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Microtech How precise is the A/F reading?

Old Aug 2, 2005 | 01:46 AM
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How precise is the A/F reading?

How precise is the A/F reading on the screen, with a narrow band oxygen sensor connected?
Could it be used for tuning, or is it just a "fun" onscreen function?
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Old Aug 2, 2005 | 01:07 PM
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A narrow band O2 will tell you if you are lean, or rich...but it will not tell you by how much. I would never use one to tune a rotary. I'm an old Megasquirt guy, so here's a clip and pic from the MS manual that I like to refer to.
With a narrow band sensor, we can really only tell for certain whether we are rich or lean, but not by how much. If you look at the graph, you can see that for a narrow band sensor, the 12.5:1 AFR required for maximum power can give O2 voltage from 0.8 to 0.95 (depending on exhaust gas temperature), yet this same range of O2 voltages can indicate mixtures from 10:1 to 14.5:1. So we cannot use it reliably to set mixtures for full power. With a wide-band sensor, 12.5:1 corresponds to 2.08 volts, and 2.08 volts means 12.5:1. Thus there is no ambiguity over AFR and voltages. We can measure any mixture in the range we are likely to use, from full power through to maximum economy.
http://www.msefi.com/msinfo/manual/wbvolts.gif
Hope this helps!
-John
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Old Aug 2, 2005 | 03:27 PM
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Thanks a lot!
Then I just have to buy the Zeitronix I have wanted for a long time....
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Old Aug 3, 2005 | 10:37 PM
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No problem, glad I could help!
Now I'll shamelessly plug my favorite wideband company: Innovate Motorsports! Check out www.innovatemotorsports.com! ;-)
-John
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Old Aug 4, 2005 | 03:21 AM
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I have been looking at that.... But no! I like to have the EGT readings on the same display! That's one of the nicest things with Zeitronix...
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Old Aug 4, 2005 | 11:53 PM
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Originally Posted by TwistedRotors
No problem, glad I could help!
Now I'll shamelessly plug my favorite wideband company: Innovate Motorsports! Check out www.innovatemotorsports.com! ;-)
-John
Yes, their new gauges work flawlessly, and look awesome!
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Old Aug 12, 2005 | 04:34 PM
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even the wideband on the microtech isn't very accurate.
the last one i did was a FULL point off!!!
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Old Aug 14, 2005 | 06:09 PM
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Originally Posted by GUITARJUNKIE28
even the wideband on the microtech isn't very accurate.
the last one i did was a FULL point off!!!
what model ecu and what sensor/controller was it using?"
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Old Aug 14, 2005 | 09:34 PM
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lt12, microtech controller, 6066 sensor.
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Old Aug 15, 2005 | 12:56 AM
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id say your sensor was faulty,

i use one of them every day of the week and i have compared them to innovate, motec, autronic and they are identical,
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Old Aug 15, 2005 | 12:51 PM
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are they self-calibrating?
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Old Aug 15, 2005 | 09:01 PM
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dont have to free air calabrate as such like the innovative,

just install the sensor in the bottom of the dump pipe not directly behind the turbo, these 6066 sensor do not like heat, if you get them hot they will not read well at all

Dale
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Old Aug 15, 2005 | 09:07 PM
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at least they aren't as bad as the 7057's.
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Old Aug 30, 2005 | 06:22 PM
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quick question guy's my.. lt12 calls for a lsm11 wb o2 I believe, those run 275 if I'm not mistaken.. and I see that you can find what you call the 6066 sensors for cheap. can these 6066/7057 sensors be run in my lt12 as well... cheaper is better only if they work well...
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Old Aug 30, 2005 | 06:42 PM
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i didn't know there was an lsm11 option... the only one i've got from microtech came with a 6066.
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Old Aug 30, 2005 | 08:41 PM
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Originally Posted by astrochild7
quick question guy's my.. lt12 calls for a lsm11 wb o2 I believe, those run 275 if I'm not mistaken.. and I see that you can find what you call the 6066 sensors for cheap. can these 6066/7057 sensors be run in my lt12 as well... cheaper is better only if they work well...
no you cant use the 6066 with that ecu, you can only use the LSM11

Dale
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Old Aug 30, 2005 | 10:25 PM
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oh hold up...

i got the controller. are you talking about the built-in wideband?
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Old Aug 31, 2005 | 12:24 AM
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the controller uses the 6066,

the built in uses the LSM11, if your ecu is a "s" model yuo cannot use a LSM11 on it

Dale
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Old Aug 31, 2005 | 12:46 AM
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gotcha
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Old Aug 31, 2005 | 09:59 AM
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Dale,

With the 6066 how far away from the turbo do you recommend installing it? I have the LTX12S and my DP is only about 3ft long it exits right behind the front tire. The car is not for street use it's a track car, no mufflers.
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Old Aug 31, 2005 | 02:41 PM
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as far as possible.
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Old Aug 31, 2005 | 05:52 PM
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Originally Posted by GUITARJUNKIE28
as far as possible.
I understand as far as possible but like I stated my whole exhaust is about 3ft long it is open exhaust. The dump pipe exits right behind my front tire will it be affected if it is to close to the opening where the exhaust gases exit?
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Old Aug 31, 2005 | 06:02 PM
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i would put it about a 6in from the end and you should be right

Dale
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Old Sep 6, 2005 | 10:32 AM
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I run my wideband about 6 inches from the end of the pipe and at idle the readings are all screwed up (bridgeport) but with the loud pedal down it reads just fine. Ive installed it farther upstream to be able to compare the results. I keep it farther back and the sensors last longer.
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Old Sep 6, 2005 | 06:17 PM
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another thing with the LSU4 is they hate leaded fuel by the look of it, my sensor was only a few months old and had done a fair bit of race gas work and it is now reading wacko! replaced it with a new one and it was perfect again,

i would reccomend 20hours tops if using leaded race fuel

dale
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