Has anyone tried running the later model 3 bar MAP from a ecoboost (cx2231) on our cars instead of the GM part/kit route? Looks to be plug and play other than adjustments in the tune for the new sensor. Any input on this is appreciated.
2 bar MAP to 3 bar MAP...
- Thread starter SVTF
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I would suspect it's because the factory one tops out at ~15 psi. It could allow more accurate tuning if any tables were based on boost?
I personally am interested in this because my aeroforce could tell me boost without taking up one of its two analog inputs with a second boost sensor.
That's not applicable to our cars. Everything in our ECUs pivots around the MAF sensor. Based on air volume and known air requirements of the engine load can be calculated. Load is then mapped against rpm, throttle position etc. to calculate timing and fueling.
No where is MAP sensor readings taken into account with the exception of barometric pressure for elevation changes. Honesty I don't know that the TMAP on our cars is even a real TMAP. If it is providing boost/vacuum no where in the tune is it referenced or used and I've never even seen a PID to data log or view it.
Rog. I'm not well versed in tuning, so I was just spitballing.
Then, I would assume, the only reason people would convert would be for indication.
Again there's no indication or reading of the factory TMAP that I know of. There are no PIDS to data log and get anything from it.
What I did was grab a GM 3 bar sensor and did some testing to get some readings from it and observe its properties. Here I was using a hand operated vacuum gauge to simulate vacuum and make sure I was getting the readings expected as spec'd on the data sheet.
I then hooked it up to compressed air for boost readings and using a dataq box capture the readings as part of my data logs.
The result is data logging boost which is very handy for observing characteristics of the blower in the various gears and temps etc.
This supplements the factory TMAP sensor and does not replace it.
The indication I'm referring to would be on my aeroforce. It's hooked up to OBD-II, which means it's getting it's boost reading from the ECU.
That's interesting. I wonder if it's inferred boost? Meaning you calculate it. That's how the factory boost gauges work on the GT500s. Based on the load of the engine you can easily calculate air volume and equate that to a boost value.
Unfortunately custom tunes alter load readings and such and the boost gauge is then inaccurate as the calculations are messed up.
I can re-check my various tuning / data logging solutions I have to see if someone has discovered a boost/vacuum PID but its definitely not been there over the years on these cars.
The aeroforce will read a boost reading from the factory ecm and its clipped at 15psi but im not sure where that comes from maybe the map sensor.
For tuning I believe Malcolm is right that the maf is used for map calculations. Theres a pid called "inferred map" that the ecu uses for calculations, I assume since its inferred its not coming from a map sensor. I was told by a tuner I respect that thats the pid the ecm uses for calculations like transient fuel, etc..
For tuning I believe Malcolm is right that the maf is used for map calculations. Theres a pid called "inferred map" that the ecu uses for calculations, I assume since its inferred its not coming from a map sensor. I was told by a tuner I respect that thats the pid the ecm uses for calculations like transient fuel, etc..
Great data in here! Why oh why didnt Ford put knock sensors on our cars! Thats my biggest beef.
Too much blower noise it would have messed with the knock sensors.
For those of you who want to datalog boost, look into the aem failsafe. I have it and it allows me to datalog afr and boost. plus it's both gauges in one so takes up less room.
It would be more that their current technology or ECU limitations they were working with just couldn't work correctly.
The J&S Vampire works perfectly so blower noise doesn't make knock sensors not work.
This is why I originally asked. I am not well versed in tuning and was having issues with providing the right info for boost readings. I have since talked to my tuner and gotten the correct info and I am just waiting for the weather to cooperate so I may get another datalog.
On a side note...I'm glad I could spark up some good conversation on the subject and that others could bring some good info to the table on the subject. I want to thank everyone for the input.
Did anyone ever verify if the T-MAP sensor is the one providing the boost readings that ODB reports?
Sure, you can do it. It is a linear device on the MAP side. The 2-bar values are defined with a couple of scalars in the PCM. Those will need to be changed.
Will the PCM express beyond 15.99? I'm not sure. 16 requires an additional place value in the binary world. Just like 63.99 vs 64 on the MAF.
Good luck...
Will the PCM express beyond 15.99? I'm not sure. 16 requires an additional place value in the binary world. Just like 63.99 vs 64 on the MAF.
Good luck...
Would you happen to know what the MAP reading is actually used for?
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