De-meshing MAF

Welly said:
Ok peoples, the results are in....

It's given me some extra flow.

I saw 210 the other day when it was on the rollers, but I haven't seen more than 207 recently on the road.

With the MAF demeshed, I just got 214.86 G/S.

With which I am well chuffed actually. :) An extra 8.75 BHP for removing a bit of plastic? Shibby.
Click to expand...

Nice one:icon_thumright:
 
Yeah just to ad, if doing this you may aswell smooth the airbox out and fit a green cotton panel filter.
 
Wasn't at Bill's today as the missus is away and the kids are home so found myself with some time on my hands.... I de-meshed my MAF and got a gain in airflow...

I took a few pics and did some test runs using my Liquid Gauge... I should mention that I was also trying out an MBC too but I will write that up in my build thread a bit later.

Needless to say the gains were impressive considering my MAF is not at its best.... I essentially saw a 9g/s gain relative to the tests I was doing with the MBC and boost levels. I was testing g/s gains from increasing/decreasing boost, got to a boost level I felt comfortable with then de-meshed the MAF, fitted and went back out and saw a 9g/s increase....

<tuffty/>
 
So when welly does it everyone takes notice of him but when i did it last year everyone slated me, eh haha :shrug:
 
Dani_B19 said:
So when welly does it everyone takes notice of him but when i did it last year everyone slated me, eh haha :shrug:
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LOL... I was prob one of them... as far as I am concerned the mesh is there for a good reason and personally wouldn't recommend anyone do this mod but happy to provide enough info for you to make your own mind up about doing it.

Obviously when anyone does this they do so at their own risk/pocket... I am still not saying do it or not but I have now done this and seen gains, long term benefits I don't know about as yet, people say that they haven't noticed any issues but then there are people driving around with boost leaks, vacuum leaks and MAF's that are not at thier best without noticing so I won't be taking that as a recommendation... :)

I will update my build thread with the pics and findings of today and you can all decide if you want to do it or not then :icon_thumright:

<tuffty/>
 
done it years ago on my gti turbo, noted nothing special,

The mesh on the maf is used to smooth out airflow to ensure the sensor has the best chance of a steady reading.....Fact

So your readings may not be what it seems if it is getting a slightly inacurate reading......so sorry guys get the glue out :)
 
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The mesh in the MAF housing has the function for getting a lateral airflow. Without it the airflow is whirling.
I personally think it's there for a reason.
 
s3dave said:
done it years ago on my gti turbo, noted nothing special,

The mesh on the maf is used to smooth out airflow to ensure the sensor has the best chance of a steady reading.....Fact

So your readings may not be what it seems if it is getting a slightly inacurate reading......so sorry guys get the glue out :)
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This can be checked by keeping an eye on long term fuel trims... if the value starts going negative over a period of time then this would indicate that the ECU is taking fuel out to correct what it thinks is more airflow from the MAF... if this value stays steady then its a true gain in airflow...

<tuffty/>
 
tufftybloke said:
This can be checked by keeping an eye on long term fuel trims... if the value starts going negative over a period of time then this would indicate that the ECU is taking fuel out to correct what it thinks is more airflow from the MAF... if this value stays steady then its a true gain in airflow...

<tuffty/>
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yes that is about the only solid evedince long term fuel trims, i sincerley hope you do get gains, it will be interesting....:icon_thumright:

just sceptical why a manufacturer would put it in, if it was infact a bit of a hinderance, after all they wont want to spend one penny more on a part than absolutely nesasarey (sorry for spelling ,)
 
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s3dave said:
yes that is about the only solid evedince long term fuel trims, i sincerley hope you do get gains, it will be interesting....:icon_thumright:
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Indeedy, I will be monitoring mine. Well happy with that logging session, didn't see more than 3s from the knock sensors, despite running ridiculous timing advance!!
 
s3dave said:
yes that is about the only solid evedince long term fuel trims, i sincerley hope you do get gains, it will be interesting....:icon_thumright:

just sceptical why a manufacturer would put it in, if it was infact a bit of a hinderance, after all they wont want to spend one penny more on a part than absolutely nesasarey (sorry for spelling ,)
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I too am a skeptic in such matters... I totally agree that the mesh is there for a reason but then modding isn't designed to really care about what the manufacturer thinks :racer:

In terms of air flow and accuracy in measurement on a de-meshed MAF, the airflow is measured by measuring the current draw (converted into a voltage for the ECU) it takes to to maintain heat in the MAF element. Airflow is directly proportional to the current draw... while the mesh does stabilise the airflow across the sensor it will still be measuring the amount of airflow it takes to maintain the heat in the element...

If anything I would imagine it would under read the airflow but I guess time will tell as will logging to see whats going on... I may well start logging block 001as this shows the level of adjustment the ECU is making in real time to keep AFR right. If this value is swinging wildly or is of too large a value at any one time, that would suggest the ECU is fighting its other sensors trying to keep fuelling right (I think thats right anyhoo) :)

<tuffty/>
 
will be good to see long term logs. ive descreened just about every MAFd car ive had
 
So the general result from this was their wasn't any noticeable diffence if you de-meshed it anyway?? Mine has 2 meshes on it pre and after the sensor. Not sure I want to risk this but this thread did get me thinking....
 
quite the opposite in tufftys and wellys experience

maf screens are there to guide turbulent flow into a more laminar flow across the sensor element (which is being heated to a constant temp, and the current draw it requires to maintain this temp with respect to a reference is what is proportional to the Mass Airflow thru that diameter tube.. and outputed into a 0-5v which the ecu can read in its A-D)

worst case I can imagine is on part throttle, light throttle, on an open short induction kit, *may* possibly give a more unstable reading. I had similar phenomena years ago on my ibiza on cruise control, on an airbox feed which caused a buffeting of the airflow, and in turn made cruise control make me feel sick as it constantly accelerated and decellerated. Re-routed the airbox feed pipe to a more static air location and it magically went back to nice again.

Mass airflow across the sensor should still be mass airflow with or without the screen in place, and so long as it has 5 to 8 or more diameters worth of straight up stream of it, the airflow should be pretty consisten across the sensor elements heater element film
 
tempted to take the one after the sensor off... is it clipped in? Does it just wedge out with a flat head screwdriver?
 
Sadly, I have a different MAF to this, and I had to simply brute mine out. Mine doesn't clip out, it required being snapped to hell....

RIP Mesh!
 
Matt82 said:
whats the score with the long term logs then?
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Did a check on block 032 earlier and nowt out of the ordinary to report tbh... I have changed the MAF and airflow is more or less the same at the moment but I haven't had a chance to log properly just been using the functions on my Liquid gauge. Block 032 stands at -1.5% idle and -1.6% long term which is perfectly normal... will do another check at the weekend before I sort my EGT probe and lambda out.... might have a word with Jim at Race Diagnostics to get block 032 added to the Liquid as its a useful option to check...

<tuffty/>
 
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