The MegaSquirt Project has experienced explosive growth other the years, with hundreds of new MS installations occurring every week - a phenomenal success! MegaSquirt has been successfully used in all aspects of Internal Combustion engine applications including R&D, Industry, Race, and Research. The MS project has transformed itself from a simple R&D project into a full-featured mature engine control system. To reflect this the support structure has also changed to meet the needs of MegaSquirt Users.
Moving forward, the R&D forums for MegaSquirt project are in a read-only mode - no new forum posts are accepted.
However the forums will remain available for view, they still contain a wealth of information on how MegaSquirt works, how it is installed and used. Feel free to search the forums for information, facts, and overview.While the R&D forum traffic has slowed in recent years, this is not at all a reflection of Megasquirt users, which continue to grow year after year. What has changed is that the method of MegaSquirt support today has rapidly moved to Facebook, this is where the vast majority of interaction is happening now. For those not on Facebook the msextra forums is another place for product support. Finally, for product selection assistance, all of the MegaSquirt vendors are there to help you select a system, along with all of the required pieces to make it complete.
Forum rules
Forum rules
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
When the documentation was written it was planned to provide a calibration curve for MAF the same as for coolant. This has not yet happened, but we know that the capability to do this is going to come out shortly in Tuner Studio.
I have been busy working away on a flow bench for testing MAF sensors. Bench is complete but I now need the time to actually flow the sensors....
I also developed a program that takes the measurement and "fits" the response curve to King's equation, which is a model that represents hot-wire anemometers. The form is Volts = A + B * flow ^ C where A, B, and C are coefficients. Its kinda ugly with the exponent being a variable but this determines the bow in the curve.
The goal is to determine the A,B,C for a lot of the MAF sensors out there and have a mechanism to generate the curve. In fact, Tuner Studio will take A,B, and C and generate the curve and upload into MSII.
Now in reality the curve may still have to be "tweaked". Any air cleaners, ductwork, etc will change the response. Also, any air sources that do not go thru the MAF, like PCV valve, idle air, etc, will change the curve indirectly. So you may still need to tweak up the curve with the tuning software. But it is extremely easy to do and takes 5 minutes in the driveway, it is much, much, much easier to do than to determine a VE table for sure, but the tweak step is important.
Finally, MAF sensors are going to become required equipment, as will the MAP sensor, when we release the experimental model-based code version - it uses both sensors to compensate for manifold filling/emptying effects which generates errors during transients. At some point we may be able to replace the MAF with an isentropic throttle airflow model but first stab will need a MAF.
BTW - I am running a vehicle on MAF mode and its real easy to tune and keep at stoich - once the sensor curve is tweaked...
I just built and now have a V3, MSII, code 2.886 running. I was thinking of adding a MAF sensor to it. On the vehicle you are ruining MAF on are you using blend option with MAP? Can you give a quick blurb on how got it setup and running using MAF?
Great news, I was beginning to think MAF sensors were out of ‘fashion’.
I’ve been running MAF for a while now and as you say they are so easy to tune via the correction table even though I’m stuck with the default curve (for now).
I’d be up for some testing if you need volunteers. Keep up the excellent work guys
Bruce used just pure MAF. When he gets a chance we will be testing many different algorithms. Before installing it on the car he measured the flow on the MAF sensor with very accurate equipment. He flowed the entire setup, including the intake tract and air filter. He installed this curve, but still needed to make corrections on the car using the maf correction table that is in MT. As best I remember what he told me, he put in corrections to force the measured AFR to = target AFR. Bruce can expand further if he gets a chance - he is on travel this week.
The blend mode is used to expand dynamic range - if for example your MAF won't measure enough flow because you installed a turbo, and your MAP bounces all over at low rpm, then you can use the MAF there and bring in the map at high rpm.
