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.
Hello, I am trying to get my trigger offset set but no matter what way I move from zero it doesn't change a thing. My mag pickup is set right at about 5 degrees BTDC. Sitting there running at idle its firing at 0 to 1 degrees BTDC, but I can not get the 8 to 10 that the computer is wanting no mater if I burn the trigger offset to 5 or -5 it doesn't change anything. The engine is a 2 cylinder motorcycle engine and idles roughly around 1300rpm. Is there another setting that I need to adjust for the MS to predict better. It will have to fire about 3 degrees before it gets its signal from the mag pickup. It is a MS-II V-3 board running code version 2.891
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When I assembled the board I used the setup to control two LS1 coils using wasted spark per cylinder. Both coils fire at the same time every rev.. If that is any useful info..
I dug around in the manuals some more and found a section on trigger offset with some more info and an example. It showed that to change the timing by 2 degrees it took 10 degrees of offset. So I tried using bigger numbers and found that timing is moving as I change the offset. I'm still having trouble getting it set to match MS ignition adv., the big number. It will not advance any degrees before the mag. pickup sends its signal. So the most adv. I can get is about 5 degrees BTDC. I can move it in the other direction ATDC till the engine dies, but going any further than 5 BTDC it just stops and hangs up around 5 degrees and will not advance any further.
Lesson learned. ALWAYS REREAD AND DO THE MATH. I dug deeper in the manuals and was wondering just what the burn time of the gasses in the cylinder were doing. Surprisingly, if 17 degrees ATDC is optimal peak pressure then for my engine at a bore size of 2.95in. with the plug located offset 2in. to one side, the burn time is 2.2 milliseconds at 1,300rpm. Which put in the formula equals 17.16 degrees traveled till burn is complete. When you minus the 17 degrees until peak pressure I get: .16 degrees BTDC advance timing. I'm so used to bigger V-8s that I tried to use the same logic, doesn't work. Once I started to use the bigger numbers for trigger offset I noticed that the reason I couldn't advance any more than 5 degrees BTDC was because it was running so rough that it would die, should have set a light bulb off in my head, but because I just knew that the advance should be higher, it never did. I did notice that the closer I got to 0 degree TDC the engine did run smoother and I though I had screwed up on marking the degrees on my crank hub, which I rechecked to make sure that was not the case. Once I went back and did some more reading it became apparent what was going on inside the engine. So with that in mind, I have an entire spark map to recalculate, USING THE FORMULAS. Thank you so much Bowling and Grippo and all independents for all the info and time that has been put into this.