VE Tune | Spark Tune | Transmission Tune | Minor Tweaks | Data Logging
Everybody says that you can’t eliminate the MAF from a 3800 v6 tune, I say you can, and that my car has run better on my VE tune than what it ever has on my MAF tune I modified with Hp tuners.
In order to make this work you are going to have to “cheat” a little. The biggest problem with a VE tune is that you max out the MAP on these cars somehow at 200% (which really isn’t possible, but for whatever reason on our PCM it is) Do Not Attempt this without a Wideband O2 Sensor
In order to have your car start referencing your VE tables as opposed to your MAF tables you will need to set your MAF to fail. In order to do this Go to the Engine Diagnostics tab > Airflow > MAF Sensor and set the MAF Fail High to 0 Hz. This will Force the Code P0103 and automatically fail the MAF. (To turn this code off go to the DTC’s tab and uncheck the code under SES Enable. By doing this you are still allowing the car to throw the code, but not letting it display on your dash as an illuminated light. If you turn off the code all-together then the MAF may not “fail”)
Alright, you’ve now successfully failed the MAF sensor reverting the car to a VE tune. There are issues you’ll have to deal with for spark tuning, I explain this in spark tuning
Next thing to take care of before we start scanning is Open/Closed Loop enable. We are going to want to run the car in Open Loop so set the Coolant Temp to the highest setting that you can, in my case it is 140*C
Next we need to protect the motor. Go into your Fuel Tab > Power Enrich> Base AFR vs ECT and set everything to 11.0 AFR (maybe more depending on the mod’s you have. You’ll soon find out if you are too rich/too lean with this command) Don’t worry about how low you just set your Base AFR for when you enter Power Enrichment Mode, because while in PE mode you won’t actually hit those specific numbers as you will max out your VE table before this is possible and will be off by a “%”. This is why you are setting the car to ask for a richer condition than what you want, to make up for this percentage error. If you set the PE to what you actually want, you will run lean as you will likely be approximately 30% off your mark.
You are now going to go to the Add vs Rpm tables (under the same Tab you’re already under) and start scaling how you will be adding fuel.
This part is important, because without a MAF, your car will not look to scale the fuel and add more fuel for you, so you are going to manually input this information regarding when/how much fuel to add and have the car slowly step into full Power Enrichment mode.
I started my table at 3200rpm. Because I have a big stall converter/Cam combo I am asking for more fuel so my tables are at -1.151, however, depending on your mod’s I would maybe start with -0.500 (you probably do not have an extreme setup as I do). What this is telling the computer to do is to add another .5 of fuel to the 11.00 AFR at the given RPM. So in PE mode at 3200 rpm your car will now be asking for 10.5afr (remember, don’t worry about the fact that this sounds too rich right now)
Scale your table across all the way to 6400 rpm adding a little bit of fuel at each rpm interval.
*note that in my tables I added 0.200 at 2400 rpm at the 12.8 second mark. This was just to cover if I got stuck going up a long hill and was putting some stress on the motor, I didn’t want to chance getting knock*
Final thing that needs to be addressed before going out and getting some logs is your PE Enable TPS. Remember when I said you’re going to have your car slowly step into PE mode and that is why you were slowly scaling your “add vs rpm” table? Well this is why. Select your entire table from 2000rpm onwards and set it to 30% throttle (this can be adjusted later if you believe it is too low). The idea here is that prior to 30% throttle you will be commanding stoich (or the same number that you have under the General>General>Air Fuel Ratio tab)
Under 30% throttle this is what your car will command and strive to maintain. Above 30% throttle you car will begin commanding Power Enrichment. By scaling everything properly in your tune, your car will begin richening up with the more throttle you put in. Example, you are cruising at 14.7 AFR, as you roll into the throttle and hit 3200 rpm and 30% throttle you will be at 14.0afr, at 4000 rpm you’ll be at 13.7 and so on and so forth. Don’t worry if your first few scans are a little richer than this (I know you are commanding around 10afr) we are going to be seeing what the car is actually getting and making adjustments to your tune for the above mentioned.
Alright, time to go out and get some logs. Make sure you have a VE wideband AFR error table (similar to your MAF error table, except for VE)
If not, you can download my tune configuration below and use mine. Note that you’ll probably want to re-adjust the wideband error to match your wideband and not my AEM one.
Fire the car up and reset the fuel trims, go for a short drive with low part throttle. Continue on to data logging