what tuning needs to be done for a custom intake? is it just a maf cal or is there more to it than that? 04 f150 4.6 2v new body style.
thanks.
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what tuning needs to be done for a custom intake? is it just a maf cal or is there more to it than that? 04 f150 4.6 2v new body style.
thanks.
Any increase and airflow will require changes to the fuel and spark tables as well as the MAF transfer table.
the maf table wont correct small fuel changes automatically? i wont be trying to max out the performance of it immediately, just want to get it running safely and keep fuel trims in check.
The reason you want to correct it is because any guesswork or compensation on the part of the PCM leads to drivability issue's, this is my understanding of it at least.You want the PCM to have to do as little guesswork as possible.
i guess that makes sense. is there a write up on how to do all of this with fords?
anyone?
First you want to disable your LTFT's or long term fuel trims, basically, you don't want to make fueling changes while the car is trying to learn and make its own fueling changes, otherwise you will end up chasing your own tail. You will have no idea what is affecting the cars behaivor, your tune changes, or the car attempting to solve the fueling problem on its own. Also make sure the car is up to temp before datalogging, there are several tables that will affect fueling on cold start, again, you won't be sure what is affecting the cars behaivor, you or some startup enrich table. Disabling LTFT's is application specific, I don't know how to do that specifically with your truck.
Basically all you're doing is correcting the MAF transfer function or the amount of airflow the MAF reads for a given voltage. If your engine can't accurately model the airflow going into it, then it cant achieve its desired Air Fuel Ratio, this means that there will be an error in fueling. This error is reflected in your short term fuel trims, which is the measured Air Fuel Ratio divided by the commanded Air Fuel Ratio. To correct this, you need to multiply the MAF airflow value in a particular cell by the STFT in the same cell. So a STFT of 1.02 would be a 2% correction. You don't want to apply the full correction, just half of it, make small changes and see how the car responds. Do not half the STFT reading, half the percent correction( in the above example instead of applying a full 1.02 correction, multiply by 1.01 to reflect a 1% change, not .51, which would reflect a 49% change). Repeat this process, record your STFT, apply your correction until your fueling error is under 3% at least, the lower the better, 1-2% would be ideal. You must correct your entire MAF curve, from idle to WOT, watching your STFT, making sure it isn't too far off. I doubt your truck has wideband 02 sensors so you can't measure a wide range of Air Fuel readings, so you may not be able to tune for WOT, I am not entirely sure. I'm away from a computer, so this is the best I can do for now. Luckily, there is plenty of info on this process. I will try to answer any of your other questions, a lot of this is application specific, your F150 is a lot different from my coyote, but the process is the same, best of luck. I was waiting hoping that someone that had experience with your specific application would have chimed in, but that didn't happen. I am a real noob here and would definitely not consider myself a tuner, I am still in the learning phase, thought I might as well share what I knew so far on the topic.
Here's a good thread to read:
http://www.hptuners.com/forum/showth...ote-MAF-tuning
As well as another one: http://www.silveradoss.com/forums/to...the-maf-sensor
thanks for the help. is the scanner up to the task yet? last time i tried it was slow and missing a lot of parameters.
I don't know honestly, it will be a while before I even tune my project, just trying to learn as much as I can right now. I haven't had a need to mess with it at this point. Hopefully someone else will let us know.