aftermarket tach options

[Shift]

So I need a tach since I dropped a rb into my 89 S13 and there doesn't seem to be too many sources of info for aftermarket tachs for rb's. But options I've found so far are:

1. splice a 10k resistor into pin 7(tach signal) and pin 49(unit power) then the signal from pin 7 should be upped to 12v and work aftermarket 12v tachs

2. get an ignition pickup that you have to tap into power for coil #1 then take signal wire from pick and wire to tach

3. splice a 470ohm resistor between the 12v and signal pin on any 12v tach and wire normally


I'm pretty much wanting to stay away from option #2 because it's a lot of money just for a tach.

Anyone else had any luck with these options/had to get an aftermarket tach?


Thanks.

[Skym]

Don't know much about the wiring side, as it's not my forte. But sort of understand some of what your saying with resistor for power conversion to dash (ages ago I've seen how it's wired in the back of a engine manual for S14 and seen where it goes to, from ECU plug, dash).

Just some suggestions, probably would be much easier for people to understand if had wiring diagram of how you think it should be wired on back of dash (photo or similar) and have pinouts of ECU plugs for both engines. Also what RB engine?, i.e RB25DET, RB20DET, etc.

A fairly cheap option as far as aftermarket ECU's go, could be a Link ECU with dash -

http://www.linkecu.com/products/TuningTools/DisplayLink

Or Vipec ECU.

[Shift]

Alright well here it goes:

Most aftermarket tachs that are available from lordco, jb, crappy tire are meant for ignitions with distributors (as far as i've seen anyways).
Now the rb's (in my case rb20) uses a distributorless ignition system "DIS" that is coil-on-top referring to coilpacks on top of spark plugs.
Added to that most tachs are meant for a 12v feed whereas the rb ecu only puts out 5v.

Wiring diagrams don't really matter. There's a ground, constant 12v and signal source to the tach and a 5v tach signal wire that comes off the ecu.

So the resistor would tap into the 5v tach signal from the ecu as well as the unit power wire to up the voltage signal to get it from 5v-12v so it can be picked up by the gauge.

Pretty much just looking for some help/feedback from ppl that might have replaced their tach because the bottom line is my stock tachometer will not work with the engine.

Although it has crossed my mind to rock nistune and a netbook for a dash...but that's just wishful thinking