MAF usage

[techsalvager]

Has and can anyone show a working example of a setup with maf being used?

The custom cal tables for maf don't seem to setup well and I would like to see what people have done. I'm failry interested in buying the g4+ extreme but this is something I would like to find out what the support level is at for in it software\hardware.

 

Thanks

Justin

[Simon]

Hi Justin

Although there is the ability to bring MAF into the ECU it is really designed to operate off MAP.

Hence there is minimal MAF support.

[techsalvager]

Simon I went though the forums and saw some people had it working but noted how they had to do it.  I was looking at the way the table is setup for the maf transfer function under custom cal tables.  Could the grams\second area become user editable for each cell instead of having to set a start point and width of each cell.  Seems like a lot of the back in for proper maf support is there with the fuel modeling. 

I was\am also interested in the haltech elite 1500 unit but certain features in it seem like featureless features compared to the link g4+ extreme and while they do have the maf support they don't have much defining the injector model.

My big question is there anything really stopping even having a usable table of 16 ( if not 32 points or more ) points that can be adjusted better than currently implemented?  

[ashesman]

As previously mentioned, MAF support is limited.  The reason for this is that while MAF is a very good indication of engine air flow and hence fuel required, it requires its own complex modelling, often engine and intake system specific.  The MAF reading is accurate at steady state but less accurate under transient due to manifold and intake track volumes.  It is possible to get a very accurate and repeatable tune without using a MAF sensor.  Many modern vehicles do not use MAF sensors any more and almost no aftermarket installations do.

My opinion is that you will get a better tune from a MAP based install than a MAF install on our ECUs and most other aftermarket brands.  While they may support MAF sensor just as we do, check they offer all the correct modelling and compensations to get a reasonable tune first before buying other wise you may end up switching to MAP in the long run.

The use of a permanently fitted oxygen sensor will be required to get a good tune for minor variations whether using MAF or MAP so ultimately the engine will probably end up running the same AFR but at least with MAP there is good transient performance.

Good injector characterisation is essential especially if you plan to use large aftermarket injectors, this can make or break having a big injector engine that can also idle and cruise nicely.

[techsalvager]

My next question would be, whats the point of having the ability to input a maf into link\vipec ecu's as of now?  

[Simon]

The reality is there isn't much point.

[Nate20det]

Does anyone know if the standard link g4 can still do the mafless tune

[0x33]

23 minutes ago, Nate20det said:

Does anyone know if the standard link g4 can still do the mafless tune

Basically all Link ECU's will run speed density (MAP) rather than MAF, so yes. 

[Geggu]

Hello All,

I have a V3 JDM Impreza running a V3/4 LINK Plugin ECU... I'm having a problem getting my MAF Calibrated, its constantly reading high Charge Temperatures, and i know the temps are not that high.

I am still basically running the V3/4 Base Map that came with the ECU but i have installed AEM IAT in my Intake Manifold.... So my questions are, is the MAF being used on the Base Map provided or can it be deactivated?... Can you provide information on how to deactivate it?.... and if the MAF sensor is indeed being used, how can i get it properly calibrated?

 

 

[Adamw]

No the MAF is not being used at all in our base map.  Charge temp is a combination of air and water temp - do you have the charge temp approximation turned on and set up?  What temperatures are you seeing and why do you believe they are wrong?

[Geggu]

29 minutes ago, Adamw said:

No the MAF is not being used at all in our base map.  Charge temp is a combination of air and water temp - do you have the charge temp approximation turned on and set up?  What temperatures are you seeing and why do you believe they are wrong?

I'm seeing Charge Temps of 70⁰ Celsius and up.. and I even relocated my intake to my fender for cooler air intake.... i am still basically on the Base Map so not sure if Charge Temp Approximation is on and setup...

[Adamw]

Charge temp is not intake air temp - it is the approximated temperature of the air that is entering the combustion chamber after it is heated by the hot port walls, intake valves etc.  At low speeds charge temp will be close to water temp, at higher speeds/loads charge temp will be closer to air temp.  

If you are using traditional fuel equation (as per the base map) and you dont have charge temp correction enabled (the base map doesnt) then the charge temp means nothing, it will not influence fueling at all.  In this case you should be looking at IAT (Intake air temperature). 

[Geggu]

2 hours ago, Adamw said:

Charge temp is not intake air temp - it is the approximated temperature of the air that is entering the combustion chamber after it is heated by the hot port walls, intake valves etc.  At low speeds charge temp will be close to water temp, at higher speeds/loads charge temp will be closer to air temp.  

If you are using traditional fuel equation (as per the base map) and you dont have charge temp correction enabled (the base map doesnt) then the charge temp means nothing, it will not influence fueling at all.  In this case you should be looking at IAT (Intake air temperature). 

Noted... Thanks Adam!