10-21-2020, 08:47 AM | #15 | |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,800
|
Quote:
__________________
2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
|
10-21-2020, 03:10 PM | #16 |
Drives: firebird Join Date: Jan 2010
Location: valdosta, georgia
Posts: 155
|
Pretty sure i did that too. Does the stft still work if thats disabled? Ltft are off but stft still correcting
|
10-23-2020, 11:00 AM | #17 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,800
|
The only time fuel trims are not used is when the ECU is in open loop. Closed loop fueling relies on MAF and o2 data to trim the fuel to achieve stoich.
__________________
2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
10-24-2020, 04:44 PM | #18 |
Drives: firebird Join Date: Jan 2010
Location: valdosta, georgia
Posts: 155
|
Then why do you disable O2 sensors when tuning maf?
|
10-24-2020, 06:38 PM | #19 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,800
|
I don't disable o2's for closed loop maf tuning. I log maf vs LT fuel trim for part throttle and log Maf vs wideband error for PE tuning then adjust the maf accordingly.
__________________
2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
10-24-2020, 08:54 PM | #20 |
Drives: 2017 Camaro 2SS A8 Join Date: Aug 2018
Location: Petersham MA
Posts: 4,760
|
Agreed, same here.
__________________
2017 Chevy Camaro 2SS A8 Whipple 3.0, Mast Black Label heads, Fore triple in-tank pumps, 112mm TB, LPE +52% injectors, LPE BB HPFP, 15” conversion 1059 WHP/944 WTQ, 9.48@150
|
10-25-2020, 04:02 AM | #21 |
Drives: 6th gen Join Date: Aug 2013
Location: US
Posts: 3,678
|
X3
__________________
‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122
‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold) |
10-25-2020, 08:35 AM | #22 |
Drives: firebird Join Date: Jan 2010
Location: valdosta, georgia
Posts: 155
|
Now i am confused. If you use o2 sensors and ltft for tuning your maf then its not maf only, you are using the sensors to make adjustments. Then how do you know your mad is tuned properly if the sensors keep making fuel trim corrections
|
10-25-2020, 09:51 AM | #23 | |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,800
|
Quote:
When not in PE mode(closed loop),which is used for idle and part throttle conditions, The ECU still relies on the MAF and O2's for fueling control to achieve stoich via fuel trim adjustments. When you dial in the MAF there will be less fuel trim correction needed. Ideally you want to be between -5 and 0. If you are outside that window then you adjust the MAF until you get in that range in your part throttle cells. Now when you go WOT the ECU enters PE mode(open loop) and only references the MAF for fueling above the rpm you set the dynamic air flow cutoff. Most MAF only tunes disable Dynamic Airflow above 1000rpm. This is where you need to log a Maf error vs wideband afr histogram because o2's and fuel trims are not used for fuel correction. If you set dynamic airflow to let's say 6000rpm the ECU would reference both the VVE and MAF for fueling up to that rpm. If you force the ECU into SD mode(Speed Density), then it won't use the MAF at all and rely on VVE for all fuel correction. The issue with this(albeit a minor issue) is that when the weather changes your fueling will change, that is why GM uses MAF sensors because it can correct fueling for temperature and air density change in both Open and Closed loop. Hopefully that clears things up for you.
__________________
2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
|
10-25-2020, 12:22 PM | #24 |
Drives: firebird Join Date: Jan 2010
Location: valdosta, georgia
Posts: 155
|
Oh ok then i guess i need a bung welded in my exhaust? Cause i just took out a pre cat o2 and used my wideband in that spot. In that case i might need cat delete pipes cause there is no room for another o2 sensor in my 2017 ss. Probably why i was getting 22% stft on that bank
Last edited by pavetim; 10-25-2020 at 02:07 PM. |
10-26-2020, 08:51 AM | #25 |
Drives: firebird Join Date: Jan 2010
Location: valdosta, georgia
Posts: 155
|
I have room after the primary cats for a wideband but there is a big debate about that. I seen a guy on YouTube, australian guy forgot his channel but he said he has tested before the cat and after and the afr difference is so tiny it doesnt matter. Opinons?
|
10-26-2020, 09:00 AM | #26 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
Posts: 6,800
|
I was always told to keep the wideband in front of the cats but I have not tested that theory. I have a bung welded into one of my CA cat delete pipes. You could grab a set of delete pipes(two sets for sale right now in the classifieds) and have a bung welded in and bolt those in place of the factory cats. This will make your exhaust louder.
__________________
2016 NFG 1SS A8
Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
10-26-2020, 12:35 PM | #27 |
Drives: firebird Join Date: Jan 2010
Location: valdosta, georgia
Posts: 155
|
Then would i have to delete the secondary cats too, maybe taking too much heat since primaries do most of the work?
|
10-26-2020, 01:59 PM | #28 | |
Drives: 2017 Camaro 2SS A8 Join Date: Aug 2018
Location: Petersham MA
Posts: 4,760
|
Quote:
+1 on putting the wideband O2 before the cat too.
__________________
2017 Chevy Camaro 2SS A8 Whipple 3.0, Mast Black Label heads, Fore triple in-tank pumps, 112mm TB, LPE +52% injectors, LPE BB HPFP, 15” conversion 1059 WHP/944 WTQ, 9.48@150
|
|
|
|
Post Reply
|
|
|