MazdaRx7Racer4Life

I just bought a new tach, an aftermarket one, because mine seems to be out of whack, it says im running 0 rpms in idle and i know im not, then it says im almost redlined at 3, and the car runs fine, so i had to go out and get a new one (new toy) but i don't know where to intall it, the intructions are for piston engines, it says to run it off the negative cable of the distributor, but i think we don't have A distributor, not sure about where i shoudl put it, any one know?

RETed

Each ignitor pack (leading or trailing) has a short wire with a female bullet connector on it.&nbsp Tap into this - I think you need to "configure" the tach to read a V8(?) signal, cause it fires every other revolution of the e-shaft.


-Ted

MazdaRx7Racer4Life

so wait, i tap into each one or i tap into any one of them, if its just one, which one?

RETed

Either or - most people tap off the trailing one, since it's closer to the firewall.


-Ted

MazdaRx7Racer4Life

Thanks a million bro, you saved my life, i didink't wanna wait until tommorrow, i wanted to get everything done today, since today is my birthday, today i am officially 16. A night out on the town with a new tach is nice for any little encaounters with the typical HONDUH or other racer. Thanks again

silverrotor

iTrader: (1)

But, If you tap It Into the Trailing Coil Pack you have to set It at 4 cylinder, as opposed to 8 cylinder for the Leading Pack.

RETed

I heard the signals are the same?&nbsp Can anyone else confirm?


-Ted

NZConvertible

The leading plugs are fired in wasted spark set-up, so the leading coil (one double post coil) fires twice as often as the trailing coil. The leading coil fires once per rev (like an 8-cyl) and each trailing coil fires once per two revs (like a 4-cyl). The trailing coil is closer anyway, so use that one and set it to 4-cyl.

MazdaRx7Racer4Life

so wait, which is leading and which is trailing?

MazdaRx7Racer4Life

hehe. nevermind, figured it out.