Board logo

O2 Lamda sensor type for AFR
RobBrown - 6/9/12 at 09:27 PM

In an attempt to try and get my Carbs setup, after advice on here about measuring AFR , i've installed a boss in the exhaust and have purchased and AFR meter.

Will any O2 sensor work? I noticed whilst browsing that there are multiple wires (1- many) involved on different models. They vary in price from £12 to £75.

Are they all M18 as well?

If I went down to my local breakers and just got a Mondeo Sensor, or even a new one from my local MotorFactor, would that be OK, and work with a new meter?

Thanks
Rob


woolly - 6/9/12 at 09:41 PM

which meter have you bought, you may need a wide band sensor VW 5 wire and a controller.


snapper - 7/9/12 at 05:28 AM

As I understand Lambda from a tin top are narrow band and a bit on/off for our application, realy need a wide and for proper setting up


Ben_Copeland - 7/9/12 at 05:46 AM

What afr meter have you bought???

Best to get innovate lc-1 wideband sensor, controller kit. Plus you can get matching gauge for a little extra


deezee - 7/9/12 at 07:36 AM

A production car O2 just tells if its running around OK or rich / lean. It won't tell you exactly what its reading, just those 3 choices. It makes it almost useless for tuning. The cheapo gauges for a production car O2 is just 3 LEDS in a dial arrangement. Utter toss.

For tuning a car properly its either a rolling road or you need a wideband sensor to go with a proper wideband afr guage. As mentioned AEM or Innovate are popular brands (its what my set up uses). This will cost around £150 all in. If you get a controller like an LC-1 you'll have to plug your laptop into it to see whats its reading, you can just get the controller built into the gauge for less and its easier to read.


RobBrown - 7/9/12 at 08:03 PM

It appears that I have cocked up then, as my meter arrived today and it is a narrowband one, with only a single wire feed.

It has a digital readout as well as a dial - if that give more confidence over it being more than just a too rich, too lean jobbie

Today I ordered a Bosch LSU4.2 sensor (wideband). The two are not meant for each other - even I can gather that!

Bu&&er

Options
1. Stick the meter straight back on ebay
2. Get a cheap narrowband sensor, from my local MF in the morning, and see if it sorts out my immediate Too Rich or Too lean at WOT question!

Considering it's the weekend and I'm itching to get something done!


paulf - 7/9/12 at 08:42 PM

You should be able to get an idea of whether it is to rich or weak but not by how much, I used a narrow band sensor with mega squirt and managed to get the car to run reliably with it but then changed to a wide band and managed to map the car to be more economical as well as perform better.
You may be able to drive the gauge from a wide band controller output set up to emulate a narrow band although if t has a digital read out as well as bar graph it may be a wide band compatible unit anyway.You say you ordered a bosch 4.2 sensor but you will also need the controller to go with it either an innovate , AEM or similar unit.
Paul

quote:
Originally posted by RobBrown
It appears that I have cocked up then, as my meter arrived today and it is a narrowband one, with only a single wire feed.

It has a digital readout as well as a dial - if that give more confidence over it being more than just a too rich, too lean jobbie

Today I ordered a Bosch LSU4.2 sensor (wideband). The two are not meant for each other - even I can gather that!

Bu&&er

Options
1. Stick the meter straight back on ebay
2. Get a cheap narrowband sensor, from my local MF in the morning, and see if it sorts out my immediate Too Rich or Too lean at WOT question!

Considering it's the weekend and I'm itching to get something done!


MikeRJ - 7/9/12 at 08:44 PM

quote:
Originally posted by RobBrown

2. Get a cheap narrowband sensor, from my local MF in the morning, and see if it sorts out my immediate Too Rich or Too lean at WOT question!




This won't work very well because need to run somewhat rich at WOT, but a narrowband won't tell you how rich you are (at least not with any sensible accuracy). In fact a narrow band isn't even very good for telling you that you are running at stoich, since the transfer function is so steep in that area (i.e. a very small change in AFR gives a big change in the output voltage).

In a production engine using a narrowband sensor the ECU treats the sensor as a switch, so it's either weak or rich. By trimming the mixture in the opposite direction to what the sensor is saying, you constantly toggle from rich to weak and back, so on average the mixture stays around 14.7:1.


RobBrown - 7/9/12 at 09:20 PM

So...

Does the O2 Sensor plug into the controller and the controller plug into the meter then? I thought the sensor went straight to the meter!


RobBrown - 7/9/12 at 09:23 PM

Would something like this be OK:

Innovate AFR DB-Blue Kit (Blue LEDs, LC-1 and O2 Wideband Sensor) PN 3795 856428037957 | eBay
INN-0002 ebay listing


or if I only got a controller (INNOVATE LC-1 WIDEBAND LAMBDA O2 CONTROLLER 3744 | eBay) would this link directly into my laptop, meaning I wouldn't need an external meter at all?

[Edited on 7/9/12 by RobBrown]


Ivan - 8/9/12 at 04:53 PM

I am using this Innovate Gauge on my Cobra and despite having only run it for about an hour am very impressed with the info it's giving re mixture strength - it's very sensitive and responsive but of course I have no easy way of testing it's accuracy.

http://www.innovatemotorsports.com/products/MTXL.php

It does show that in most cases the car is running way too rich (12.3:1 when cruising on a trailing throttle) - born out by the less than stellar fuel consumption of 4km per liter.

The only time the AF ratio goes any where near 14:1 is for a fraction of a second when accelerating hard and the accelerator pump shot hasn't caught up with the demands of the motor, then it settles back to around 13.2:1 with the foot flat. But off course given the rate of acceleration I can't keep my foot buried too long on public roads so will wait for some track time to get better data and possibly link it to a logger as well.

I will soon look at some jetting changes in the Holly.

Re- your query I think any Innovate product is pretty good.


paulf - 9/9/12 at 09:30 PM

In your case I would get the gauge as you can then stick it on the dash and see in real time what is happening, as you have carbs you would find logging it with a lap top to be not of much use unless you also fit a throttle position sensor so as you can relate revs and throttle to the mixture.It is not very easy to look at a laptop perched on the passenger seat whilst driving fast and I now data log and interpret latter.
Paul

quote:
Originally posted by RobBrown
Would something like this be OK:

Innovate AFR DB-Blue Kit (Blue LEDs, LC-1 and O2 Wideband Sensor) PN 3795 856428037957 | eBay
INN-0002 ebay listing


or if I only got a controller (INNOVATE LC-1 WIDEBAND LAMBDA O2 CONTROLLER 3744 | eBay) would this link directly into my laptop, meaning I wouldn't need an external meter at all?

[Edited on 7/9/12 by RobBrown]


coyoteboy - 10/9/12 at 02:00 AM

Just to clear up any confusion... Most older cars and some recent have a narrow-band lambda sensor. These output a nastily bipolar signal (lean or rich, they don't really hang around near stoic because that's not how they were designed to function). A gauge on one of these is borderline pointless, though they can be used for some ECU tuning where your software can take account of all the riches and leans and attempt to average them out. No good for carbs.

Widebands are on many modern vehicles and are generally 5 wire devices. They require a controller (which does both heater control and ADC among other things) and the quality of the controller is important as it's calibration and correct operation is what gives you the correct readings to send to a gauge of your choice. If the heater control is a bit dodgy for example, your readings will be off. It's a fairly complex bit of kit.

I use the LC-1 and directly plug it into the ECU but you could use the second output into a generic 0-1v or 0-5v gauge for a readout. This will give you, with luck, an accurate readout across the AFR range and with update rates in the millisecond range.

[Edited on 10/9/12 by coyoteboy]