I've got the idle working but now I'm trying to reduce the sTFT, what tab should I be using ? I've got the idle squared away but after configuring the histogram I realized the changes I need to make. Any suggestions would be helpful , before you jump me I tried to google it but I get nothing ...
07 ZO6 which heads and a mild cam with 2 deg of overlap
07 Z06, 65 V-8 5 speed Mustang 'vert,Subaru
outback, VFR800
Stft doesn't use a table, you tune your ve table until your stft's are close as possible to 0. 0 is not possible but most try for +/- 5.
They trim fuel by either adding or taking away to make the motor run at whatevrr you have your stoich afr set to. Usually 14.7ish on gas, that is what it is from the factory.
After you add or take away fuel on the ve table and flash the new tune in you need to reset your fuel trims in the scanner then see where your at from there. You'll either be good or you'll need to go back in and make more adjustments until the stft's arent making big adjustments like +/- 20 or something
Do you have the MAF HI/LOW and LT/ST pids in the primary table and do you have histograms configured for MAF hi/lo vs STFT/LTFT and VE vs ST/LTFTs? If so, you can do forced closed loop mode MAF and VE adjustments using the narrowband O2. Your PCM does not have a VE table, but you can still do 'virtual VE table' tuning by fuel trims in closed loop with the EQ_VE program (search for virtual VE table program.)
When I do MAF/VE tuning with the narrowband, I have a set of changes I make to the tune first, which forces closed look, disables DFCO, disables PE and reduces timing to keep piston temps down, then I will do the VE part with the MAF tables zeroed out and in forced SD mode, then I re-enable MAF and finish the trims on the MAF.
I posted a little write up on how to do it with fuel trims a while back (like 6 years ago) but can't seem to find the link now. I could probably find the word version of it if you want.
I cant seem to get the grasp of the sd tuning. ALL the guides are dated and not much can be found on 2.24. I cant seem to find the secondary ve table and if I am supposed to make fueling changes to the Main ve table it only pastes to the top 2 rows. I need help please.
Post a tune, log, something. It's not that hard. You don't adjust STFT's directly. They are how the computer fixes screw ups in the VE table on the fly. And to be more specific, by default the car is using long AND short term fuel trims. You need to be logging and using both (or disabling long term) to make proper corrections.Originally Posted by goatnipples2002
What are you reading about secondary VE table? I don't think the gen 4's have that. I think that's a gen 3 thing.
The idea is to log fuel trims vs. the primary VE table. They are your correction factors. Apply correction factors to VE table. Write new file back to car..
Rinse, repeat
I've noticed that on gen 4's, after a new calibration is written to them, it seems like they need a good 30 minute drive before the fuel trims settle down.
Last edited by schpenxel; 02-13-2015 at 08:53 PM.
Post your file, The principles are the same from the old info thats out there.
You log you STFT vs what ever type of tune your running.
You need to learn the basic like setting up histograms and etc first .
For example STFT vs VE if in speed density, or STFT vs MAF if your using the maf, but you need to set the maf to enable at 500 rpms and dissable at 400
The part im lost on, is you dont seem to mention using the bluecat software or the new beta version of HP tuners, yet you have a 07 ecu which doesnt provide a ve table.
Logging STFT's won't be worth much if he doesn't disable LTFT's first.
Bottom line.. post a tune/log and people will try to help point you in the right direction
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