You are correct if you say about sae stft, but its not working this way in sct style logging.
You are correct if you say about sae stft, but its not working this way in sct style logging.
Eastern and Central Europe American Muscle and Harley-Davidson tuning
www.hd-customs.pl
http://www.facebook.com/hdcustomspl
So how long does it take for LTFT's to be a useable correction factor per a given cell? Basically how much time do you have to spend in a cell? I like the fact that you don't have to disable anything in the tune for this method. I'm assuming you wait for an average of like 50 counts per cell?
Last edited by AKDMB; 06-19-2015 at 02:37 PM.
Please read my posts before. I usually dont wait long, just see what direction it goes and adjust manually, often without histo.
Eastern and Central Europe American Muscle and Harley-Davidson tuning
www.hd-customs.pl
http://www.facebook.com/hdcustomspl
Thanks for the input. When I heard that STFTs were the correction factor, I thought "hey that's simple" and was using it only. Then I noticed where it was lean and I corrected it, it was now rich by a large margin and I began to wonder what was going on and so began my quest to find out what method everyone was using.
It makes sense to me that LTFT would give a larger sample and should produce a better average for the correction.
My first corrections were from idle/rev logs and those corrections seem to be spot on, but when I started doing cruise logs, I was getting large (5-9%) STFT corrections in the cells I had already changed from the idle/rev logs. That's what made me start to question the method.
I appreciate all the input guys!
So just to reinforce my understanding of. using LTFT for MAF correction.
1. The LTFT is basically already a record of consistent STFT corrections for a given cell.
2.They get more and more precise over time as the PCM spends more time in a given cell.
3. When using LTFT nothing needs to be disabled to avoid "chasing you own tail" during the MAF tuning process. Less of a chance of screwing anything else up in the tune.
4. Just make sure the car is all warmed up and ready to go before you start to try to dial in anything, or you will chase your own tail.
Last edited by AKDMB; 06-20-2015 at 06:31 PM.
5. Use ltft only if stft are close to 0.
Eastern and Central Europe American Muscle and Harley-Davidson tuning
www.hd-customs.pl
http://www.facebook.com/hdcustomspl
That means you need to wait some time to ltft get stabilized. Thats why tuning using ltft only is not good, every tune write, they are reset.
Eastern and Central Europe American Muscle and Harley-Davidson tuning
www.hd-customs.pl
http://www.facebook.com/hdcustomspl
I look at STFT first (right after a flash so that the long terms are cleared) STFT is an instant correction. How much fuel the computer is adding or removing right now to get to stoich. You need to dial that in first or your long terms will be all over the place trying to make huge corrections both negative and positive. You want to get your STFT as close to 0% as possible. In reality you should shoot for 0-5% + or - because conditions are always changing, like the weather.
LTFTs are learned FROM the STFT. If a short term is consistent enough it will be saved as a long term and the STFT will start from that point. This makes the short terms quicker to react since they are correcting with the LTFT already factored in.
Once you feel you have short terms dialed in you can drive the car as you normally would for a few days. After that log the long terms and look for parts of the maf that are more than a few percent rich or lean. Sometimes when you dial in the short terms there are conditions that you were never able to log that use that same area of the MAF. You'll start to see these trends with the long terms and can farther dial in your part throttle.
It helps to have your STFTs already dialed in so that you are getting consistent data for your long terms.
I still consider myself quite the noob myself, but hopefully this will help you.
I apologize for asking on this thread but would anyone know the airflow limit on the stock Coyote MAF? I seem to be flat lining at 86lbs on the datalog so I'm wonder if I'm hitting a limit. Thank you.
2013 Mustang 5.0 A6
Procharger P1SC1 STGII w/4" pulley = 10lbs
DW 95lb Injectors
Lethal Performance O/R X-PIPE
Borla S-Type
-----------------------------------------------------
2016 Ford F250 6.7L
Stock
(#/min x 10) is a close estimate to the HP the engine is making at the flywheel. I think you are hitting the limit of your 10# pulley.
2013 Mustang 5.0 A6
Procharger P1SC1 STGII w/4" pulley = 10lbs
DW 95lb Injectors
Lethal Performance O/R X-PIPE
Borla S-Type
-----------------------------------------------------
2016 Ford F250 6.7L
Stock
Is your MAF Period working on the log? If so, you can check you period against the #/min to see if it's close.
Coyote uses Period in place of AD counts for 3vs.
And dyno's lie.
The car I used to have showed 86#/min on a M6. It made 672 at the wheels on a Dynojet.(In very cold 30* air)
Last edited by txcharlie; 06-25-2015 at 03:34 PM.
2013 Mustang 5.0 A6
Procharger P1SC1 STGII w/4" pulley = 10lbs
DW 95lb Injectors
Lethal Performance O/R X-PIPE
Borla S-Type
-----------------------------------------------------
2016 Ford F250 6.7L
Stock