AEM Wideband O2 gauges
 

I highly recommend having a WBO2 gauge in any of the 911 air cooled cars but not all gauges are created equal.

Always use the more modern style gauges that utilize the LSU4.9 sensors and not the older LSU4.2 sensors. The LSU4.9 sensors NEVER need free air calibration.

The product line I really like is the AEM gauges:
Wideband UEGO Air/Fuel Controllers | AEM

They have both digital and analog style gauges as well as a really neat new gauge that actually uses a smart phone over WIFI. The phone connects to the WIFI gauge controller and the AFR data is displayed on the phone, no wire connection between phone and gauge. I have had several folks tell me they don't want modern gauges installed in older cars, I think the WIFI gauge solves this problem.

Here are the AEM gauges:
Digital and cheapest, plus it's the LSU 4.9 better sensor:
Aem 30 4110 Wideband O2 Uego Controller Air Fuel Ratio Gauge Kit Bosch 4 9 LSU | eBay
Same as digital but with Analog gauge, older 4.2 sensor:
Aem Analog Face Wideband O2 Uego Gauge Sensor Kit Air Fuel Ratio afr Meter | eBay
The WIFI version, more expensive, older 4.2 sensor:
Aem x WiFi Wideband O2 afr Sensor Uego Kit Wireless Monitor Controller | eBay

The AEM product for the money is very high quality and has excellent heater control for the sensor. Heater control is important for the sensor's longevity.
I also like the TechEdge products WBo2.com WIDEBAND AFR/LAMBDA (Tech Edge) but these products are for tech savy folks only! Very powerful but not easy to setup.
Plenty of other decent brands around, just be sure you get a LSU4.9 sensor gauge.

Hope this helps others looking at adding a WBO2 in the cockpit.

I've got this one in my car, has USB for datalogging and will cut boost if you go lean:

Wideband Failsafe Gauge | AEM

Yes, this one is also very nice with added features. I assume you are happy with it?

Also this gauge can log and includes RPM input, correct?

Sal, I got the AEM WBO2 gauge per your recommendation. Waiting to install it with my SSIs. Then, your MAF and chip!

Steve

Are the cables on these enough to reach from the O2 location to the cabin for the guage? Or is splicing necessary?

If you place the gauge in the center console or below the ash tray and run the cables straight shot to the O2 sensor they reach.

Using Wideband O2 instead of CO meter
 

On a CIS car can I use a Wideband O2 sensor instead of using a CO meter to check and adjust my mixture? O2 is measuring fuel to air ratio, and CO increases with a richer mixture, so am I getting essentially the same information by using either? The O2 sensors seem cheaper and easier to come by.

Yes, you can use a WBO2 to setup a CIS car. I have a cross ref document for CO to AFR.

Here's a few values:
%CO AFR
----------------
0.1 14.72
0.2 14.54
0.3 14.42
0.4 14.34
0.5 14.28
0.6 14.23
0.7 14.21
0.8 14.17
0.9 14.15
1.0 14.11
1.1 14.09
1.2 14.04
1.3 14.01
1.4 13.98
1.5 13.94
1.6 13.89
1.7 13.86
1.8 13.82
1.9 13.80
2.0 13.77
2.1 13.73
2.2 13.69
2.3 13.63
2.4 13.59
2.5 13.56
2.6 13.54
2.7 13.49
2.8 13.45
2.9 13.41
3.0 13.38

I think base mixture on the CIS car is set at around 14.2AFR +/- 0.2

AFR to CO
 

Great, thanks for the info. Looks like I need to get an O2 sensor.

Bently
 

The Bently manual says the idle mixture CO% should be 1.5 to 3.5% at 950 +/- 50rpm, so that would be 13.94 to 13.2

Please excuse my ignorance (and laziness). Can you explain where the wires enter the cabin and what the place is to grab power from?

My wires come in with my wiring harness, and run under my drivers seat. I temp mounted my analog gauge in the centre console, but i am now deleting that, and will try to place it with two more gauges where the radio was.

Mine is ground in the passangers floorboard screw, and links into my ignition. I forget the other spot.

Well worth the money.

I like the Daytona-Sensors instrument sold by PP a lot better. Very well built, very reliable and great customer support. Very good data logging and software as well.

if you have CIS, MFI, or carbs.....you need a good AFR gauge

Why is the LSU4.9 so important? Calibration take all of 30 seconds. this sounds like an ad for AEM.

I had a LC-1 in a turbo'd Miata project a while back. It needed free air calibration very often, even with a new sensor. It was a complete PITA.

Thanks!

Just placed my order. Been putting this one off for a while.

Agree with taking the sensor cable to the rear of the car via the existing wire harness just below the rear LHS seat, the wire will fit into that existing hole in the 84-89 cars.

The gauge then needs power and I recommend extending the power and ground lines up into the front truck and then ground and power it at the fuse box. Tap power into an existing fuse lug, find a fuse with power in 'RUN' like the Cigar Lighter fuse #6. I recommend this fuse since most never use the lighter and it has plenty of spare current capacity. Tap the hot side of the fuse, the side that has power with the fuse removed. Then put a 10amp inline fuse on the line that feeds the gauge.

Or you can simply power the gauge directly from the cigar lighter in the cockpit, I just don't like cutting or tapping wires so I recommend the fuse block as a better approach.

I've also had folks turn the gauge into a temporary install to move in and out of other cars. Some put a cigar lighter adapter on the power/gnd lines and simply plug into the lighter. You can also put the gauge in a temporary 2" pod and velcro it to desired location. Then run the line to the sensor out the rear side window and tape it to the side of car with blue painters tape. Of course this is only for temporary quick install. You can also put alligator clips on the power/gnd lines and power it from the fuses in the engine bay and have the gauge right at the engine bay, this works well if you just want to use the gauge to set base fuel mixture in a CIS or Motronic car.

My personal in car gauge is mounted in a small 2" round pod and sits on the very far LHS of the dash against the pillar. I like it here because it's in my line of site at all times. The pod just sits in the corner and held in place with a tinny piece of velcro to the windshield post.

Agree! The LSU 4.2 sensors often need recalibration, the LC-1 often needs recalibration and you MUST take the sensor out of the exhaust stream to calibrate it, you can not calibrate the gauge with the sensor still in the bung. Huge pain!

Here's some pics of cars with the gauge in cockpit:
My personal car:
http://forums.pelicanparts.com/uploa...1450447045.jpg

This is one in the center console:

http://forums.pelicanparts.com/uploa...1450447174.jpg

Maybe others will post more pics.

Hey Sal, does your CO readings account for E10 gas? Good info there!