This may be completely wrong but in my thoughts last night about single and dual vr circuits and the noise experienced with them. I was curious as to what adding something like an edis module to send the square wave to the ms that is in essence a modified square wave instead of the sine wave it would get directly from the sensor. That could work to straighten out the input and clean up any possible noise. Although this is completely out of the blue while I was looking at the edis4 setup. I don't know if just grounding the ground side and having the PIP from the module as the positive input or even if that would be too much voltage. If this has been done and failed, please let me know. I don't know if anyone has done this before, but in theory it sounds like a good idea to lessen the noise that occurs with the single input and to make it work to a great deal of rpm without fail. Think of it as a square wave conditioner I guess.

Discussion?

 

RE: EDIS; The problem is that PIP is generated once per rev IF it's given a 36-1 VR signal. I do know of a gentleman who was able to create a 72-2 wheel that fit into the CAS housing. EDIS does do a wonderful job of decoding the 36-1 wheel, no doubt about it.

-Mike

 

ah, thanks for that. I kinda came up with this in my mid morning stupor. Also I didn't know how the module worked completely. Good idea in theory I guess, but not quite right.

 

In my experience just grounding the engine properly and grounding the ms properly, using the correct lm1815 setup for the 2nd trig, and if needed running the new noise filters in ms2/extra 2.1.0 are enough to get a clean running engine.

I personally do not even need the noise filters.

Ken

 

I'm talking about a single vr circut, not a dual

 

I'm sure I'm missing something simple but why can't you use a 36-1 trigger wheel on the crank pulley and the ford EDIS module? I've never tried this on a rotary but it works like a charm on all the boingers.

 

It's been done and works nicely for firing leading and trailing at the same time with no split. The EDIS-4 decodes the 36-1 signal and emits a PIP signal each 180 degrees and uses the SAW signal to fire the Ford EDIS-4 related coilpack at the desired advance angle. It does NOT emit a raw square wave corresponding to the wheel teeth; therefore the MS-Extra code is not getting the input necessary to calculate leading/trailing timing. It would be wonderful to be able to obtain the EDIS' internal VR zero-crossing detector output but it's not externally available. As Ken has stated, a properly assembled 1815 circuit works very well. i personally use jbperf.com's dual 1815 board to obtain very clean, trouble free waveforms from the stock Mazda CAS. It cannot be overstated that meticulous attention to the wiring is the key to attaining a problem free install.

-Mike

 

Also, many people don't want to put a crank wheel on when they have a perfectly usable ignition setup stock. (I sure didn't want to).

On any of the engines I've worked on, if there is a usable ignition system already on there, I don't want to go welding the 36-1 to it and removing the existing system.

I also don't recommend modding the CAS. IMO it's much easier to build a 2nd trigger circuit and get the engine working correctly than it is to cut 2 teeth out. The missing tooth config is more prone to noise, and in my experience just doesn't work as well.

Ken

 

I'm not going to modify the stock CAS for a few reasons. One being reliability and the other is I don't want to have my cars set up dependent on parts that are hard for me to replace.

I'm own a small cnc shop so machine a trigger wheel is easy enough for me to make. I also don't weld mine on unless I absolutely have to. Typically I make them for the specific application and find a way to bolt them on. This also allows me to set the exact position of the wheel to where I want it.

I'll have to look into the dual 1815 board. It sounds like a much more graceful solution.

 

There you go. That sounds like an excellent plan!