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This is a how to guide on how to properly dial in air to fuel ratio.
*EDIT* If anything on this guide isn't making complete sense to you, Do some reading at hptuners.com/forums. This is basically a spoon feeding guide and involves the basics on how to tune your VE/MAF/AFR - what makes or breaks a good tune.
I am not liable if you blow up your car. *EDIT*
*EDIT 2* Pics added. Sorry pics are so small, right click save as. *EDIT*
1. Disable dfco
2. Disable LTFT
3. Disable STFT
4. Address the open loop table
5. Disable COT & Disable piston protection
6. Dialing in your power enrich table
1. Disable dfco
-to disable DFCO just set the enable temp. to 300 or higher, you don't need to change the other dfco settings. (unless you really want to!)
![]()
2. Disable LTFT
-to disable LTFT do the same thing, set the enable (min.) temp. to 300 or higher.
![]()
3. Disable STFT
-you should also disable STFT by modifying the 2 tables under the closed loop heading.
-ECT vs Startup ECT - set the whole table to 300
-O2 readiness ECT - set the whole table to 400
![]()
4. Address the open loop table
Then there are 4 tables you need to modify under the 'open loop' heading because they can apply a factor to the fueling calcs.
-Gas(Gear) set the whole table to 1.00
-Gas(P/N) set the whole table to 1.00
-IVT Gain set the whole table to 1.00
-EQ Ratio Min set the whole table to 1.00
![]()
5. Disable COT & Disable piston protection
While you are calibrating your air and fuel you should also disable Piston Protection and preferably COT too because they can also complicate the fueling calcs.
- Disable Piston Protection by setting it to 8192
- Disable COT by zeroing out the 2 adder fields, and setting the temp. thresholds to 7400.
(Note that disabling COT can cause damage to your Catalytic converter if you have one!!! because it can be left to overheat!!)
![]()
![]()
6. Dialing in your power enrich table
- To dial in your power enrich table, or AFR for wide open throttle, Simply divide stioch AFR (14.689 or 14.7) By the AFR you would like to see.
For example in this case well say 11.8.
14.689/11.8 = 1.2448 (usually the first 5 numbers are enough to use)
Now place the 1.2448 in the power enrich tab > eq ratio vs rpm table. Do so across the entire board making your PE curve as flat as possible.
![]()
As far as your timing tables go, I would just use the gm factory timing tables as starting points, just to keep things safe.
Now, drive your car around as smoothly as possible without any sudden throttle changes. You want to be as dead on as possible. That will help dial in your cruising mafs ranges. To tune for WOT simply mash the gas.
Use your hpt scanner to read maf error %. Or VE error %
Get the results from the scanner, after you have at least 30 hits on every cell you want to adjust for. Copy the results from the scanner, and paste them to your tune's MAF freq table under the airflow tab. Or the VE table located in the same tab. Use hand smoothing when possible. REFRAIN from using the auto smooth option for all that is holy.
Initially, you would like the maf or VE error % to be as close to 0 as possible. -4 or +4 are not close enough. Make a valid attempt to get it into the 1s at the very least. Also, Its always better to be in the negatives then the positives. So shoot for -1 if possible.
Thank you Omega for submitting this:
Thought I'd add;
To tune the VE, set Engine Diagnostics -> Airflow -> MAF Sensor -> MAF Fail High to 0Hz to disable the MAF
You'll need to copy the high octane table to the low table
To tune MAF, set Engine -> Airflow -> Dynamic Airflow -> High Disable -> to under 500RPM
and Engine -> Airflow -> Dynamic Airflow -> High re-enable -> to 100RPM less than the disable setting to disable the VE.
Thats all there is to it. These same settings should be used whether you are maf tuning or ve tuning. The only difference is whether the maf is enabled or disabled.
Huge thanks to everyone who has helped me with VE and MAF tuning when I didnt know any better. It may have been some time in the past, but you are not forgotten. :bluecap:
*EDIT* If anything on this guide isn't making complete sense to you, Do some reading at hptuners.com/forums. This is basically a spoon feeding guide and involves the basics on how to tune your VE/MAF/AFR - what makes or breaks a good tune.
I am not liable if you blow up your car. *EDIT*
*EDIT 2* Pics added. Sorry pics are so small, right click save as. *EDIT*
1. Disable dfco
2. Disable LTFT
3. Disable STFT
4. Address the open loop table
5. Disable COT & Disable piston protection
6. Dialing in your power enrich table
1. Disable dfco
-to disable DFCO just set the enable temp. to 300 or higher, you don't need to change the other dfco settings. (unless you really want to!)
2. Disable LTFT
-to disable LTFT do the same thing, set the enable (min.) temp. to 300 or higher.
3. Disable STFT
-you should also disable STFT by modifying the 2 tables under the closed loop heading.
-ECT vs Startup ECT - set the whole table to 300
-O2 readiness ECT - set the whole table to 400
4. Address the open loop table
Then there are 4 tables you need to modify under the 'open loop' heading because they can apply a factor to the fueling calcs.
-Gas(Gear) set the whole table to 1.00
-Gas(P/N) set the whole table to 1.00
-IVT Gain set the whole table to 1.00
-EQ Ratio Min set the whole table to 1.00
5. Disable COT & Disable piston protection
While you are calibrating your air and fuel you should also disable Piston Protection and preferably COT too because they can also complicate the fueling calcs.
- Disable Piston Protection by setting it to 8192
- Disable COT by zeroing out the 2 adder fields, and setting the temp. thresholds to 7400.
(Note that disabling COT can cause damage to your Catalytic converter if you have one!!! because it can be left to overheat!!)
6. Dialing in your power enrich table
- To dial in your power enrich table, or AFR for wide open throttle, Simply divide stioch AFR (14.689 or 14.7) By the AFR you would like to see.
For example in this case well say 11.8.
14.689/11.8 = 1.2448 (usually the first 5 numbers are enough to use)
Now place the 1.2448 in the power enrich tab > eq ratio vs rpm table. Do so across the entire board making your PE curve as flat as possible.
As far as your timing tables go, I would just use the gm factory timing tables as starting points, just to keep things safe.
Now, drive your car around as smoothly as possible without any sudden throttle changes. You want to be as dead on as possible. That will help dial in your cruising mafs ranges. To tune for WOT simply mash the gas.
Use your hpt scanner to read maf error %. Or VE error %
Get the results from the scanner, after you have at least 30 hits on every cell you want to adjust for. Copy the results from the scanner, and paste them to your tune's MAF freq table under the airflow tab. Or the VE table located in the same tab. Use hand smoothing when possible. REFRAIN from using the auto smooth option for all that is holy.
Initially, you would like the maf or VE error % to be as close to 0 as possible. -4 or +4 are not close enough. Make a valid attempt to get it into the 1s at the very least. Also, Its always better to be in the negatives then the positives. So shoot for -1 if possible.
Thank you Omega for submitting this:
Thought I'd add;
To tune the VE, set Engine Diagnostics -> Airflow -> MAF Sensor -> MAF Fail High to 0Hz to disable the MAF
You'll need to copy the high octane table to the low table
To tune MAF, set Engine -> Airflow -> Dynamic Airflow -> High Disable -> to under 500RPM
and Engine -> Airflow -> Dynamic Airflow -> High re-enable -> to 100RPM less than the disable setting to disable the VE.
Thats all there is to it. These same settings should be used whether you are maf tuning or ve tuning. The only difference is whether the maf is enabled or disabled.
Huge thanks to everyone who has helped me with VE and MAF tuning when I didnt know any better. It may have been some time in the past, but you are not forgotten. :bluecap:
