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 Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
I read in the manual that normal AE isnt disabled when x-tau is enabled. Is it necessary to have both on and tune both or should the normal AE be disabled by setting 0ms as enrichment or perhaps a high threshold and leave all the acceleration enrichment to X-Tau?
To me it sounds easier just having one type of AE active with less risk of messing everything up.
X-tau is a bit more difficult to understand intuitively what values to put in. We have a feel for what a 10% increase in pulsewidth will due, but no feel for what an increase in tau of 20 ms will do. So if your car needs a lot of accel enrichment, it might be easier to back off say 30 % on you existing AE and make it up with x-tau, then continue to phase out the existing AE and replace it with x-tau. But sometimes people find that a combo works best for them.
Another consideration fo rx-tau. On the beta list we have a greatly revamped x-tau code which people seem to like much better and find easier to tune. So you might want to consider going to that code before getting deep into x-tau.
Read a bit regarding the beta code. Does the 2.870 'released beta' contain the synced MAP sampling and changed x-tau or is it in later versions as 2.871t3?
Did some more and downloaded the ini file and answered the q myself. Im going to flash 2.871t3 and try to have a go w that.
Downloaded the 2.871t3 betacode in to the MS earlier today. After some adjustment of the x-tau parameters it runs very sweet. Accel enrichment was very easy to dial in to get a consistent AFR through the entire transient. Very good. I havent played that much w the deceleration parameters yet so there is some lean running after I release the throttle. Normal AE is zeroed out. One strange thing is that the x-tau seems to oscillate some times when im running on very light load an close to closed throttle. Might solve it by changing the treshold for MAPdot. Time will tell.
The synced sampling and possibility to offset the start of injection definitely increased the running quality at idle and low PW runnning. I set the offseted the injection start by 50% to ensure I didnt inject during overlap which helped.
Looking forward to the implementation of tempcompensation in x-tau.
These features should definitely make it to the next relase of the code.
I have noticed the oscillation in xtau correction between 99-100%, but I don't know how to get rid of it other that average it, which I hesistate to do because it might slow things down. As best I can tell from a simulation, this oscillation is a result of integer arithmetic. There is fluctuation in PW from many things like map fluctuation. If you put a lower lag factor on map (more smoothing on it) that might lessen x-tau. But I wouldn't want to do this unless it was possible to feel the oscillation and/or it was causing a similar high fluctuation in AFR. A 1 or 2% fluctuation in xtau correction shouldn't cause more than a 1-2 % change in AFR, which is hard to detect in a responsive afr.