Cam signal idea for full sequential
#1
Cam signal idea for full sequential
I asked this question a month or so back on miata.net forum and although I got some helpful answers I didn't get a direct answer to whether my suggestion would work so I am asking here. Here's the plan:
I'd like to loose my modified Mk1 cam sensor which is supplying the required cam signal for sequential injection, as it takes up room at the back of the engine and looks messy.
My plan is to remove 4 of the 5 stainless steel studs holding one of my Flyin` Miata adjustable cam gears and replace them with titanium or aluminium studs. Setting a mag sensor in front of the cam gear aligned with the studs should then provide me with one cam signal per engine rotation.
So what do you all think? What are others running full sequential doing?
I'd like to loose my modified Mk1 cam sensor which is supplying the required cam signal for sequential injection, as it takes up room at the back of the engine and looks messy.
My plan is to remove 4 of the 5 stainless steel studs holding one of my Flyin` Miata adjustable cam gears and replace them with titanium or aluminium studs. Setting a mag sensor in front of the cam gear aligned with the studs should then provide me with one cam signal per engine rotation.
So what do you all think? What are others running full sequential doing?
#4
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This is interesting...
Truthfully, I've never really thought about the behavior of a hall-effect sensor in the presence of non-ferrous trigger materials. But come to think of it, aren't the stock NB cam gears made of something other than steel? The NA gears certainly seem to be.
Actually, I think that the same principle as an eddy-current brake would apply here, since the hall effect sensors we typically use have an integral permanent magnet. Eddy brakes use non-ferromagnetic rotors or rails, and they work just fine.
So I question whether replacing a steel stud with a titanium or aluminum one would have any effect upon the sensor's ability to detect it.
(Also, I don't see anything about the Boundary cam gear that shows a sensor tab.)
Truthfully, I've never really thought about the behavior of a hall-effect sensor in the presence of non-ferrous trigger materials. But come to think of it, aren't the stock NB cam gears made of something other than steel? The NA gears certainly seem to be.
Actually, I think that the same principle as an eddy-current brake would apply here, since the hall effect sensors we typically use have an integral permanent magnet. Eddy brakes use non-ferromagnetic rotors or rails, and they work just fine.
So I question whether replacing a steel stud with a titanium or aluminum one would have any effect upon the sensor's ability to detect it.
(Also, I don't see anything about the Boundary cam gear that shows a sensor tab.)
#6
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steve, check the boundary engineering section or search for posts by TravisR about the cam gear. it's too new for the site I guess.
https://www.miataturbo.net/forum/t33797-4/#post416806
https://www.miataturbo.net/forum/t33797-4/#post416806
#13
The original CAS uses a hall effect switch and it is going to give a digital square wave pattern with a 0-5 volt range.
A magnetic sensor similar to ABS and 36-1 tooth crank wheels output an analog ac signal.
So long as the new sensor outputs a pattern that is recognized by the PCM it should be ok.
BTW, I just took my Tekscope out of moth *****, let me know if you need any waveforms.
A magnetic sensor similar to ABS and 36-1 tooth crank wheels output an analog ac signal.
So long as the new sensor outputs a pattern that is recognized by the PCM it should be ok.
BTW, I just took my Tekscope out of moth *****, let me know if you need any waveforms.
Last edited by mrtonyg; 06-23-2009 at 09:17 PM.
#16
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A wacky idea that I came up with a while back while thinking of how to add CMP back to my car w/o a CAS:
What if you mounted a hall-effect sensor on the top of the VC such that it read one of the lobes of a cam?
What if you mounted a hall-effect sensor on the top of the VC such that it read one of the lobes of a cam?
#18
I guess what I need is confirmation that mounting a sensor in front of a cam gear with 4 titanium and 1 stainless steel stud will give me 1 signal per engine cycle. The TECgt only uses this signal to provide a rising voltage between 180 and 6 deg BTDC compression for No. 1 cylinder - it's just a sync pulse, so no real need for accuracy (60-2 tooth crank trigger provides this).
This method would be a little cleaner (no requirement for pull-up resistors, less to go wrong etc) than the OEM CAS mod on there currently and give more space at the rear of the engine.