v3mafadjcombft
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v3mafadjcombft [2009/01/01 09:40] twdorris |
v3mafadjcombft [2009/08/05 05:58] twdorris |
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| - | ====== MAF Adj: CombinedFT ====== | + | ====== MAFComp Adjust (CombinedFT) ====== |
| - | The **MAF Adj: CombinedFT** menu item is one of several tools you can use to help "dial in" your airflow settings. This particular item maps out and averages [[v3combinedft|CombinedFT]] over a range of closed loop driving conditions to produce a set of adjustments to the current MAF compensation table. It's basically letting the ECU track how much adjustment it needs under various conditions and then moves that adjustment into the MAF compensation table. | + | The **MAFComp Adjust (CombinedFT)** menu item is one of several tools you can use to help "dial in" your airflow settings. This particular item maps out and averages [[v3combinedft|CombinedFT]] over a range of closed loop driving conditions to produce a set of adjustments to the current MAF compensation table. It's basically letting the ECU track how much adjustment it needs under various conditions and then moves that adjustment into the MAF compensation table. |
| This function probably helps most with a GM MAF setup run straight to the ECU using ECMLink's GM MAF integration option. That particular configuration produces a pretty large number of MAF sample points for fairly typical driving conditions (easily ranging from 500hz to 2000hz for simple idle and cruise conditions). So having a tool which helps establish a decent starting point can be very handy here. | This function probably helps most with a GM MAF setup run straight to the ECU using ECMLink's GM MAF integration option. That particular configuration produces a pretty large number of MAF sample points for fairly typical driving conditions (easily ranging from 500hz to 2000hz for simple idle and cruise conditions). So having a tool which helps establish a decent starting point can be very handy here. | ||
| + | Although this function probably helps a direct GM MAF setup more, it can still be useful with other configurations too. | ||
| - | + | ====== STEP 1: Check Your Fuel Settings ====== | |
| - | ===== Initial requirements ===== | + | |
| You absolutely MUST make sure your fuel settings are already appropriate for your injector size, fuel type and base fuel pressure. If there is any deviation here, then the adjustments to airflow suggested by this function will simply include those fuel corrections as well! This can create a really confusing configuration if you aren't careful. So please review your [[baseinjectordata|global fuel and deadtime settings]] first to make sure they are at least somewhat reasonable for your setup. | You absolutely MUST make sure your fuel settings are already appropriate for your injector size, fuel type and base fuel pressure. If there is any deviation here, then the adjustments to airflow suggested by this function will simply include those fuel corrections as well! This can create a really confusing configuration if you aren't careful. So please review your [[baseinjectordata|global fuel and deadtime settings]] first to make sure they are at least somewhat reasonable for your setup. | ||
| + | |||
| + | ====== STEP 2: Check For Closed Loop Operation ====== | ||
| Make sure the car is able to run in closed loop mode. Look for a cycling FrontO2 sensor and a "1" in the ClosedLoop log item. It doesn't have to be running with fuel trims near 0% (that's the purpose of using this function after all). But it does need to at least cycle in closed loop mode on its own. If it does not, you need to make some manual adjustments first to at least get it running in closed loop. | Make sure the car is able to run in closed loop mode. Look for a cycling FrontO2 sensor and a "1" in the ClosedLoop log item. It doesn't have to be running with fuel trims near 0% (that's the purpose of using this function after all). But it does need to at least cycle in closed loop mode on its own. If it does not, you need to make some manual adjustments first to at least get it running in closed loop. | ||
| A good understanding of [[v3combinedft|CombinedFT]] and [[fueltrimupdatepoints|fuel trim in general]] will help a lot with your understanding of this function. | A good understanding of [[v3combinedft|CombinedFT]] and [[fueltrimupdatepoints|fuel trim in general]] will help a lot with your understanding of this function. | ||
| - | Add the following log items to your captured values: CombinedFT, MAFRaw and ClosedLoop | ||
| - | Make sure the engine is at full operating temperatures. You don't want to mess with coolant based variations at this point. You want to stabilize everything you can first and then adjust based on the one variable left (presumably airflow variation). | + | ====== STEP 3: Data Capture ====== |
| + | Add the following log items to your captured values (F10): CombinedFT, MAFRaw and ClosedLoop | ||
| - | ===== Basic Usage ===== | + | Make sure the engine is at full operating temperature. You don't want to mess with coolant based variations at this point. You want to stabilize everything you can first and then adjust based on the one variable left (presumably airflow variation). |
| - | Once you're satisfied that the requirements above have been met, you're ready to grab a datalog. Let the car idle for about a minute. Then go drive. Try to keep the car in closed loop mode as much as possible (more on that in the advanced section). When you're done, you can click on the "MAF Adj: CombinedFT" menu item to see what the application comes up with. Review this, smooth the points as you'd like, extend the points to cover areas where you did not collect data and then hit "Save to ECU" when you're done. | + | Once you're satisfied that the requirements above have been met, you're ready to grab a datalog. Let the car idle for about a minute. Then go drive. Try to keep the car in closed loop mode as much as possible (more on that in the advanced section). |
| - | **NOTE:** You're basically changing the very data long term fuel trim was previously based on. So if you're making fairly large changes to MAF compensation, you should consider resetting the long term fuel trim values using the "Reset fuel trims" menu item in the ECU menu. | ||
| + | ====== STEP 4: Run the Adjustment Tool ====== | ||
| + | When you're done, stop the log and click on the **MAFComp Adjust (CombinedFT)** menu item (right click in the graph window to get this menu item) to see what the application comes up with. Review this, smooth the points as you'd like, extend the points to cover areas where you did not collect data and then hit "Save to ECU" when you're done. | ||
| + | |||
| + | **NOTE:** You're basically changing the very data long term fuel trim was previously based on. So if you're making fairly large changes to MAF compensation, you should consider resetting the long term fuel trim values using the "Reset fuel trims" menu item in the ECU menu. | ||
| - | ===== Advanced Usage ===== | + | ====== Advanced Usage ====== |
| Because this function operates only during closed loop mode, it's handy to try to extend closed loop mode as much as possible so that you get a wider range of data in your logs. This will produce a larger number of auto-adjustments to the airflow curve for you. | Because this function operates only during closed loop mode, it's handy to try to extend closed loop mode as much as possible so that you get a wider range of data in your logs. This will produce a larger number of auto-adjustments to the airflow curve for you. | ||
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| - | ===== Sample Calibration ===== | + | ====== Sample Calibration ====== |
| I'll walk through a sample calibration of my own car below. This is a 1995 AWD Talon with 850 injectors running E85 and a GM 3" MAF connected to the ECU. The MAF is installed just before the throttle body using upper IC piping that has flared 3" ends as shown below. | I'll walk through a sample calibration of my own car below. This is a 1995 AWD Talon with 850 injectors running E85 and a GM 3" MAF connected to the ECU. The MAF is installed just before the throttle body using upper IC piping that has flared 3" ends as shown below. | ||
| - | << insert picture when I finally remember to bring the //@$!%$!$// memory card in >> | + | {{ http://www.ecmtuning.com/images/forums/gmmafinstall.jpg }} |
| Download the datalog below to review the initial drive cycle (20 minutes or so) and setup. The things to note include the global fuel setting and the MAF compensation. | Download the datalog below to review the initial drive cycle (20 minutes or so) and setup. The things to note include the global fuel setting and the MAF compensation. | ||
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| {{ http://www.ecmtuning.com/images/forums/mafadjcombft/resultsfinal.png }} | {{ http://www.ecmtuning.com/images/forums/mafadjcombft/resultsfinal.png }} | ||
| - | This is my new, final configuration. I'll do an "ECU->Reset fuel trims" next and go drive. Everything should line up much better now. | + | This is my new, final configuration. To get that centered nicely, I'll click the "Change..." button next to "Global scalar" field and then click "Auto Adj" on the dialog that pops up. The application will center the current set of adjustments for me and produce an appropriate global scalar value. I'll then do an "ECU->Reset fuel trims" and go drive. Everything should line up much better now. |
v3mafadjcombft.txt · Last modified: 2024/03/15 11:16 (external edit)
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