I recently picked up a data telemetry device that has built in g sensors, yaw and gps. It also has the ability to input analog and digital data directly to it. Seeing as it currently does not have the ability to interface with MUT or ODBII I wanted to look into reading RPM (for sure), TPS and Boost with it. I currently have a 3 bar installed and I presume that it is a linear voltage based on the amount of PSI in the system. My question is pretty simple for anyone whos connected those kinds of things. Can I just tap the wire according to the ECU chart (#58 for RPM for instance) and just run it straight to the data logging box, or do I need to do something more fancy? Also, should I look into getting the AMS harness extension, or just be careful and splice into the existing harness via a T-Tap or soldering a wire. Any help would be appreciated, thanks!

 

Splicing into the harness at the ecu is pretty easy. You can pull signal off all the stock ecu sensors except the knock sensor ( its a shielded wire with high sensitivity so you don't want to mess with the current even a little).

The tach output of the ecu requires either the stock instrument cluster to be plugged in, or to wire in a high resistance pull down circuit. Without it, you won't get a signal.

 

Awesome, thanks for the quick response. The stock cluster will remain in so that's good to know.

 

What kind of datalogger do you have? Are the analog inputs differential or single ended?

 

I use several different devices. We have a race technologies dash2 digital dash, and a dl1. Also use the Zeitronix boxes to their full extent. Last we also have a traqmate we made plug and play. The dl1 uses single ended analog inputs. So does the Zeitronix but it only has two inputs. The dl1 has 8 if I remember correctly. I've also used the edelbrock quick data system extensively which had 32 inputs.

 

The Edelbrock system sounds pretty solid.

I should have directed my question a bit better. I was more curious about the OP's unspecified datalogger so we could provide some more specific help.

 

My bad, thought I had posted that. I'm using a new product that was recently released called Racecapture Pro. http://www.autosportlabs.net/RaceCapturePro So far a pretty good product, their software has a way to go still but its promising. I had also contacted them on their forums and their response was basically:

"For tapping into the tach signal: there are two different kinds of signals present on ECUs. Some systems tap right into the ignition coil primary circuit, which has a high 400-500v high voltage spike which can damage electronics. RaceCapture/Pro is not designed to handle such an input as the inputs are protected to 40v, so do not connect the tach signal without knowing the source.

We have designed (and are testing) a small opto-isolated adapter board for buffering and conditioning that signal. More information on that coming soon. "

I am currently assuming from what I've seen, that ours is not the kind above since it is outputted by the ECU for the tach on the cluster correct? (And I noticed I made a typo, RPM is #45 for an Evo 9). I'm trying to recall where I saw that it specifically labeled that pin as out and not in as the doc on http://www.evoscan.com/manuals/Evo%2...U%20pinout.pdf does not specify and just lables it as RPM.

Edit: found the link that specified it as out: http://www.roadraceengineering.com/e...-ecuwiring.htm that was for an 8 though which was pin #58.

 

Correct, the tach signal is for the instrument cluster so it will work with your electronics.

 

Thanks =)

 

How do you like the Zeitronix products? Sorry to thread jack, PM me if its out of place.

cheers

 

It's the best bang for your buck wideband system out there. I use it to tune every car that comes through my shop!

 

We also use Zeitronix (and AEM) and are very happy with both companies!

Dan

PS We do no solder any wire connections, we use uninsulated butt connectors and heat shrink. Solder can crack under vibration.

 

A proper solder connection should be just fine in almost all cases, especially on a relatively flexible cable that will dampen most of the vibration anyway. But butt splice connectors and heatshrink are a good alternative if you don't have the proper flux, iron, and solder to make a quality joint.

All of the components on your ECU PCB are soldered down to a rigid PCB that sees more vibration than a relatively flexible cable.

 

A poorly soldered joint is just as unreliable as a poorly crimped butt connector.