AutoTap checklist (Ver.5)
Thread Starter
Staging Lane
Joined: May 2002
Posts: 57
Likes: 0
From: Dover, DE
AutoTap checklist (Ver.5) ****AutoTap Tuning Checklist (Rev.5)****
(With MAFT, & with out LS1 Edit)
Cruise/Base setting:
Monitor these parameters:
1. Fuel Trim Cell
2. Engine Speed
3. KR
4. LTFT B1S1
5. STFT B1
6. I.A.T.
7. TPS Angle
Readings from these parameters:
1. Fuel Trim Cell: Average only cells 6-14 for idle. Make sure you’re in cells 6-14 before logging. If not all recorded data is useless for this specific tune.
2. Engine Speed: Engine load
3. KR: As close to 0 as possible.
4. LTFT B1S1: Close to 0 as possible & preferably on the lean (positive) side of 0. (Use cells 6-14 to average)
5. STFT B1: Close to 0 as possible. (Use cells 6-14 to average) (When STFT is rich, this indicates a negative number. When STFT is lean, this indicates a number greater than 0. If STFT is rich/lean compensate by adjusting
the opposite way.)
6. I.A.T.: Temperature of incoming air.
7. TPS Angle: Percentage of throttle position.
Note: Turn A/C & stereo off & all accessories, etc. Do your tuning for idle on the same road, same distance (around 10 miles) every time. You don’t have to log LTFT B2S1 if it previously reads the same as B1S1. Same goes for STFT B2. This just gives a little better refresh rate for you.
WOT setting:
Monitor these parameters:
1. Fuel Trim Cell
2. Engine Speed
3. KR
4. MAF Airflow Rate
5. TPS angle
6. Ignition Timing advance
7. O2 sensor B1S1 volts
8. Injector Pulse Width Avg. B1
9. Delivered torque parameters (PID)
Readings from these parameters:
1. Fuel Trim Cell: 15 or 22 is WOT.
2. Engine Speed: Engine load.
3. KR: As close to 0 as possible at max timing advance.
4. MAF Airflow Rate: 30lb/min airflow at WOT.
5. TPS angle: At 80% or greater is WOT.
6. Ignition Timing Advance: 0 KR at max timing advance & timing around 28deg.
7. O2 sensor B1S1 volts: Average .89(Lean) - .91(Rich) indicated by Fuel Trim Cell 22 & TPS angle at 100%. (.89 being ideal for performance.)
8. Injector Pulse Width Avg. B1: Anything 18ms or higher, you need bigger injectors or you are too rich. (18ms is at 80% duty cycle)
9. Delivered Torque Parameters (PID): Negative #’s mean your letting off the gas or Tq management kicked-in. The higher positive #’s the better.
Note: Turn A/C & stereo off & all accessories, etc. You should log around 7K cycles for runs in Excel to have enough recorded parameters. You don’t have to log O2 sensor B2S1 if it previously reads the same as B1S1. This just gives a little better refresh rate for you.
Last words: Drive for at least one hour before making next log. The PCM goes by time not miles to relearn & idle won’t cut it, cruise! Your I.A.T. should equal outside ambient temperature at 30mph or above. If you’re worried about logging too many parameters at the same time, don’t! You can adjust some parameters to only log every so often, & if you get enough cycles in on each log, you will have plenty of numbers for averaging anyway. Last, remember that all averages are just a good starting point, and every car is different, so see what works best with yours. Fuel Trim Cell breakdown: Cells 0-5 & 21 are Non-loads, 6-14 are part throttle, 15 & 22 are WOT, 17-20 are Idle/Cruise. I want to also mention that you should keep an eye on KR, Timing Advance & Del. Tq. to determine if tuning changes were good or bad for performance rather then using a hard rule of what function values should be. Keep in mind, the richer you lie to the PCM via MAFT, the less airflow PCM thinks is flowing, which lowers Tq. & WOT timing. The less airflow reduces line pressure for A4 . A larger injector would allow to lie, to go leaner & gain more than lying about being richer.
(With MAFT, & with out LS1 Edit)
Cruise/Base setting:
Monitor these parameters:
1. Fuel Trim Cell
2. Engine Speed
3. KR
4. LTFT B1S1
5. STFT B1
6. I.A.T.
7. TPS Angle
Readings from these parameters:
1. Fuel Trim Cell: Average only cells 6-14 for idle. Make sure you’re in cells 6-14 before logging. If not all recorded data is useless for this specific tune.
2. Engine Speed: Engine load
3. KR: As close to 0 as possible.
4. LTFT B1S1: Close to 0 as possible & preferably on the lean (positive) side of 0. (Use cells 6-14 to average)
5. STFT B1: Close to 0 as possible. (Use cells 6-14 to average) (When STFT is rich, this indicates a negative number. When STFT is lean, this indicates a number greater than 0. If STFT is rich/lean compensate by adjusting
the opposite way.)
6. I.A.T.: Temperature of incoming air.
7. TPS Angle: Percentage of throttle position.
Note: Turn A/C & stereo off & all accessories, etc. Do your tuning for idle on the same road, same distance (around 10 miles) every time. You don’t have to log LTFT B2S1 if it previously reads the same as B1S1. Same goes for STFT B2. This just gives a little better refresh rate for you.
WOT setting:
Monitor these parameters:
1. Fuel Trim Cell
2. Engine Speed
3. KR
4. MAF Airflow Rate
5. TPS angle
6. Ignition Timing advance
7. O2 sensor B1S1 volts
8. Injector Pulse Width Avg. B1
9. Delivered torque parameters (PID)
Readings from these parameters:
1. Fuel Trim Cell: 15 or 22 is WOT.
2. Engine Speed: Engine load.
3. KR: As close to 0 as possible at max timing advance.
4. MAF Airflow Rate: 30lb/min airflow at WOT.
5. TPS angle: At 80% or greater is WOT.
6. Ignition Timing Advance: 0 KR at max timing advance & timing around 28deg.
7. O2 sensor B1S1 volts: Average .89(Lean) - .91(Rich) indicated by Fuel Trim Cell 22 & TPS angle at 100%. (.89 being ideal for performance.)
8. Injector Pulse Width Avg. B1: Anything 18ms or higher, you need bigger injectors or you are too rich. (18ms is at 80% duty cycle)
9. Delivered Torque Parameters (PID): Negative #’s mean your letting off the gas or Tq management kicked-in. The higher positive #’s the better.
Note: Turn A/C & stereo off & all accessories, etc. You should log around 7K cycles for runs in Excel to have enough recorded parameters. You don’t have to log O2 sensor B2S1 if it previously reads the same as B1S1. This just gives a little better refresh rate for you.
Last words: Drive for at least one hour before making next log. The PCM goes by time not miles to relearn & idle won’t cut it, cruise! Your I.A.T. should equal outside ambient temperature at 30mph or above. If you’re worried about logging too many parameters at the same time, don’t! You can adjust some parameters to only log every so often, & if you get enough cycles in on each log, you will have plenty of numbers for averaging anyway. Last, remember that all averages are just a good starting point, and every car is different, so see what works best with yours. Fuel Trim Cell breakdown: Cells 0-5 & 21 are Non-loads, 6-14 are part throttle, 15 & 22 are WOT, 17-20 are Idle/Cruise. I want to also mention that you should keep an eye on KR, Timing Advance & Del. Tq. to determine if tuning changes were good or bad for performance rather then using a hard rule of what function values should be. Keep in mind, the richer you lie to the PCM via MAFT, the less airflow PCM thinks is flowing, which lowers Tq. & WOT timing. The less airflow reduces line pressure for A4 . A larger injector would allow to lie, to go leaner & gain more than lying about being richer.
Re: AutoTap checklist (Ver.5) How good are the items in this checklist as far as being the way to analyze the autotap data collected. I've seen a couple of ways to do this and it just makes it more confusing as to what data captured that you should actually use to analyze. Can someone comment on this?
Thread Starter
Staging Lane
Joined: May 2002
Posts: 57
Likes: 0
From: Dover, DE
Re: AutoTap checklist (Ver.5) They are pretty acurate. It will give a good tune using this 'Cheat sheet'. All feedback is welcome. I've been working on this for a while now. I believe I've worked out most of the bugs. Let me know what you think.
