Innovator discovered something interesting
We should try to keep this thread on track.
He discovered that gutting the MAS let it see less air, so he had to use less his SAFC for less correction and his timing did not advance as far.
The problem is: To get the correct amount of fuel at a particular amount of air flow and RPM, the karmon frequency the ECU sees MUST to be the same. If the Karmon frequency is different the ECU will tell the injectors to supply a different amount of fuel
This can be done several ways but we will only compare 2.
1. Leave MAS alone and use SAFC to add more correction to lower the karmnon frequency.
2. Gut the MAS sensor to lower the karmon frequency a little then use the SAFC to correct tit he rest of the way.
THEORECTICALLY THE TIMING SHOULD BE THE SAME BECAUSE THE ECU MUST SEE THE SAME FREQUENCY.
The bold statement above is what is being debated. Let’s look at this scientifically, examine the validity of the data and examine the assumptions used to make this statement.
1. A statistically significant sample is needed to eliminate random variables that could mess up a test. Maybe Innovators ECU has a Glitch. Maybe he had an intake leak that was fixed when he gutted his MAS. To eliminate these possibilities we need a few more people to do this mod and data log timing before and afterwards. A statistics student will tell you 8 samples are a minimum and 30 samples are best to have significant data.
WHO ELSE HAS GUTTED MAS AND DATLOGGED BEFORE AND AFTER? ON THE SAME DAY AT TEH SAME TEMPERATURE, ELEVATION, GAS and DRIVING STYLE?
2. The statement is based on the ASSUMPTION that only factor adjusting timing is the MAS signal. The MAS sensor measures 3 things, Airflow, Temperature & barmetric pressure.
- What does SAFC do to air temperature readings? The ARC2 replaces the readings with constant values. Does the SAFC modify it at all?
- Does gutting the MAS affect the temperature it sees? Maybe since the less air is flowing across the sensor less heat is loss by convection so the MAS thinks the air is Hotter?
- What effect does gutting the MAS have on the barometric pressure? If the barometric pressure is lower the cars thinks its at higher altitude and will deliver less fuel to compensate for lower denisity air.
- This also brings up the question what happens when the MAS is used as a blow through design (some translater guys are trying this) if these values are that sensistive?
3. Does the elimination of the restriction affect anything?
Turbos do a much better job of pushing air than they do of pulling it.
- If the turbos do not have to work as hard because of gutted MAS maybe the intake charge is cooler?
- I think the ECU advances timing when air is cooler so that is probably not true.
- If the intake charge is cooler, it is denser so less fuel is needed for same volume of air.
The Vendor technical meeting at the national gathering was very interesting. GT-PRO has done a lot or work at trying to modify out stock ECUS. Brian Fuentes commented several times the 3S ECU is very complicated and hard to modify. I am in over my head and guessing on the rest of this thread so feel free to correct my ignorance, the impression I got from this meeting suggested the following:
The Supra ECU is easier to modify because fuel and timing adjustment tables are in on location, fuel/timing can be adjusted in one location, it looks like Toyota planned to make their ECU easy to modify.
The 3S fuel tables are all over the place, you have to find every place the ECU tweaks the fuel/timing tables to keep from messing up. It was obviously not designed to be modified.
The Reason I talk about the ECU is because what innovator is doing with his mod is changing the system just enough that the ECU jumps to a completely different fuel/timing curve.
Again just Guessing, but what I would really like to see is other daring people data log before and after gutting MAS to see if Innovators discovery is repeatable.