimum AFR for open loop table?

Put the 2 lean closed loop tables the same as your main Fuel map
afr target is 14.4 because you are forcing it into closed looop and that s the target at the moment

You can send me privately your tune if you like, i give a quick look at "basic" things and tell you if something is off

[SumDizzy]

@callisto I can't say for sure, I guess it kind of had a tinny sound. I stopped immediately once I heard it, so I'm not sure if it goes away with a higher RPM. It's not just an issue with RPM as I only hear it when I do a WOT pull. Just cruising and slowly building up to 5-6k rpm hasn't been an issue.

@tomm.brz That was my first thought, but I'm not sure what tables control open loop. All three of the Function -> Fueling -> Open loop tables still have the same value as the stock rom, including minimum afr open loop. I'll send my tune shortly.

Also the closed loop afr maps are restricted because I'm using a USDM stock rom.

[AussieBRZ]

uas based ROMson 2017+ cars seemto have a lot of errors and weird issues in the ecutek racerom patches, causing all sorts of weird issues including weird lean areas where afr doesn't follow open loop maps and seems to target 14.7 afr for periods.


Seems to happen with reacrom 12 versions sometimes I've has to go back to recerom 11


The euro maps/raceroms are far less error prone than USA ROMs ,if you can switch to euro K00G or K01I

[tomm.brz]

yeah then probably is both bugs and ecutek limitations
I saw your mp will take a look soon

[callisto]

The tinny noise can be reproduced with a healthy engine in stock untuned ROM on a steep uphill in 1st or 2nd, just accelerate smoothly uphill and you’ll hear it after 4500 rpm. It only occurs under load so you’ll never hear it while cruising. I’ll link the thread once search is back up.

[SumDizzy]

@AussieBRZ @tomm.brz Thanks for the input. I recreated my tune based on an EU rom, but still see the same issue. I'm pretty confident I haven't changed anything besides the tables mentioned in the ecutek guide. I used the 12.3 RaceRom patch. I can try version 11, but thought I'd wait to see if there might be any other ideas.
@callisto That's somewhat reassuring. The noise still occurs with the EU rom, but it has a more consistent whining sound as opposed to before where it sound slightly grindy/coarse.

[callisto]

Yeah, it’s quite the noise. I’ve personally heard it on a 2013 with K00G and on a 2019 with K00G, S10C, and U01A.

[tomm.brz]

how did you put a k00g into a pre restyiling they re not really compatible
The sound must be the mix of lean afr, weird camshft positions(as they are in stock form in latest oem calid) too much DI and too high of timings lol

[callisto]

Originally Posted by tomm.brz

how did you put a k00g into a pre restyiling they re not really compatible
The sound must be the mix of lean afr, weird camshft positions, too much DI and too high of timings lol

I didn’t, sorry, wrong ROM code. I’ll look it up later but it was whatever was tuning popular back then.

[tomm.brz]

Originally Posted by SumDizzy

@AussieBRZ @tomm.brz Thanks for the input. I recreated my tune based on an EU rom, but still see the same issue. I'm pretty confident I haven't changed anything besides the tables mentioned in the ecutek guide. I used the 12.3 RaceRom patch. I can try version 11, but thought I'd wait to see if there might be any other ideas.
@callisto That's somewhat reassuring. The noise still occurs with the EU rom, but it has a more consistent whining sound as opposed to before where it sound slightly grindy/coarse.

haven t really seen ur tune yet but i ll do and will find what s wrong and fix it for you

US rom sounded different because it has an extra closed loop fueling active which is active even in open loop even until limiter, if the afr target is leaner than 12.6
so probably you run leaner on US calid

[tomm.brz]

Ok the only things i see wrong in the US tune you sent me are
fuel cut resume must be higher than 1.33, put 2
PI to DI% avoid 0% at full load, insert more PI like 20 or 25% at mid rpm high load
Cam timings are kept stock and are inadeguate, try stage2 OTS cam timing and remove 4 Degrees from both intake and exhaust at high load and you are more in the ballpark
Put fuel map lean closed loop the same as you main fuel map (stretch it eventually)
Make afr a bit richer from low rpm to mid rpm
Copy paste exactkly main fuel map into Power AFR maps but it s tricky as it wants under 12. 6 to go into open loop so then modify , over 1.1 of engine load, the cells that are over 12.6 afr and put the like 12.4
Modify Exhaust manifold temp threshold lowering overall of 300 degress, this way you could bypass the power afr maps
Enable ticks on all maps on "Closed loop fuel control options"

i would not use N10C cal with latest racerom, since it seems you re still able to convert calibrations, if you switch to euro rom you could use K00G as it doesn t have any power afr maps and quite free of bugs with 12.1 racerom
Also Q00G and S20G seem ok but they have the power afr maps

[SumDizzy]

Originally Posted by tomm.brz

Ok the only things i see wrong in the US tune you sent me are
fuel cut resume must be higher than 1.33, put 2
PI to DI% avoid 0% at full load, insert more PI like 20 or 25% at mid rpm high load
Cam timings are kept stock and are inadeguate, try stage2 OTS cam timing and remove 4 Degrees from both intake and exhaust at high load and you are more in the ballpark
Put fuel map lean closed loop the same as you main fuel map (stretch it eventually)
Make afr a bit richer from low rpm to mid rpm
Copy paste exactkly main fuel map into Power AFR maps but it s tricky as it wants under 12. 6 to go into open loop so then modify , over 1.1 of engine load, the cells that are over 12.6 afr and put the like 12.4
Modify Exhaust manifold temp threshold lowering overall of 300 degress, this way you could bypass the power afr maps
Enable ticks on all maps on "Closed loop fuel control options"

i would not use N10C cal with latest racerom, since it seems you re still able to convert calibrations, if you switch to euro rom you could use K00G as it doesn t have any power afr maps and quite free of bugs with 12.1 racerom
Also Q00G and S20G seem ok but they have the power afr maps

Thanks for the insight and info, appreciate you taking a look. That explains my original issue. I can find almost no info about the power afr table, is there a place I can read up on it or do most tuners ignore it (opting for the K00G map). Also I tried flashing the K00G map, but Ecutek complained that it wasn't compatible - is there something I need to do? I'm currently using the Q00G map and all the suggestions you've had more or less fixed the AFR issue. Currently working through closed loop maf scaling and will take a stab at open loop scaling once I get past this next issue:

Despite my fueling now hitting the afr target, I was still having an issue with audible knocking. Even zeroing the advance table did not help. I thought the ignition table from the ecutek guide would get me in the ballpark, but I think they're way too aggressive for what I can do on 91 octane. I've opted to take the "vvt off" ignition base table from the OFT stage2+ tune and interpolate it out for the load I'm doing. Just doing a quick check, the total timing is 5 - 10 degrees retarded in the cells I was seeing knock. Haven't really tested yet, but some partial pulls have me feeling a bit more comfortable. My current goal is to keep fiddling with it until I can eliminate most serious knocking - after that I'll start adding timing back and finding more appropriate afr targets.


I've probably lowered the life expectancy of my engine, which is not what I wanted, but I'm not sure how else I was going to jump into software tuning. If you know of any other sources I can learn from, it'd be much appreciated.