rpm and speed wiring

[Dogo]

Hi all,

I finally re-installed my Apexi RSM in my car. Its been sitting in its box since i took it out of the old car. Mounted in the same place as last time. I love it there



Anyway.

This time, I found a much better time to wire it which I thought I'd share with you in case someone finds it useful one day.

The RSM needs 4 main wires , rpm, speed, ignition power and ground.

Power and ground are easy, Ive had a ignition triggered circuit setup for a long time to run various things.

The Apexi wiring guide says to splice the rpm and speed wires at the ecu and contains a manual with heaps and heaps of car's ecu pinouts. As per usual, the BA isnt mentioned and so with the last car I worked out the pinouts with the help of a mazda service center.

Anyone who has seen the ecu plugs knows this is an absolute pain in the ass!

This time I had the workshop manuals as a reference and worked out that the dash dials are a much better source of the rpm and speed signals. In the case of speed , it gets the pulse first, and then sends it on to the ecu.
The dials are also 100% easier to get to and work with.

What makes this even easier is that on the back of the dials is a plastic circuit board which is very well labelled and has screws inset.
Fantastic ! no cutting / splicing / soldering at all required. I just strip a bit of shielding off the RSM wires and use the screws as terminals to the circuit board. easy as pie and took like 10 minutes.

unfortunaly I didnt take photos although I meant to.

from memory the pinout of the dials is 2E is speed output ( to the ecu ). I think it was labelled 'SP+' on the circuit board. The RPM output was 2D I think. It was labelled something like 'P' maybe.

Either way, i connected my wires to the screws labelled 'OUT' behind the speed and rpm dials. Since the dash also has ignition triggered power, i used it to make install/uninstall easier. It came from screws connected to B+ and -

If any1 has a photo of the back of the dials cluster I can point out which I used.


So if ever u need a speed or rpm signal, use the dash, not the ecu

[Rupewrecht]

it's a bit small, but you might be able to use it

[ROB-80E]

Scuse my ignorance guys, but what do the RSM actually do? I've never looked into the ApexI range of products....


P.S.
Yes I am in a lazy mood ops:

[sik astina]

Yeh thats where i got my Speed wire from for my Turbo timer (inbuilt G-tec).

I have a close up pic of the dials. will put it up as soon as i find it.

[sik astina]

Found it.

[Dogo]

the RSM ( rev speed meter ) is like having a very fancy g-tech pro permanently wired into the car.

Most days I leave it monitoring speed and revs but it will also monitor volts, distance and G forces forwards/backwards and left/right. In monitoring mode itll give u a number readout, graphs, or dials. It has a number of different ways to plot graphs especially against G-force and rpm.
It can also record and playback its readings. and also record peak readings

as well as monitoring it will do time/distance runs - so it does qtr mile, lap splits etc as well as speed eg 0-100. You can configure the speed and distance to whatever u want and it keeps records top 10(5?) runs.

by entering the weight of the car it can also capture power output in hp, kw etc and also stopping power and deceleration caused by gears etc.

it also has configurable outputs which can be hooked up to various things like triggering a shift light, changing ems maps, boost settings etc. and it can also warn you when u get over set configurable limits such as redlining and speeding

that make sense ? It doesnt change anything - doesnt make the car faster etc, but its handy to have. It can also bypass speed limiters on jap cars.

[Dogo]

http://apexi-usa.com/meters_revspeedmeter.asp

[Dogo]

the plug in sik's pic is the one in the middle ( directly under the black tube holding my wires )

[platypus]

alright boss.... what are the other leads you have in that loom for?

[Dogo]

wire colors there are :

red - ignition power
black - ground
yellow - rpm
purple - speed

the other wires in the rsm loom are used for different configurations

there will be an rpm and speed output ( used to bypass the built-in speed or rpm limiters in some cars ) as well as outputs which are triggered by reaching configurable settings. such as turning a shift light on when reaching over a certain rpm , boost scramble activation etc.

i think there are also different inputs which are needed for a few cars with odd setups.

the RSM also has a seperate G-force sensor which has its own plug and doesnt need any fiddling with wires.

[chipa]

I want one!

How much are they worth?

[Dogo]

havnt looked at prices for a while to be honest

$3-400 maybe ?

[Rupewrecht]

you can get them for as low as $250 if you look hard enough,m but it's been a long while since i looked at prices.

Dogo - so you've actually installed the G sensor after all this time?

[Dogo]

i need to extend the wires on the g-sensor because I want to mount it on the chassis behind the gearstick.

so not yet, but soon

i hope to check/calibrate the power readings from the RSM against a dyno so that I can trust its figures

[chipa]

hmmm. here's one on ebay: Apexi RSM

going for $255 with G-force sensor.

[pharkn-kb]

hehe i have one of these now.. all i need to do is wire the bugger in

[cgunther]

An alternate place to mount the gauge is on the dash as close to the windscreen as you can get it. I find its a bit further away, and easier to glance at. That said, I don't know how legal it is where either of us have mounted the RSM. I also wired in a hidden switch onto the positive lead so it can be turned off...

Can just see it in this photo:



Also Autometer will be releasing their equivilant soon. Seems to be pitted against the G-Tech.
http://www.ringwood.autobarn.com.au/...=122&history=1