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.
A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
I was wondering if code could be implemented in the GPIO&MSII to provide for a drop in engine torque (spark retard/cut and or fuel cut) while the GPIO board is commanding a shift. Many OEM's are doing this already to "improve"shift feel and prolong clutch-pack life. While i prefer a firm shift, the reduced stress on the clutch pack is apealing to me as it could dramatically increase the life span of a trans in a high HP aplication. while i realise that something like this could problably be done now utalizing the flat shift feature of the MSIIextra code, a CAN implemented dedicaded function would be a nice (even if seldom used) feature.
Yes, Al has the infrastructure in place in the B&G code for this, and the MShift code will use it to reduce advance/cut fuel during a shift (the code doesn't do this at the moment, but it will soon).
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Retarding the timing works fine in a NA application, but may be counter-productive in a turbo app. Typically when the timing is retarded the boost increases.
I think he's trying to avoid shifts at full engine power, something i've wondered about as well. Could it be as simple as a 1 second window during up/down shift where the MS2 pulls say ... 4* timing? (or some user configurable value)
You wouldn't want it to be for a full second I don't think! That is a long time compared to a nice, quick shift. RacerStev on here was datalogging shift times using some different controller hardware, and I don't remember what he got the shift time down to, but it was much less than a second (using valve body mods and software adjustments).
I've been wondering what you do with a turbocharged application to get this effect though (consistent with the comments above about retarding timing). Could probably do fuel CUT for an instant. It might make a cool boom sound like it does when overboost protection kicks in, and probably not damage the engine as long as it is a complete cut.
My thinking was to use the built in shift timers (which are a constant plus a factor based on line pressure - which in turn is based on load in the 12x12 table) to set the duration of the 'de-rating'. Typically the total duration varies from a few tenths of a second at high loads to almost a second (or more in some cases) at low loads.
There is some work on a sophisticated turbo control application for the GPIO going on in the background, and one of the possibilities is to open an electronically controlled BOV while shifting (as well as spark retard/fuel cut) - this maintains the compressor speed so boost is immediate after the shift. The person working on this wishes to develop it further before disclosing details however, so I won't say any more.
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Just a thought about triggering the knock sensor retard during a shift. It might be useful if any standalone controller pulls pin xxx high during shift.