# SR20DET theory.



## zellx2004 (Sep 30, 2004)

I have a theory, but I'm not sure how it would work out. We all know that a tach from a SOHC KA engine will not work with a SR20DET swap, because of the 4 individual coils. Autometer makes a convertor, for installing an aftermarket tach with distributorless ignition systems. Here's the theory: Say a person bought the autometer convertor, could it be possible to Tap into the individual coil signals, and convert the separate signals into one signal?


say you have the 4 individual wires from the coils, connect that to the convertor, then connect the convertor to the tach wire near the ecu on the SR20det harness. Anyone know if this has been done? It just dawned on me today.


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## Harris (Nov 11, 2002)

It won't work. Do what everyone else does. Either get a KA24DE cluster, a Silvia/180SX cluster, or an Apex rev/speed meter.


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## bridrive55 (Aug 26, 2004)

Harris said:


> It won't work. Do what everyone else does. Either get a KA24DE cluster, a Silvia/180SX cluster, or an Apex rev/speed meter.


SAFC-II has a tachometer in it. I just posted my SAFC-II by the steering column and used it as a tach. Soon you get used to the revs, and you don't need the tach at all. 
There IS a way to make the KA24DE work on the KA24E tachometer. It's just rather complicated. I got mine to work until I wired in the SAFC-II, and now it doesn't work. I might remove my dash again next week, so I'll see if I can't get her to work again...


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## zellx2004 (Sep 30, 2004)

Just to get this right, I feel stupid for asking this but, I used to have a SOHC engine. I now have a n/a sr with the distributor rather than the individual coils. Think my tach will work with the engine? I have hud in my 240, and I can't find a DOHC hud unit anywhere.


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## kane2g (Jan 18, 2005)

zellx2004 said:


> say you have the 4 individual wires from the coils, connect that to the convertor.....


Think about that....
by connecting them all, you will probably make a short which is going to fire ALL sparkplugs.
CONGRATS. 4X the power :loser:


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## zellx2004 (Sep 30, 2004)

kane2g said:


> Think about that....
> by connecting them all, you will probably make a short which is going to fire ALL sparkplugs.
> CONGRATS. 4X the power :loser:



LoL, not a bad idea, but that's not what I meant. I meant each time a spark plug fires, part of that signal is directed to a convertor along with the others and causes the four indivdiual signals to one signal for the SOHC tach to repsond to. I saw autometer made this for the chevy lS1 engines, since they are distributorless, just like the SR20DET. This is how I managed my crackpot theory.


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