Would you mind checking my VE tuning template?

[Mr. Smith]

They're saying exactly what we're saying - you just have to understand "what" they're saying...

No, you guys aren't saying what everyone else is saying. You guys here say that LTFTs are not averaged out STFTs. I've read it here since the day I signed up. Read Schpenx's posts above for proof. I remember reading a post from a well known member here saying something like "Why do people think LTFTs are an average of STFTs? They're not!".

(STFT) refers to immediate changes in fuel occurring several times per second. The long term fuel trims (LTFT) are driven by the short term fuel trims. LTFT refers to changes in STFT but averaged over a longer period of time."

What this means is that stft's are the quick changing and quick reacting responding fuel trims to the O2's... Long Terms are driven by st's - if st's stay (+) for a minute or so, then long terms learn this and are driven in this direction...

Yes. I made it clear that I know that and believe that.

For that reason - fueling as a whole is lt's+st's

Makes no sense whatsoever So you're saying because STFTs are instant fuel trims and LTFTs are an average of instant fuel trims (which I agree with), then you/we should combine/add the 2? Why? That's like saying "I smoke around 10 ciggies a day, so after a week I smoke 70 ciggies + 10 (long term weekly average + short term daily) which = 80 a week". Why would you combine them?

Do it how you like, but you'll be chasing your tail for ever if you leave lt's there and tune off of st's only...

I don't want to tune how I like.. I want to do it the right (+ easiest) way. If that means tuning your way, then that's fine with me. It's just that so far, I don't see how your way (and other posters here) is the correct way. It just doesn't make any sense (combining STFTs with LTFTs).

[tbrtuning]

LTFT does not come from averaging STFTs directly. There are many ways to learn LTFT that would be correct but it's learned from STFTs as it's correction factor. The goal of the computer is to have a LTFT so accurate the STFT can be at or near zero. It always makes corrections towards LTFT + STFT to fade out the STFT needed.

If fueling at a certain point is very consistent and an extra 10% is always needed LTFT will settle at 10% and STFT at 0%.

In this situation if LTFT started at 5% then STFT would be at 5% to get to the 10% correction needed. LTFT will continue to learn towards the 10% and less STFT will be necessary as the LTFT increases. When LTFT makes it to 8% only a 2% STFT will be necessary.

[GHuggins]

Something that might also help to visualize this, because I "think" this might be what your having trouble with...

Fueling is broken up into cells... This is represented as each individual Hz cell in the MAF table and each individual cell in the VE table... EACH one of the cells has a learned - "averaged if that's how you want to think of it" - lt fuel trim and a constant updated st fuel trim... You should be able to increase your rpms slowly and see lt's changing to demonstrate this unless your fueling is just that far off...

Long Terms are the learned to values from short terms... This is why fueling always = lt's + st's...

You don't have to get super defensive with everyone on here, which seems to be a pattern - mean no disrespect by this either - we're all here to help and or learn, but fueling is and will always be st's + lt's... Lt's may occasionally learn something screwy due to rich after flash conditions or whatever, but it's always one + the other...

[tbrtuning]

Resetting the LTFT with the scanner and watching an idle log as they learn is a good way to visualize it also. Just do it with a car already up to temperature. The initial LTFT + STFT will be close to what the final LTFT will be when STFT settles near zero.

[Mr. Smith]

LTFT does not come from averaging STFTs directly. There are many ways to learn LTFT that would be correct but it's learned from STFTs as it's correction factor. The goal of the computer is to have a LTFT so accurate the STFT can be at or near zero. It always makes corrections towards LTFT + STFT to fade out the STFT needed.

If fueling at a certain point is very consistent and an extra 10% is always needed LTFT will settle at 10% and STFT at 0%.

So what you're saying is.. LTFT is not an average of STFT..
and what I'm thinking is.. LTFTs = complete utter useless BS and we should just use STFTs as using them with LTFTs is completely unnecessary and overly complicated and the person who invented LTFTs should be hung by his testicles.
Thank you. Removing all things LTFT from my scanner and mind effective immediately. It's wasted enough of my time/life.

Something that might also help to visualize this, because I "think" this might be what your having trouble with...

Fueling is broken up into cells... This is represented as each individual Hz cell in the MAF table and each individual cell in the VE table... EACH one of the cells has a learned - "averaged if that's how you want to think of it" - lt fuel trim and a constant updated st fuel trim... You should be able to increase your rpms slowly and see lt's changing to demonstrate this unless your fueling is just that far off...

Long Terms are the learned to values from short terms... This is why fueling always = lt's + st's...

You don't have to get super defensive with everyone on here, which seems to be a pattern - mean no disrespect by this either - we're all here to help and or learn, but fueling is and will always be st's + lt's... Lt's may occasionally learn something screwy due to rich after flash conditions or whatever, but it's always one + the other...

Not sure if serious or trolling.

[schpenxel]

Honestly I'm not sure if you're serious or trolling at this point

Bottom line the computer uses LTFT + STFT. That's it, nothing more, nothing less. You can either disable LTFT's and just use STFT, some people just use LTFT, or you can add them together just like the ECM is doing and use them. Or you can chase your tail by making this way more complicated than it is

The computer adds them together and uses the total. The rest really doesn't matter.

[tbrtuning]

So what you're saying is.. LTFT is not an average of STFT..
and what I'm thinking is.. LTFTs = complete utter useless BS and we should just use STFTs as using them with LTFTs is completely unnecessary

I think the idea is if you are always running lean at a given spot and need 10% fuel added LTFT go ahead and add it to start with instead of hoping the O2 sensors respond quick enough to prevent a lean spike before they catch up.

If you think the corrections from STFT are instant and perfect then there's no reason to even tune the airflow model in the lower load areas that will stay closed loop. I'm not recommending this but that's basically the thought process of just allowing instant corrections and not trying to get a more accurate base value to start with.

[mbray01]

LONG TERM FUEL TRIMS ARE LEARNED VALUES BASED UPON SHORT TERM FUEL TRIMS. TAKE A LOOK WITHIN THE TUNE FILES, YOU CAN SEE HOW THEY ARE CONTROLLED. ONCE THE SHORT TERM READS UP OR DOWN A CERTAIN PERCENTAGE, IT INCREMENTS THE LONG TERMS THE SAME DIRECTION.

IF THE ECM SEES A SHORT TERM IN A SPECIFIC FUEL CELL OF +10% OVER AN EXTENDED PERIOD OF TIME IT WILL LEARN ITSELF TO A LONG TERM OF +10%, SO THE THE SHORT TERM FUEL TRIM IS CLOSE TO ZERO.

ALSO NOTE THAT SHORT TERM FUEL TRIMS ARE NOT STORED, BUT LONG TERM FUEL TRIMS ARE STORED. loNG TERM TRIMS ALSO CARRY, IE THEY CAN CARRY INTO POWER ENRICHMENT. THIS IS ANOTHER REASON WHY I TUNE WITH THEM OFF.

[Mr. Smith]

Honestly I'm not sure if you're serious or trolling at this point

Bottom line the computer uses LTFT + STFT. That's it, nothing more, nothing less. You can either disable LTFT's and just use STFT, some people just use LTFT, or you can add them together just like the ECM is doing and use them. Or you can chase your tail by making this way more complicated than it is

The computer adds them together and uses the total. The rest really doesn't matter.

Schpenx why would you think I'm trolling? All I've been saying is what my understanding of STFT/LTFT's has always been + what is written everwhere online (except here) which = LTFTs are an average of STFTs (period) and so combining/adding the two trims (3 + 6 = 9 for eg. so we are all on the same page) and using the total value (9) doesn't make any sense to me (what would make more sense to me is 3 + 6 / 2 = 4.5 to give you an average of the 2 trims).
And most people here say that LTFTs are not an average of STFTs and that we should combine/add them and go off the total number (and no one can tell me why + are instead telling me very simple/obvious things which I wasn't asking about and clearly already know as I wrote the same things myself here...).

I already said I'm disabling LTFTs (already have).. so I won't be chasing my tail.. and ever bothering with LTFTs again. I'm not coming back to this thread or reading any more about fuel trims because it's wasting my life away, is literally bad for my health and wasting your time too. Not worth it. Thank you for trying to explain this LTFT BS to me, guys.

[5FDP]

I don't have anything to add but this somes up my possible reaction.

[GHuggins]

I don't have anything to add but this somes up my possible reaction.

I like it

I'm not sure how many times it can be explained, just glad you disabled long terms.