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Check for LASOAB

Yes, I know this has been asked a billion times, but I haven't found a solid answer in my hours of digging

I'm immature and want flames out of my exhaust. I've already played with KFTVSA, KFZWMN (and the other timing maps), and KFLF, and I can get some good loud noises, but I'd rather have a quieter noise with a big flame out the back. How can I add more fuel in low load? It looks like the only option to adjust low load fueling is KFLBTS, but being the temperature-triggered map it seems like I should be using something else to richen the mixture. KFLF doesn't seem like the right way to go, and LAMFA only appears to be load 80 and up (but my definition has broken axes).

I'm also not sure if there's a way to trigger open-loop fueling on overrun that anyone knows of.

If anyone else knows how to get those huge flames (like red and billowing, not the jet-like ones you get on a really powerful bang), I'd like to know since I'm also not sure how to ignite it other than the hot turbo. Yes, I know this probably isn't great for the car.

ECU is 4b0906018P, 2000 A4 1.8t ATW

Since we are in the noob questions area... Why is the idle stabilized only with ignition timing but not also with injection time ("load")? I get it that the engine runs quite inefficiently at idle with retarded timing. Why not use an ignition timing map (rpm/load) similar to the one for normal driving? The idle speed feedback controller would simply request load and look up timing, that would be the logical and efficient way to do it IMO.

Post logs
First of all check misol for torque intervention, especially migs_w

Hi all,

Coming here after almost 2 years of frustrations with a power cut issue under full throttle.

Have a A5 2.0T CDN 8K5907115 with a hybrid k04 turbo, but 3rd gear and up I'm getting throttle closing at around 5k rpm.
Issue started on a previous tune when I moved cities from a high altitude (1400m) to the coast. Never had issues at altitude and was making around 280kw (reported on VCDS)
Decided to take the tuning into my own hands, bought all the hardware etc, but the car is still replicating the same issues.

I've logged pretty much all the usual suspects: rl, rlmax, rlmx, ldrlts, rlsol, ps, psol, frxt, mifa, misol etc.
rlsol seems to be the main culprit that starts dipping and causes the rest of the variables to follow the same by cutting boost, dropping load etc.
There is slight knock intervention, but only in 3rd gear and between ~3000-4000rpm but 4th,5th doesn't have any of that. Increased fuel pressure to 17bar and running it richer to compensate for our 95 RON fuel and nothing changed as it sometimes also stuttered as if it's a fuelling issue. KFMIRL and KFMIOP are the inverse of each other as well, so it's not that.

Is there anything else I should be looking at that will affect rlsol? Pulling back the torque definitely will get rid of the issue and at like 80% throttle the issue doesn't exist either.

Things to note that may have an influence:
Stock filter
Aluminium boost pipes
R8 coilpack
Running colder spark (BKR8EIX)
DV vent to atmosphere
Decat with lambda fooler
Running Stage 2 TCU tune

52k slow init I just did it 4min

I think I dropped enough hints where you can figure it out yourself.
Patch is just annoying to make because of so many places that need modding, and one place with a trick (if you wrongly mod it without knowing what it is, you will have funny results).

I was not talking about a stock software in that example but rather a custom software written by a professional tuner. In such a case, my logic was correct?

I'm not gonna tune it myself. As I said, I'm collecting information so that I can ask potential tuners some questions and weed out unprofessional ones. For example, one tuner has already told me he'll simply increase max torque to 800nm and it will work, heh. If it wasn't for this forum, I'd have believed him.

Your assumption is that there's this sea of tuners who know how to properly tune the DQ250, when in reality it's possible to count them on the fingers of one hand.
Everyone else will just buy the tune from one of these or fail spectacularly.

If you are already working with TVS, then go to TVS and tell them what you need and pay your money instead of screwing around.

99.99% of "tuners" do not understand this box whatsoever.

Hi marantz,
I get the impression that the table might be a "linearization map" as can be sometimes found on the net. Like it is a correction factor between the PID output and actual duty. In that case, the output duty could never go higher than the last row in KFLDTV, and that was basically my observation. I was getting a constant and predictable underboost with a relatively low N75 duty, the ECU did not want to increase it even for a several second long underboost. On a closer inspection, the N75 duty was close to the last row in KFLDTV. Raising the values fixed this problem without issues.

Well, the axis of the table is LOAD. If you run more boost, you have more LOAD, so you are automatically pulling numbers further from the table, which are naturally lower. So even without altering KFZW and increasing only boost and fuel, you get less timing, ig your timing table is sensible.

by the way, WOW, I just logged timing pull for my other AUM engine (110kW), which has been remapped to factory AUQ maps (132kW). The engines themselves are identical so this shoud be a perfect fit. But, I am getting a steady 6° retardations for a WOT pull, some numbers are even higher. This is much more serious than my little 2s for AGU tune and basically with factory maps. The car is mapped like this for maybe 2 years, almost daily driving and there are absolutely no issues with it. And an interesting finding, there is always 0 pull for cylinder 1. This is the same for AGU and AUM.

Thanks again for the discussion.
Jan

Hi doktor.

I have logged N75 duty cycles higher than those on KFLDTV, almost 10% higher than those on the map. My car was mapped in winter when air is colder and denser, so on summer the turbo had to work almost a 10% extra to move the same air quantity. I did notice the car behaving ever so slightly different when it started the hot days here, and as obssesed I am with this I ran some logs and noticed it. Leveling out KFLDTV has allowed me to keep the same behaviour and performance all year around even though we have like 25-30ºC difference between winter and summer here where I live.

I believe (but cannot confirm) a "perfect tune" would have compensate the PID maps somehow for this kind of cases, as it is not the same having to do compensation work for 0,5bar than for 1 or 1.1bar, or even more in the future (bigger turbo incoming). But I do not understand the PID maps yet, it is some work I still have to do. If someone knows about it, I would appreciate it a lot if you could chime in and give some insight about it!


About timing: how are your spark plugs and coils?  When I was on stock tune, I had 3-4º of timing pull with the plugs the car came with, and with a fresh new set (PFR6Q for 1.8t AEB), it went down to zero. With my actual tune I only get occasionally 1-2º of timing pull on 95 octane petrol. With 98 (highest available in my area) it is basically zero.

Let's keep this chat up, I haven't had many opportunities to be able to have a long chat about discoveries with this ecu.

Best regards