NefMoto

Hi to all, I have read a lot of usefull stuff here and I wish soon I can learn more and more from you guys... So now I have a question... We made a K04 ibiza 1.8t with 440cc injectors and 3" maf... but Maf´s are failing to soon and Map seems to be very MAF sensitive... with Maf unplugged car runs perfect so I would like to dissable MAF trouble code, engine light, etc from the file. Just like a Cat delete. Can anyone help me figure this out?

Here is the Ori file.

Thanks!!

If you want to run MAFless go standalone. Pointless to use ME.

MAF is primary load input in ME7, but CLALM and CDTLM will help.

really?????

Mafless and nefmoto=rs6x/t/f/sedad turbos and audizine.

Hi ddillender!

Please explain, what you meant.

I meant it stirs up debate, and people argue. Much like the rs6x turbos on Audizone.

Mafless with motronic is a hot topic.

Thanks.

That's why I've asked you about this. I think to use MAFless as well but I don't know it's a good idea or not. I have tuning camshafts and GT28RS turbo.

^^ It is never a good idea to remove the primary load input to an ECU.

Mafless is not worth the effort because the car will never be able to run 100% correctly.  With that turbo, using a VR6 MAF will be easy for you to do.

I agreee with you, but many people disabled MAF. Also I can't undrestand how torque-model work without MAF...
Do you have the PN and spec for the VR6 MAF?

For what reason? Seems like all the people asking how to delete their MAF don't really know the answer other than "others are doing it", which isn't a good reason.


Exactly. It doesn't.

Many of the tuners that offered MAFless tunes are now no longer offering them because it crap and not worth the headaches.

That should tell you everything you need to know about wanting to go MAFless.

As for the MAF, google is your friend :)

But Mafless could have benefits.
Some motronics switch later to map running but when MAF don't detect correct mass flow it could make too much boost or/and run too lean. :(
Maybe not all motronics.
I'm there no expert - but that is the only reasons I know.
Maybe also a reason want to sell a aftermarket ECM.

The ME7's that have MAF don't have a MAP sensor, very simple.
Only a charge pressure sensor before the throttle plate, which is completely useless for air charge calculation except for WOT.

It's maybe call T Map sensor but about the complete functions I have no knowledge.
I only know engine break downs because of damaged MAF sensors. :(
Something with the generation of the mass flow.
But when everything is fine - it seems to be better.

Suddenly... I thought that ME7.5 has both MAF and MAP sensor.

Map would indicate it's measuring manifold pressure, as in vacuum as well. Not the case here.

It does not. I suggest looking at the hardware you are trying to tune and realizing that the sensor is before throttle plate, so completely useless for calculating air charge unless throttle is fully open. MAP means manifold absolute pressure. ME7.5 with MAF has no pressure sensor in the manifold.

But if we know intake pressure and intake temperature we can calculate mass air consumption with the formula something like below:
MAC = FE * Vcyl * P * 293 / (273 + TA) * K
FE – percent of effecient
Vcyl – volume of cyl
P – intake manifold pressure
ТA – intake air temperature
K – conversion factor of dencity

Do you mean ME7.5 hasn't MAP in stock at all? How people using MAFless connect MAP to ME7.5?

Just ask britishturbo what happens when you try to use the charge pressure sensor to read manifold pressure :)


That is correct. There is no sensor measuring MANIFOLD pressure. Charge pressure, yes. Manifold pressure, no. It'll never read lower than barometric given the sensor location.

MAFless on ME7.5 has nothing to do with the MAP. Its because the primary o2 is wideband. MAFless is still not ideal though.

Like others have said, it's a true MAP ie. not measuring manifold pressure.

Thanks guys! It's absolutely clear now.

Which is load factor with MAFless, throttle?

Yes, RPM x Throttle (Alpha N).
The charge sensor is also considered, but only at high throttle opening. So with all normal driving you are only driving from alpha-n which is not very good on a turbo engine.
Even if you have wideband to correct the mixture, your ignition timing is still all over the place...

I see. But I thought that throttle is load factor for ignition timing as well.

Yes, but it is impossible to accurately determine load using RPM and Throttle on a turbocharged application.
The only way it even runs somehow in vacuum area is because of wideband O2 correcting mixture.
But because it does not know load correctly, the ignition timing is impossible to calculate precisely.

I agree with you. Just to clarify, in order to use MAFless need to use some customs binary flash file or can change load factor in stock file?

Does the stock sensor read vacuum? If so move it to behind the throttle body so it sees both positive and negative pressure

Just disconnect MAF, and you are in limp mode. MAFless = limp mode.
If you want to do speed-density, then you need custom code.

And then what? ME7 does not know what to do with that.
This moving assumes making a hole in the manifold somewhere also...

And start disabling implausible pressure sensor codes :D

That's the least of the problems ...

Was just an out there idea, not something I'm looking into just threw it out.

And all this work (which I am absolutely positive that anybody looking to delete their MAF doesn't have the ability to do)... for what? I have yet to find a single good answer to the question.

This alone tells me the correlation between wanting to delete your MAF, and not knowing how to *basically rewrite the load path* in ME is 100%.

Anybody who has the ability to do that level of modifications to ME certainly would know better, and would certainly not be posting here about how to do it.

Well, I am doing it, because on high horsepower cars the maf just pegs.
I did it on the 2.2T 5 cylinder, and I am gonna do it on ME7. But properly, by using a proper speed density calculation and replacing the MAF with a MAP sensor.

As for posting on how to do it, not going to happen in the foreseeable future. 99% of people who think they need this actually don't and don't understand the downsides of running no MAF.
How about re-tuning your entire VE table every time you change something, as simple as a camshaft or a box in the exhaust?
How about needing a steady state dyno EVERY time to calibrate the VE table in the first place?
How about getting lean startup issues on a hot car because your IAT sensor gets heat soaked?
How about getting massive acceleration enrichment problems because the MAP signal is way slower than a MAF?

And so on.

I agree with your all items except the below:

MAP is faster and less inertial than MAF.

With this, if you were to tune the airflow over throttle plate map according to MAF readings and then disconnect the MAF, that might work better no?

I understand MAF is better, just curious.

You are wrong, I can say that for sure, because I have experience writing mass-flow and speed-density code.
speed-density needs much more acceleration enrichment than mass-flow. MAP signal is much slower. In fact I had to quadruple the transient enrichment maps.

I have no interest in limp mode hacks when I have the ability to write my own speed density code in the ECU and use a MAP sensor in the intake manifold.

So my suggestion was doable?

I don't move the existing sensor, I add a second one.
Everything is doable, the question is, can YOU do it or not.

I've got your solution for pegging the MAF on high power 2.7t cars. If you don't want to port your code to the 2.7 ecu's, I can get you the details via PM if you'd like.

Well beyond me being able to adapt it to happen. But fair play for making it doable. Bar ditching a load of inlet pipe work I can't see the benefit on the audi. In previous cars I've built on standalone I've gone alpha n on NA cars then speed density on NA and boosted applications. Would love to be able to do it, just so I can but that's about it. Maybe in a year or too of researching the me7, big props for pushing the me7 that far though

I respect people who can develope such code because I develope code in higher level program language. But physically MAF is more inertial sensor because it works based on heating effect of inside wires in sensor and as we know actually heating is very inertial process.

MAF reaction peak to peak is 15ms on HFM5.
In reality it is much faster as you do not have peak to peak spikes. The reaction is <3ms usually.

MAP reaction in the manifold is much slower. It is nothing to do with the sensor.

I have implemented speed density code and I have implemented different types of mass flow code. MAF is faster each and every time, MAP is slow to react to instantaneous changes, period. It's actually the biggest lie in the world of standalones, that speed-density is quicker to react - it's not. Even old hot wire MAF's react much quicker than a MAP signal change.
If you had ever written code for a air charge calculation, you would know that. Nothing more to say from me here - you can keep typing your yadda yadda, it won't make it true.