NefMoto

So I've been doing a TON of reading and I'm trying to figure something out. I do not own Meastro tuning from Eurodyne, but I have screen shots of where they just pick which MAF sensor is that they use instead of tuning MLHFM. Would it be possible to get a MAF sensor and copy MLHFM from that said car? Say I wanted to install a Hitachi S4 MAF sensor on my car, could I copy MLHFM from that particular S4 and think it would get me in the ballpark? There are 3 hurdles that I see with this idea:

1- As stated in the S4 wiki there are quite a few different MAF part # for even the same year car, so the copied MLHFM would have to be taken from said bin.file that has been calibrated for said MAF sensor. (not really a hurdle, as I believe looking for said bin with said MAF part # would be much easier than starting from scratch)

2- I understand that the intake track, velocity, etc could, and most likely would be different from car to car. At this, we would have to fine tune KFKHFM for any differences.(This would have to be done anyway as stated in the wiki)

3- This would require MAF sensor and housing both from different car, so splicing wires comes into play. My only experience is changing MAF sensors, not swapping them. With that being said, I"ve never looked at the wiring in detail. Im unsure that all MAF sensors use the same amount of wires. If they have more or less, then it would kind of defeat the purpose.

I'm open to ideas, maybe I'm overlooking something?

If this all holds true, then we could set up something where you can go and choose your part # MAF, and with it you will find it's particular MLHFM map to copy into your file. The hardest part of swapping MAF sensors would be building the intake track to compensate, splicing in MAF. Almost plug and play, again, we would have to fine tune with KFKHFM for differences. I'd be totally willing to try this out on my car if someone has a used MAF sensor, preferably from an S4/TT 225 variant they want to sell (that's in good working order!).

Yes, you can do as you say.  I have changed from a Hitachi to Bosch MAF on my  own car for example.

Rick

There are only two MAFs used in the S4, one hitachi and one bosch. By and large, if you aren't going to use a stock sensor, you had better damn well have the datasheet for whatever MAF you intend to use....

Rick, did you by chance copy the MLHFM map over as I say, or did you just tune it until it was right? If you just tuned, did you compare your MLHFM map to that of a car using the Bosch sensor? Thanks.

Well that's good advice, I'm trying to stick with S4 sensor because you all have more info/experience with those. Do you think it would be easier to just scale the stock sensor inside different housing nyet? The way I understood meastro was they swap out the whole sensor. I could very we'll be wrong about that. Thanks nyet for your reply. I'm really interested in figuring out MAF as it seems from everything I've read, if you can get that part right, tuning is much easier than if its wrong. If I did swap out MLHFM from an S4 into an A4, would I also have to change the minimum/maximum values?

Just scaled the whole thing by a constant %

http://nefariousmotorsports.com/forum/index.php/topic,617.msg8097.html#msg8097

back and forth between KRKTE/MLHFM until trims and max load are where I want it.

MLHFM is for a particular sensor, and KFKHFM is to correct the MAF reading for the intake tract.

I believe that MLHFM should be portable between tunes as long as the MAF is scaled correctly and not underscaled.

KFKHFM would be much less portable because it is directly tuned for a particular intake tract.

Right, that's what I thought. I know you big boys play with the S4's and have the Bosch/Hitachi sensors. It seems with 1.8t we have the same mlhfm for same size maf housing, regardless of car. It doesn't seem to matter which way the engine is mounted either. Kfkhfm, as you said, since it's tuned for the intake tract, are ALL different. I assume that the same mlhfm map will go with Bosch, as will one go with Hitachi sensors. I need some more time to look at a couple more bin.files to compare. I didn't have a whole lot of time tonight.

It seems from what I'm reading Audi uses the same maf sensor for the a4, tt, vr6. The housings are different, hence the ecu's different transfer function (mlhfm). This information was gathered from reading various forums, however NONE of that is close to being fact. Can anyone confirm or deny this? Its hard to clarify because part numbers refer to the housing, not the actual sensor. Can anyone post part # on their actual sensor w/yr, make, model. I will try to dig mine out later today. I believe Bosch is the manufacturer of all 1.8, so it would be good to get the Bosch s4 maf senso part number as well. Thanks to all responses.

Here's a GREAT picture a member of audizine just sent to me for comparison, notice the difference from appearence on the 225 MAF end? Other than that, the last letter letter of the part number is different.....which could mean a world of difference, lol

I'm  trying to figure out what you want to do, then I can advise better.

MLHFM is completely portable, and as Nyet says, you should match this to the sensor you have.  I am against scaling anything.  We have a good choice of sensors available with well defined transfer functions and the RS4 supports over 600hp so you shouldn't have a problem.

Once you have transferred the correct MLHFM, tune KFKHFM until your trims are correct.

Rick

I am still a bit confused on how ME7 handles load >191... got any advice/insight?

There are also a few MAF maximums in ME7 that I am concerned about.

I guess what I'm trying to do is find out how many different sensors there actually are. I just can't imagine that Bosch made 50 different sensors for 50 different cars. I have read of many people just using sensor "x" from a different car, putting it in their housing in their car, and everything is good. No bad logs of stft. I agree that scaling is not the first choice, however I have read that there is a mathematical formula to scale. I definitely don't have it. Is it plausible to use my sensor inside of housing "x" and mlhfm from car "x" bin? Hey, I'm just learning, so I hope this doesn't come off as a stupid train of thought. Thanks for the insight, and fwiw, I have learned a great deal from you folks.

If you are putting a sensor in a different size housing, you have no choice. You must scale


Typically, it is a constant % increase across the range of the stock transfer function. Math would indicate it should be proportional to change in cross-sectional area, but I have had varying results with that.


That is how almost all B5 S4 2.7t MAF modifications are done. I assume you have already read the MAF entry in the s4wiki?

The photo was mine.

I'm on here as well...  I still don't understand why you want to simply use the sensor you have in a different MAF housing.  Rather than simply using a different MAF sensor/housing and using it's respective MLHFM.

MLHFM is tied to the sensor/housing pair.......not just the sensor.


What MAF are you trying to use and what car is it going into?

Nyet- I have read the S4 wiki many times, thank you for your hard work, great job.

Mmmboost- I was really just curious. I appreciate your awesome pictures. Listen, 6 months ago I had no idea about eeproms, ecu, hexadecimal, etc. I'm just trying to learn all I can. This stuff is just starting to make sense to me....sometimes. The fact that I can respond to you all and follow what your saying is a friggen miracle in and of itself. And honestly, housings are a dime a dozen, and sensors get expensive. If I can find less expensive ways to do things, I will....no, I rarely ever shop on eBay for car stuff. I'm just trying to learn.

I forgot that you had asked me for some more MAF photos.

Here are some of the shots from my build thread of previous MAFs I have run.  I am now running a B6 S4 4.2L MAF.

http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6260959&viewfull=1#post6260959 (http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6260959&viewfull=1#post6260959)

http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6349884&viewfull=1#post6349884 (http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6349884&viewfull=1#post6349884)

http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6371157&viewfull=1#post6371157 (http://www.audizine.com/forum/showthread.php/366320-The-Build-A-GT2871R-build-documentary?p=6371157&viewfull=1#post6371157)

The ECU internally has an 8 bit and 16 bit representation of load. The 8 bit value is limited to 191%, the 16 bit value is not. The limit of 191% load is only for the systems and maps using the 8 bit value. I believe the 16 bit value is used almost everywhere, except when it needs to do a lookup on a map using an 8 bit axis value.

rl (0xff*.75=191) vs rl_w (0xffff * 0.0234375= something big) ?

i.e. 0x00F98B vs 0x00F990 in mbox?

Correct. VagCom measuring blocks only show you the 8 bit value. You have to use a RAM based data logger to see the 16 bit value.

I have question and think is good place ...
I want rebuild my TT for about 500HP and need to know which MAF is good and enough for that?
Can anyone help me?

RS4

Thank you :)

RS4 MAF is not available in our country so is here any other solution? With stock TT 225HP MAF i have 480HP but MAF gone yesterday :(

I want stay in about 480HP now because stock gearbox and haldex.

Audi s4 v8 maf should work for that setup. For the time being you could try dialing in KFMSNWDK/KFWDKMSN then moving to FVVKS (within map limits). Then beyond map resolution go KFLF first or KLAF. Rescale torque model maps and you should be setup to dial in the new maf.

When you are changing from tt 225 maf to rs4 bosch maf which maps should be copied?

MLHFM
MLOFS (keep it 200?)
MLFHFM?
KFMLDMX?
MLMAX?
KFKHFM?
FKKVS?

You just need to change the scaling the of the MAF initially, MLMAX may need to be increased, KFMLDMX if you get the engine check light , but if you're going with an RS4 maf you must be running a bigger turbo and a lot more maps generally need to be changed.

Thank you
I am upgrading from gt2860rs to gtx 2867r so the maf will hit its limits.
If I am not wrong the tt 225hp maf's limits is about 290 g/sec