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Author Topic: Fuelling maps  (Read 1492 times)
nyet
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« Reply #15 on: February 15, 2021, 03:15:10 PM »

Sigh...
It's there so that the engine doesn't melt when it gets shit fuel.

In fact that path has nothing to do with KFLBTS. KFLBTS is the base path. KFFDLBTS * DLBTS is the additional path which enriches with a delta lambda based on ignition angle efficiency.
Setting it to zero is stupid, as is tuning BTS without having EGT measurement, because you can never know how much it needs to not melt.

I really don't like your last sentence though.
"I don't get the point of X, it just complicates things".

With 91oct i have to run deep into 10/11 anyway, so BTS based on ignition angle isn't going to do me any good - at load there is never good angle efficiency, period. May as well just run pig rich all of the time at load or WOT. So for shit gas, you can, actually, just set to zero to simplify tuning.

In theory, once you have that set up, you can unwind it, but you'll NEVER be out of DLBTS anyway, so what's the point?

I know this isn't the "right" way to do things, but for a first pass and to get a feel for how BTS/LAMFA/ATR interact it isn't going to kill you if you have an aggressive BTS/LAMFA to start with.

If i run shit gas worse than 91oct, i go from shit 5 deg to shit 0 deg timing, upon which i can always enrich via KR.
« Last Edit: February 15, 2021, 03:17:47 PM by nyet » Logged

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prj
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« Reply #16 on: February 15, 2021, 04:15:47 PM »

at load there is never good angle efficiency, period.
That's why DLBTS does not start from 100%.
Quote
In theory, once you have that set up, you can unwind it, but you'll NEVER be out of DLBTS anyway, so what's the point?
Why would you not be? Nothing stopping you from modifying the map.
Quote
If i run shit gas worse than 91oct, i go from shit 5 deg to shit 0 deg timing, upon which i can always enrich via KR.
By this logic you can say - why use BTS at all, just dump fuel all the time and use KFLAMKRL/KFLAMKR.

And yes you could do that in theory, but BTS provides better fuel economy and better control.

If you are disabling KFFDLBTS/DLBTS and setting thresholds low, then I'd disable the entire LAMBTS module.
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Sandstorm3k
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« Reply #17 on: February 16, 2021, 04:33:11 AM »

This is exactly where part of my confusion comes from. One says this and the someone else says something different.

I exclusively run my car on RON98 which should corrospond to 95OCT.

Now to me personally it makes more sense to tune BTS with DLBTS zero'd out. It looks like it simplifies things, and i'm really trying my best to understand why and how I do some things. Now i can see why these files also zero'd DLBTS. Probably might not be the "right" way indeed, but if it works properly and doesn't cause any further complications i could'nt see why i woulnd't want to do so.

Anyhow got a vacuum problem regarding my N75, tried two different valves so will be replacing some hoses now. (bad overboosting problems on stock software) Runs properly on wastegate pressure with N75 disconnected. Need to get this sorted before i can do any further testing & logging.

Will get a 3rd/4th gear pull on here when i solve the issue and flash my own file on.

I do very much appreciate all the input
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prj
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« Reply #18 on: February 16, 2021, 06:03:19 AM »

It works until the "98" you fill, accidentally turns out to be 95 (or worse) and you melt the engine because there is no more enrichment happening with degraded efficiency.

If you don't get the BTS model, turn it off and adjust fueling via LAMFA, KFLAMKR and KFLAMKRL.
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nyet
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« Reply #19 on: February 16, 2021, 06:03:22 PM »

If you don't get the BTS model, turn it off and adjust fueling via LAMFA, KFLAMKR and KFLAMKRL.

I would suggest this anyway for a noob trying to learn ME7 AND trying to tune fueling with stock narrow bands + wb sniffer.

having BTS constantly fuck with with your req afr makes it a huge PITA

Yes, they may melt pistons, but with a rich enough LAMFA and a conservative enough LAMKR it is doable. Then, when they get it figured out, they can pull back LAMFA and bring back BTS to get decent fuel economy and stay safe at the same time.

With a stock WB car, leaving BTS in place is actually way easier, because you have the ECU doing the trimming for you. req lambda is truly set and forget, tuning fuel is just a matter of minimizing long trim adaptations.

Again, this is my opinion. There are a million different ways to implement fueling. Totally up to you.. the problem is, it is hard to make an informed decision until you *understand the entire fueling path* from start to finish.
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ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
Sandstorm3k
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Leon 1M 1.8T AUQ


« Reply #20 on: February 17, 2021, 12:33:44 AM »

I would suggest this anyway for a noob trying to learn ME7 AND trying to tune fueling with stock narrow bands + wb sniffer.

having BTS constantly fuck with with your req afr makes it a huge PITA

Yes, they may melt pistons, but with a rich enough LAMFA and a conservative enough LAMKR it is doable. Then, when they get it figured out, they can pull back LAMFA and bring back BTS to get decent fuel economy and stay safe at the same time.

With a stock WB car, leaving BTS in place is actually way easier, because you have the ECU doing the trimming for you. req lambda is truly set and forget, tuning fuel is just a matter of minimizing long trim adaptations.

Again, this is my opinion. There are a million different ways to implement fueling. Totally up to you.. the problem is, it is hard to make an informed decision until you *understand the entire fueling path* from start to finish.
As i have got a stock WB car does it make sense to leave BTS stock then? And then only use LAMFA to enrich the mixture when required. I think LAMFA is a nice way, because it'll always enrichen the same because its based on requested toque rather than actual. Fuel economy on high load or WOT doesn't matter anyway. As i'll also be sure it has fuel and doesn't run too lean for some reason.

I've studied some community stage 1/2 maps, and for example the 1.8t a4 also left BTS stock, but rather only resorted to LAMFA to enrichen. Is this an acceptable way to do things?
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prj
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« Reply #21 on: February 17, 2021, 01:52:18 PM »

The stock BTS will enrich down to 0.7 on those that it is active as load goes up.
So something will have to be done with them.

If you have a 8L or 8N with k04, they don't even use BTS stock. Only LAMFA and ATR.
I don't remember if AUQ had it active or if it had an EGT at all. If you have an EGT sensor, then you can turn LAMBTS completely off, use LAMFA to run the lambda that gives you the best power (usually between 0.83 and 0.8 on these engines), and then use ATR for closed loop control if it ever gets too hot, which it should not unless you floor it for ages or get bad fuel.
« Last Edit: February 17, 2021, 01:54:19 PM by prj » Logged
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