Hi!
As I´m new here I´m wondering if Megajolt can be configured to interrupt ignition while shifting. The Process could be triggered by an external switch.
Does anybody know if this is possible?
Kind regards
retman
Ignition-interruptor while shifting
Moderators: JeffC, rdoherty, stieg, brentp
Interesting idea.... You
Interesting idea....
You can't interrupt the ignition solely by doing something/anything to the MJLJ due to the way it works in conjunction with the EDIS module:
- if the MJLJ commands a certain advance to the EDIS, EDIS will give that advance
- if the MJLJ stops sending advance commands (which is the only thing you could realistically get it to do), the EDIS will continue to supply sparks but at a fixed 10BTDC
One way to interrupt the ignition on gear change would be to "T-into"/invoke an external hard rev limit circuit with your switch - unfortunately, MJLJ doesn't have an onboard hard limiter. If you do a search on this forum you will find plenty of views about potential hard rev limiting solutions.
I have built a very simple hard rev limiter that works well on the bench and is about to be tested on a rally car. I will be reporting back in a couple of weeks...
You can't interrupt the ignition solely by doing something/anything to the MJLJ due to the way it works in conjunction with the EDIS module:
- if the MJLJ commands a certain advance to the EDIS, EDIS will give that advance
- if the MJLJ stops sending advance commands (which is the only thing you could realistically get it to do), the EDIS will continue to supply sparks but at a fixed 10BTDC
One way to interrupt the ignition on gear change would be to "T-into"/invoke an external hard rev limit circuit with your switch - unfortunately, MJLJ doesn't have an onboard hard limiter. If you do a search on this forum you will find plenty of views about potential hard rev limiting solutions.
I have built a very simple hard rev limiter that works well on the bench and is about to be tested on a rally car. I will be reporting back in a couple of weeks...
Why do that? Is it a drag
Why do that? Is it a drag car?
No Drag car....
...it´s a boat and the stern drive is hard to shift under minimum load!
interruptor
Hi Martin!
Sounds quite well. The actual setup (BTW: it´s a boat) has a so called "electronic shift assistance module" which decreases dwell substantially while shifting. This causes in quite lower torque an the dog-clutches of the gearbox can easily be shifted against the backlash of the dogs. But the system isn´t functioning very reliable....
Do you think this could be possible withe the megajolt?
Sounds quite well. The actual setup (BTW: it´s a boat) has a so called "electronic shift assistance module" which decreases dwell substantially while shifting. This causes in quite lower torque an the dog-clutches of the gearbox can easily be shifted against the backlash of the dogs. But the system isn´t functioning very reliable....
Do you think this could be possible withe the megajolt?
Very interesting - not heard
Very interesting - not heard of a MJLJ on a boat before. You may be the first!
If you had a MJLJ with a TPS but were willing to forgo the normal 3d mapping capability that the TPS gives, there might be a solution along the lines of...
...wire a shift detecting switch into the TPS input rather than a normal throttle pot (needs a small amount of design which we can do if you want to progress it)
..set up the row in the map that is active when the switch IS NOT activated to be the 2d advance (ie just advance vs rpm) you want for the engine
..set up the row in the map that is active when the switch IS activated to be the 2d advance in the other row plus or minus the change in advance you want when shifting.
It should work....although it doesn't cut the spark when you're shifting as you originally requested
If you had a MJLJ with a TPS but were willing to forgo the normal 3d mapping capability that the TPS gives, there might be a solution along the lines of...
...wire a shift detecting switch into the TPS input rather than a normal throttle pot (needs a small amount of design which we can do if you want to progress it)
..set up the row in the map that is active when the switch IS NOT activated to be the 2d advance (ie just advance vs rpm) you want for the engine
..set up the row in the map that is active when the switch IS activated to be the 2d advance in the other row plus or minus the change in advance you want when shifting.
It should work....although it doesn't cut the spark when you're shifting as you originally requested
So, Car, airplane, and now
So, Car, airplane, and now boat applications? 
On the V3 boards there's an AUX input available which could be made to trigger the rev limit when activated. Should be a pretty easy modification to the firmware.
On the V3 boards there's an AUX input available which could be made to trigger the rev limit when activated. Should be a pretty easy modification to the firmware.