924Board.org

[Dutch924-racer]

A friend gave me an air fuel ratio gauge and a lambdasonde from a rally car.

I want to install it on my 931 car, this is an european car without an ecu/ lambdasonde.

I have two questions:

-what place did the lambdsonde originally sit at US cars (picture please)
-the lambdasone has 3 wires, two white, one black. I searched Google and twe black on is the signal, the white ones are for the heating. Can I put 12v one these ? I asume + or - doesn't matter as both wire are white?
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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

[Martijnus]

that has to be a narrowband O2 sensor... not sure how accurate you can use it with a gauge.

Can't tell you much about how to connect it. Could be 5v too instead of 12.
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"Rule: Turbo's make torque, and torque makes fun." (C. Bell)

924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment

[tuurbo]

I've got a narrow band - they're nice for light shows!

Gotta get me a wide band. I didn't install mine it was done for me when the mechanic had the car for another job.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[Dutch924-racer]

It is heated, so it shoud be wideband.

Narrowband has just one wire.
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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

[Martijnus]

[morghen]

if its from a rally car it should be wideband..i doubt they installed a narrowband on a high performance car.
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Supercharger and EFI kits
https://www.the924.com

[Dutch924-racer]

It is a 16 led display from KMS (van Kronenburg Motorsport). It came out of a Golf 3 Merwede springs-cup car with a Kronenburg tuned engine.

The rear of the display has +, - and signal wires.


Can anybody tell if the display is wide or narrowband ? Maybe i got the wrong Lambdasone with it.
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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

[Rich H]

A wideband sender is a complex beast with calibrations and so on, the senders are linked to the controllers which in turn control the gauges.

A simple lambda sensor (Narrow band sensors can have 1,2,3 or 4 wires) and a gauge (I made my own from simple IC components) is narrowband and of little use. It will tell you when it's rich or lean, but not be how much. The switch over point at 14.7:1 is accurate, but nothing else is calibrated.

I have seen a few expensively packaged (>£100!) narrow band sensors with led displays which can be duplicated for £20. A Wideband sensor costs a lot more but is invaluable is you are tuning.

The main question I have though is why bother?

I have an AFR gauge as I built it and it was easy to wire in from the wideband that feeds my Megasquire ECU for closed loop running. But it's little more than a light show. If you have CIS installed you can't do much about the tuning at differnet throttle and load positions as it's dictated by the air flow meter performance.
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[tuurbo]

I have a pretty much stock 931 and I use a 16 LED Edelbrock AF display mounted towards the windshield beneath the grill in the center of the dashboard - the one you can take out with your hands. It shows up reflected on the windshield at night. It's my own personal heads up display. It's not terribly useful to me.

When I set up the timing on my car, and frigged with the CIS hex key, I tried to ensure that basically the car ran fine at idle, and performed when I was on the street. I checked here and with Haynes and cobbled together a solution that left me with a very drivable and fast car. Once done, I found the AF gauge hooked up to the simpler O2 sensor, generally showed Green for Go under most driving conditions.

I presume my car generally runs a little rich. I've been satisfied with this state of affairs for more than a year or so.

What would disturb me with the primitive gauge and O2 sensor I'm using, is if the gauge generally showed or suggested 'lean' conditions, showing as Red on my gauge, when I hoof it (and need it to be a wee bit rich - as an old school believer that high performance cars can run a little rich and for our cars that's a better state of affairs than lean). Thing is, there are probably better indicators from the sounds your car makes during lean times, I would think - like ping. Or, while tuning, backfires on decel, hesitation and other indicators are useful to tell you where your car is at.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

[Dutch924-racer]

I asked my friend and the lamba i have is indeed the one from the car.

but I still have the same questions:

-what place did the lambdsonde originally sit at US cars (picture please)

-the lambdasone has 3 wires, two white, one black. I searched Google and twe black on is the signal, the white ones are for the heating. Can I put 12v one these ? I asume + or - doesn't matter as both wire are white


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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

[Smoothie]

Pending pictures that may or may not appear from someone.. (I don't have any.)
Rules for o2 sensor location are simple - place as far upstream as possible and practical (place where you can reach it for servicing), but after (downstream) of any collector joints (if seperate pipes from the manifold join into one with a collector), so the sensor has gasses from all cylinders passing by it. Of course if using a header, place it at the collector where all 4 pipes merge.
Generally they're located within 2-3 feet of the manifold.
With a heated sensor, you have more lee-way, but further upstream is always better.

The Bosch "Automotive Handbook" says that heated lambda sensors are better at reading the lean range, and of course they start reading sooner after startup, also due to the heating.

Don't happen to know their wiring, but I think you're guessing right that the white wires are for the heater, and polarity doesn't matter.
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"..it's made in Germany. You know the Germans always make good stuff."


'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

[morghen]

I've mouted it right after the turbo...on the top side.
http://www.924board.org/viewtopic.php?t=26709&highlight=lambda+probe
you can see there my instalation of the lambda probe. aldough people say that it is unaccurate...i dont know...mine reacts instantly to the gas pedal and generaly what the "LED" says..seems to be true...checked the plugs and they are dark brown...so its runing just a bit rich.

if it reacts instantly to the decell(fuel cut) and it reads what it was suposed to read...why wouldnt it react to an temporary lean condition?

any of the white wires can be + or -
_________________
Supercharger and EFI kits
https://www.the924.com