Tapping for multiple RPM signals........

[doyle4281]

I have a number items to install which require an RPM signal. Where can I retrieve this signal and what is the best method of branching it to multiple units?
Will branching the signal to multiple units weaken the signal to each unit? Will tapping into the wire interfere with the ECU? The car is an S14 and the engine is an RB25DET.........

[Corbic]

I have a number items to install which require an RPM signal. Where can I retrieve this signal and what is the best method of branching it to multiple units?
Will branching the signal to multiple units weaken the signal to each unit? Will tapping into the wire interfere with the ECU? The car is an S14 and the engine is an RB25DET.........

What are you actually trying to run?

[doyle4281]

What are you actually trying to run?


Well, my Eboos2 needs an RPM signal, two step rev limiter, turbo timer, and anything that may be used in the future. I am worried that if I simply just tap the wire from the ECU, and branch out to all these units, it will cause weak signals and harm to the ECU. I am wondering if there is a way to amplify the signal and use a junction area to branch to each unit.

[Junk240]

Try the negative side of the coil.
My Rpm gage was hooked up to that to get the rpm signal.
idk bout rb though.

[doyle4281]

I pretty much know where I can get the signal from, however I don't know how branching it off into multiple units is going to react. By adding much more wiring to that circuit, I would changing the resistance of that circuit.

[hisoka]

on a rb you must tap of the tach signal wire with a gold solder and a pretty decent wire, then tap as many things as you want.

and make sure you use a signal ground from your ecu or somewere.

[doyle4281]

Gold solder?

[510-SR20DET]

what he meant is make sure you use gold connectors, gold material is best for electric transfer.

[Ilya]

as long as you dont have miles of wire for the signal to travel through, you should be fine. Branching a signal means dividing the circuit into parallel connections, therefor voltage stays the same which ultimately means in theory that the signal should be the same at each unit you are trying to connect. It will be the current that is weaker, but that is not how the electronics interpret an RPM signal.

[bb4_96]

It's a signal that is being carried not an electrical load. Don't worry about it.

[efrain240sx]

what he meant is make sure you use gold connectors, gold material is best for electric transfer.

sorry but gold is not the best conductor; Silver is the best conducting material. Another thing copper is a better conductor then gold. The only advantage gold has over copper is that it doesn't corrode as bad as copper.

straight from my electrical book.
Conductor Rating (starting with the best)
1. silver
2. copper
3. gold
4. aluminum
5. tungsten
6. zinc
7. brass (copper & zinc)
8. platinum
9. iron
10. nickel
11. tin
12. steel
13. lead

[doyle4281]

as long as you dont have miles of wire for the signal to travel through, you should be fine. Branching a signal means dividing the circuit into parallel connections, therefor voltage stays the same which ultimately means in theory that the signal should be the same at each unit you are trying to connect. It will be the current that is weaker, but that is not how the electronics interpret an RPM signal.

absolutely correct.......I just was not sure if the different units I am hooking were going to become a load in the circuit. Great answer though.....

[510-SR20DET]

sorry but gold is not the best conductor; Silver is the best conducting material. Another thing copper is a better conductor then gold. The only advantage gold has over copper is that it doesn't corrode as bad as copper.

straight from my electrical book.
Conductor Rating (starting with the best)
1. silver
2. copper
3. gold
4. aluminum
5. tungsten
6. zinc
7. brass (copper & zinc)
8. platinum
9. iron
10. nickel
11. tin
12. steel
13. lead
Will you trade all your Monster gold cable for mine copper cable? :) enough said.

[hisoka]

i ment to say good solder hahahaha.

gold or whatever doesnt matter LOL