MAFT Version 2.0+ Tuning Guide
MAF Translator Tuning Guide
MAFT Version 2.00+
Please note that this guide is for the tuning of version 2.00+ ONLY! While the same principles will apply for the earlier models, the switch settings and some of the system architecture is different, so the exact directions cannot be followed for version 1.37 and down.
The MAF Translator is a tool that allows you to use the less restrictive GM MAF in place of the stock DSM MAF. Due to the nature of the GM’s hotwire MAF, you can either put the sensor in the stock location, or you can mount it before the throttle body in the upper intercooler pipe.
The setup instructions are included with the product, so this guide won’t touch that topic.
Before you even start the car for the first time, you need to set the MAFT up. Set the mode 1 and 2 switches to the proper locations for the MAF that you are using (see table).
Set the mode 3 and 4 switches to off for now, until the car has a good base tune.
Using the following table, set the base knob and aux knob for whatever size injectors you are using:
This is not an acceptable long-term solution, but it will be good enough for the car to start and run. If you’re running injectors that are larger than stock, you probably will want to richen up the idle setting a little bit too, to compensate for the higher deadtime. 2-3 clicks is usually a good place to start.
IMPORTANT: Note that the base knob gets leaner as you go clockwise, and the rest of the knobs go richer in a clockwise direction, and leaner in a counterclockwise direction.
Base Knob Tuning
Before you go driving to set the base knob, you may want to reset the ECU, especially if the car is a 1g. This will reset the fuel trims all to 100% (1g) or 0% (2g), and will simplify tuning.
The base settings apply as follows:
Start the car, let it warm up, and go for a drive. You want a nice steady state cruise, 50-70 mph or so is pretty good. Watch the O2 Trim (1g) or STFT (2g), as well as the hi fuel trim (1g) or the LTFT (2g). You want to get both of these as close to zero correction as possible, which means 100% for a 1g and 0% for a 2g. If these read too high, you need to richen the base knob (counterclockwise), and if they read too low you need to lean it out (clockwise). Keep doing this, until the fuel trims are hanging out near no adjustment. On a 1g, you want the O2 trim to cycle around 100% with the hi trim around 100, and on a 2g you want to try to get within a couple percent.
Mid and WOT Tuning
Once the base is set up, then it is time to work the mid and WOT settings. Setting up the mid knob can be a bit difficult, but there are a couple tricks to make it a bit easier. First of all, the mid area will become active as you roll onto the throttle from cruise, until you build a couple psi of boost (approximately 180 to 500Hz of airflow). Roll onto the throttle like this and keep an eye on the STFT/O2 trim, and watch where it goes until the car goes into open loop (when the trim will drop back to 0%/100%). If it rises, then the car is leaning out a little, and if it goes down, then the car is going rich. Adjust accordingly, if possible. On 1g’s, you can also watch for knock.
From there, you go to WOT tuning. The basic premises behind this are simple, but tuning well takes a lot of practice. The basic idea is you want to keep the car from knocking at all, which allows you to run the most timing (and is also safest for your engine, of course). The hard part about this is that timing is related to airflow; the less airflow the ECU sees (because of negative correction on the MAFT), the higher the timing advance will be. You need to find a good mix of boost, timing, and fuel.
Make a full throttle pull through as much of the RPM range as you possibly can. 1g’s are easy, because you can just look for knock and then richen the MAFT up if you see any moderate amount. On a 2g, it’s a little more difficult. You have to base the tuning off the total timing retard. If the timing seems low, you might be getting knock, so try richening up the WOT on click. If the timing goes up, you’re going in the right direction. If it goes down more, then it’s probably low because the airflow is so high, and you can try leaning it out.
WOT Fine Tuning
Note: Do not worry about fine tuning the WOT corrections if you are not confident in your tuning abilities. The car will run fine with only the 4 basic knobs set up.
Also, do not switch to WOT tuning mode, until you have driven around for a few days to get the feel for the basic mode, and to make sure that the fuel trims are in line.
If you are sure both of these two conditions are satisfied, then proceed.
The WOT fine tuning mode adjust the WOT fueling based on 4 rpm breakpoints, as shown below:
It's best to switch from base tuning mode to WOT tuning mode with the ignition off, to avoid any software problems. Also, keep in mind that the MAFT will save your base mode settings 10 seconds AFTER you make any change, so just be sure to give the car at least ten seconds between a base mode change and turning it off. Before switching modes, make sure to record your base settings in case you want to go back and change them later. Switch the mode 4 switch to the “on” position, and zero out all of the knobs. In this mode, the tuning is in 2% increments, and all the points are interpolated.
Using the same methodology as you did for the WOT base knob, tune the four rpm points. Watch the logger and/or wideband O2 meter, and at each point make a distinction as to whether you want to go leaner (and consequently add timing), richer (and take timing out) or stay the same.
I've been sitting on that for a little while, waiting for 2.0 to be public. Now that it's out, hopefully that will help someone.
When I can get my hands on a set of finalized instructions, I can change anything that needs it.
Also, if any of you guys have suggestions, tips, or problems, please let me know!
For a "chipped" computer compensating for larger injectors, would you just set the base and aux to whatever the stock injectors were?
i'm thinking about that too, except not with "fixed" a/f ratios. I have DSMLink. What I figured would work would be to set the MAFT like you normally would, with the DSMLink fuel adjustments all set to zero. Then pretty much just fine tune the air/fuel with the DSMlink where it is needed across the RPM range, and not even use the Mode 4 on the MAFT. does that sound right?
as for the DSM chips that you are talking about, I would do what you said and set the MAFT up like you have stock injectors, and then follow the instructions like you normally would. Then you are using the chip to have the base setting to get the car running pretty good, and useing the MAFT for fine tuning it. I think you'll need a logger of some sort if you don't have one though.
I know version 2 and version 1's directions are different, but does this apply to versio 1.x as well? Or has version 2 changed how it handles mid throttle settings?
With regard to chips and DSMLink:
If you have a chip or DSMLink which is allowing you to fully compensate for the injector size, let that do it's job. Those systems are set up to work with a stock MAF, so leave the MAFT such that it emulates your stock MAF. In order to do this, set it for your generation car, and stock injectors.
Then, do all your tuning in DSMLink, or do injector compensation on the chip and tune with the fuel and timing maps if the can. If not, then you can use the WOT switches on the MAFT.
Boosted: Yes, that section applies to all versions.
Can we get a lb/min for "180 to 500Hz " or a formula to convert that for the 2G?
Hopefully we can get Mike or Bob in here for that one. I don't own a 2g, so I don't know what the MAF vs. Airflow conversion is.
However, if someone on here has a 2g with a a SAFC and a logger, can you go make a pass and tell us the peak Hz and the peak lb/min? Please? That would give me the information I need to at least make an estimate.
We're probably talking like 3-8 or 4-9 lb/min. In that area.
one question...after I set the wot fine tuning mode and I want to go back to the base,middle and wot tuning...I switch the 4 mode switch to the off position???and what about the knobs...do I have to put them back where they were??? I know this things saves your settings afer you move the knobs...but since they'll be all in zero..I have doubt with that thanks...
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