MAF Support

This is a forum for discussing the development and testing of alpha MS2/Extra code. Documentation
(Runs on MS2 and Microsquirt)

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Maddog6961
Helpful MS/Extra'er
Posts: 134
Joined: Thu Sep 01, 2005 8:33 am

MAF Support

Post by Maddog6961 »

Is there plans for MAF support in MS2 Extra? I haven't been able to find any documentation or information about this feature. I'm sure someone has asked before but the search function kind of sucks and I am never able to find anything that I am looking for.
George Carstens
1984 BMW 533i turbo
MS II Extra Beta
http://www.wreckracing.com
muythaibxr
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Joined: Thu Oct 14, 2004 12:48 pm

Post by muythaibxr »

We eventually intend to support MAF, although probably not with the use of a transfer function. It'll most likely be added as another option for Load.

Ken
Maddog6961
Helpful MS/Extra'er
Posts: 134
Joined: Thu Sep 01, 2005 8:33 am

Post by Maddog6961 »

Sounds good in my mind. I'm gonna give it a shot when its out. Any ETA? I know you guys work hard enough as it is though, so I don't expect it anytime soon.
George Carstens
1984 BMW 533i turbo
MS II Extra Beta
http://www.wreckracing.com
muythaibxr
Site Admin
Posts: 8228
Joined: Thu Oct 14, 2004 12:48 pm

Post by muythaibxr »

I'm not really sure when we'll do it...

Do those who want it want to be able to use it in parallel with the MAP sensor or in place of?
Maddog6961
Helpful MS/Extra'er
Posts: 134
Joined: Thu Sep 01, 2005 8:33 am

Post by Maddog6961 »

I would like to be able to use it as a blend of the two like the standard code does. I would like megasquirt to rely on a MAF for steady state operation and have the MAP sensor for transient response.
George Carstens
1984 BMW 533i turbo
MS II Extra Beta
http://www.wreckracing.com
W113
Master MS/Extra'er
Posts: 472
Joined: Tue Dec 05, 2006 3:35 am
Location: Sweden

MAF on a "hobby" car

Post by W113 »

The one really good reason to use MAF is that it measures ACTUAL intake air mass, not a derived quantity thru MAP and known intake tract behavior.
This MAF predictability is great for volume cars that shall run and run for 10-20 years with no, or not much, tweaking. The MAF will always give a true air mass signal, no matter how much the intake tract flow changes. Worn camshaft, sooty valves, clogged air filter etc is no "problem". Base fuelling will be right.
One very unloved aspect of the "hot film" or "hot wire " MAF is that it is quite prone to measuring errors. After 50 km it is not at all unusual to have to replace the MAF sensor, which is quite expensive. There are quite a few reasons for this, but the most common seems to be silicone oil contamination. The silicone oil is not burned off by the standard cleaning cycle used.
So, for me a MAP sensor seems perfectly adequate in our type of installs, and it is also quite a bit less expensive and absolutely trouble free to install.

I have just helped friends with diagnosing erratic starts and running on a BMW 5 series and a MB 420. Both traced to MAF sensors. We tried to use a special silicon cleaner, but no real success. After just a couple of days performance was back to precleaning, measuring only about 1/3rd of the actual air mass.
The BMW , being a 02 M5 set us back with 2 MAFs, but what a car!!!

So, I recommend that MS sticks with MAP as base with MAF as a possible alternative.

W113
If not understood , it will not work
Maddog6961
Helpful MS/Extra'er
Posts: 134
Joined: Thu Sep 01, 2005 8:33 am

Post by Maddog6961 »

I don't think anyone is talking about replacing the map sensor with only MAF support. I know I would just like to have it as an option.
George Carstens
1984 BMW 533i turbo
MS II Extra Beta
http://www.wreckracing.com
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