12 volt source for AFR gauge?

chrenan · 01-29-2011, 07:34 AM

Hey Guys,

I'm installing an innovate mtx-l wideband setup to
monitor AFR values. Where does everyone pull their
12 volt source for these in the cabin? The manual
says the stereo power is not ideal. Anything else
convenient?

Paulyy · 01-29-2011, 07:59 AM

only reason the radio isn't ideal is because the WBo2 uses 10A and the headunit will use 10A also and the fues in the fues box is 15-20A i have a wire off my ignition on ACC (first turn) to run m LM-2 and it's also fused with a 10A fuse.
do not use cig lighter to wire it, it's always on.

running_cold924 · running_cold924's Garage

i mounted mine below the radio. I also found a spare harness that wasn't plugged into anything and tested the wires on it. i found one that had power with key on only and used that one to power mine (AEM). no problems so far...

chrenan · 01-29-2011, 01:20 PM

Thanks guys. I'll take a dig around and hopefully I'll find something. I can't stand wiring, its not great fun for the colour blind like me.

running_cold924 · running_cold924's Garage

just use a test light and find one that's hot with the key on.

carlege · 01-29-2011, 09:05 PM

Chrenan, I feel your pain.. color blind here also

PrimeMvr · PrimeMvr's Garage

I'm looking at one of these also for my '87 930. Did you hook up the analog out to simulate the NBO2?

Anyone know how to positively ID what O2 sensor this is? I've only had this car for a few months (my first PCar) and some of the update history is sketchy. I want to be sure I know what I have before I make changes based on assumptions. It has 3 wires that appear to be in a stock harness. I'd like to replace this with a WB, but I don't want to disable the lambda circuit.

The harness connector

Thanks,
Steve

chrenan · 02-07-2011, 07:30 AM

Steve, let me first say I have zero knowledge on the 930!

OK, now that that's out of the way. I'm still going to run my stock O2 sensor for the narrow band output, its brand new anyway. Once I get my new MAF setup up and running and I'm happy with AFR numbers I'll try to generate a NB signal from the mtx-l.

Your O2 sensor just looks like the stock Bosch NB that most Porsches of that vintage run. In fact, the harness plug looks identical to the one on the 951.

One problem with just replacing the NBO2 with a WBO2 is the mounting location. I understand that a WBO2 isn't as tolerant to heat. Most 951 guys mount their WBO2 further downstream than the NBO2 to get a bit more distance from the turbo and its associated heat. Not sure what the mounting situation is like on the 930, might not be an issue in your application...

choinga · 02-07-2011, 09:58 AM

I wired mine into the DME - several switched 12v and ground wires in there to choose from. I had mine apart and was already soldering into the DME installing my Vitesse MAF, so it made sense. I also just couldn't bring myself to hook that thing up to the same circuit as my radio - giant birds nest in there and didn't want to risk it. The DME harness is the ideal spot if you can swing it.