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 Post Posted: Fri Sep 22, 2006 10:00 am 
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Sam wrote:
Most lambda sensors give out 0.5 volts at lambda 1. (approx 14:1 afr)

useally 0.2 volts is very lean and 0.8 volts is very rich, now you should be able to read them with a voltmeter.

Ideally you would need to calibrate them against a afr meter or even a Co meter. once you know what volts you get at each value you could use a cheap volmeter with the scale marked for the values or even a plain old multimeter.

bear in mind that most of them are heated and if you use a non heated one it will need to get up to temperature before you rely on it.


The unheated ones have a min of 2 wires as some have one. The one wire unit use the exhaust for a ground (later found out that this was not a good idea) so they produced them with there own ground =; Barry

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 Post Posted: Fri Sep 22, 2006 10:26 am 
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I guess whether one is heated or not is irrelevant for a race car as that sensor isn't really controlling fuel mix like one on a passenger car would. I'm assuming they heat those so they can control fuel mixture at cold startup, something we racers don't have to worry about.

Correct?

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 Post Posted: Fri Sep 22, 2006 10:29 am 
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Ken0069 wrote:
I guess whether one is heated or not is irrelevant for a race car as that sensor isn't really controlling fuel mix like one on a passenger car would. I'm assuming they heat those so they can control fuel mixture at cold startup, something we racers don't have to worry about.

Correct?


That's right as the heated ones are big $$$ as we know you can relate too! =; =;

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 Post Posted: Fri Sep 22, 2006 10:39 am 
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O:)

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 Post Posted: Fri Sep 22, 2006 12:11 pm 
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the reason for the heater is more to protect the delicate ceramics from thermal shock.

a droplet of condensation getting onto the ceramic could cause it to crack, the heater helps to overcome it. as a side issue the sensor would also not be as accurate as it could be until it is up to operating temperature the heater element helps along with the hot gases to acheive it quicker.

you'd be surprised at some of the things that have been done over the years to get the cat lit off asap. roads engines especially are very dirty in the first few seconds of running. hence the need to get control as quickly as possible.

I'd recommend a heated (hego) anyday despite the cost and to turn it on a couple of minutes before the engine is started. it'll live longer especially in a race engine.

As to the sensor in each port, I've used one, it was in a 40 valve v8 on a fully mapped sequential injection engine. as the build was of high quality you could assume each cylinder was exactly the same in regard to afr, there would have been minor differences at idle (1800rpm) due to leakage round the throttle slides but as the engine would only be at this condition for a very short time it was ignored.

As your only concerned with hot engine performance then I'd make sure it was hot before you fit the sensor.

going back to the previous posts I did say on another that the 8 egt's and 2 ego's would be the best combination. I guess chuck's post showing one egt down for a couple of seconds backs that up.

to be honest if you have good friends that you race with on a regular basis buy a decent set up between you and each buy a sensor, you only need it for set up or if you have a problem.. one of the ones I recommended at the start of this post becomes low $ when you share it between a few.. you could even afford to buy 2 and do both banks.

on another note if fitting it in a collector then make the seal between it and the primaries as good as possible, its not much of a leak that will throw the reading off.. to prove it when you have it running drip a few drops of gas or alky on the joint and watch that meter move...

I'll stop now ... =; =;

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 Post Posted: Fri Sep 22, 2006 12:30 pm 
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Sam wrote:
the reason for the heater is more to protect the delicate ceramics from thermal shock. A droplet of condensation getting onto the ceramic could cause it to crack,


Well, that lets my alky engine out! That thing will actually drip water (condensate) for the first heat cycle. Evey time I start it for the first time it will drip water out of both exhaust pipes until it get's hot.

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 Post Posted: Fri Sep 22, 2006 12:33 pm 
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Awesome post Sam!!!

You sound like you been around these O2 senors quite a bit


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 Post Posted: Fri Sep 22, 2006 12:47 pm 
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Tom McDunnah wrote:
Awesome post Sam!!!

You sound like you been around these O2 senors quite a bit


Thanks Tom, and yes I've used a few in my time and still do.. it goes with the job..

Just happy to post it as it starts to repay some of the good advice I have got from here from these guys

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 Post Posted: Fri Sep 22, 2006 1:29 pm 
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Ken0069 wrote:
Sam wrote:
the reason for the heater is more to protect the delicate ceramics from thermal shock. A droplet of condensation getting onto the ceramic could cause it to crack,


Well, that lets my alky engine out! That thing will actually drip water (condensate) for the first heat cycle. Evey time I start it for the first time it will drip water out of both exhaust pipes until it get's hot.


Put the sensor in the top then Ken..... I did say to get it warm before you fit the sensor for this very reason.

I'd also recommend some very high temperature grease on the treads of the sensor (only the threads) to enable it to be removed easily.

most of them use the same thread as a pinto spark plug 18mm ?? although i have seen them with a much smaller thread in some applications.

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 Post Posted: Fri Sep 22, 2006 2:45 pm 
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Yeah Sam but there’s no guarantee that condensate that’s blown down that pipe wouldn’t hit that thing, even mounted on top of the collector and my car isn’t real easy to get to like yours is. I guess I’ll just continue to run without one of those as it’s just too damn much trouble to put one of those in and then take it out every time I go racing. There’s already enough crap to keep up with without adding something else. Yup, old, fat, ugly and lazy! =;

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 Post Posted: Fri Sep 22, 2006 6:48 pm 
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Beretta wrote:
Now that is awsome!!! Chuck did you find the problem?? plug wire or?? :-k Any news yet???Barry

I did a littler work on the car last night, the cyl 2 plug wire was backed off some, the boot holding it in place. I changed the spark plug just to be sure. I guess we'll see...

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 Post Posted: Fri Sep 22, 2006 6:52 pm 
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Going racing tomorrow Chuck??? =;

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 Post Posted: Fri Sep 22, 2006 7:14 pm 
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Beretta wrote:
Going racing tomorrow Chuck??? =;


Was al ready to go this afternoon but the weather wasn't. I was going to see what was going on at one of the other tracks but it looks like they're predicting some more bad weather, possibly severe.

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 Post Posted: Tue Oct 03, 2006 6:17 pm 
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Don't know how I missed this one.

The NGK AFR pic Sam posted is the exact one I own and used to get a baseline tune on my car. I did exactly as was mentioned above and dialed it into 12.5. Since then I have jetted up twice and am at 72/80. The last jet up was this past Saturday and boy oh boy did it ever make a difference.

In my case I just needed a reliable source so I could be sure I wasn't going to lean out a cylinder.

Oh, and I run mine with an on/off switch and turn it on a few seconds after I start the motor. Other than having to calibrate it every time because of the race fuel it's fun tool. And yes it's an 18mm thread. It also gets removed when I'm not tuning.

Jeff

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