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Wideband O2 sensor bung placement


trwebb26

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Now that everybody has their Innovative Wideband O2 sensor from Summit (for those that were lucky like me) - I'm curious where everybody has their sensor placed. I know that it has to be before the cat... but my car doesn't have a cat (did any Z?). The innovative website movies (http://www.innovatemotorsports.com/resources/lm101.php) say to put the sensor as far downstream as possible to avoid heat... not like this:

 

O2.JPG

 

 

but at least 2-3 feet from "the end of the tailpipe" so the thing doesn't read false lean at low idle. I was going to shoot for someplace before the rear suspension, but I haven't gotten underneath the car to look around, yet. As always - pictures are king.

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If you have a infrered thermometer that would be ideal. i believe innovate suggests a 900degree surface temperature. i ended up placing mine about a foot away from the turbo.

 

I have run a lm1 a good bit today and I havent recieved any error messages and everything seems to be kosher.

 

Picture:

3_inch_downpipe_008_Medium.sized.jpg

 

I redid my downpipe to move them farther away, dont want to risk damage to the sensor.

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Does anybody know what the temperature of a downpipe 10" from a turbo is? I personally have seen them glow red - probably greater than the reccomended 900 degrees F for some applications. That copper heatsink isn't going to help your EGT's over 1300 degrees, either. I'm not sure what a usual heat disipation from a turbo outlet is... It is possible that (for instance) - every inch you get away from the turbo, the downpipe temp reduces by 100 degrees F (dependant on diameter/area of the pipe, wall thickness, material, etc). I don't know that, just giving an example. 240hoke is right - it would be helpful for somebody with an infared temp guage to check it out.

 

I just want to know where people are putting their sensor - not get into an argument about the details and justification why somebody put the sensor where they did.

 

Maybe the question should be - where is the ideal place for the sensor? All the information I can find says to put it as far away from the heat as possible - but not so far downstream that free air can rush in the tailpipe and give lean readings. Comments?

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From everything I have researched I put the wideband about 3 feet downstream from the turbo. It is not a concern to be farther away unless you have exhaust leaks or you need ultra fast wideband updates (which the $35 bosch sensor has been argued to be slower at responding than the $120 bosch sensor anyway). I don't believe in the response time argument for street applications. just my 2 cents

 

Of course position the sensor so exhaust condensation won't puddle up on it (put it on top of the pipe, or top portion)

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If you put it on one of the runners - you will only be getting the air-fuel raitio for that cylinder. If you put it in the collector - it would average out all of the cylinders and give you a more general reading for how the engine is performing.

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What about NA cars? Does anyone know if it would be safe to mount it in the existing bung on my MSA 3-2 headers? Or should I put a new bung down on the collector?

 

Depends on what type of O2 you have. You want it close enough that it will heat up quickly, unless you have a heated type sensor.

 

To get a more accurate reading, I would put it the collector just after all the pipes come together.

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Now that everybody has their Innovative Wideband O2 sensor from Summit (for those that were lucky like me) - I'm curious where everybody has their sensor placed. I know that it has to be before the cat... but my car doesn't have a cat (did any Z?). The innovative website movies (http://www.innovatemotorsports.com/resources/lm101.php) say to put the sensor as far downstream as possible to avoid heat... not like this:

 

O2.JPG

 

 

but at least 2-3 feet from "the end of the tailpipe" so the thing doesn't read false lean at low idle. I was going to shoot for someplace before the rear suspension' date=' but I haven't gotten underneath the car to look around, yet. As always - pictures are king.[/quote']

forgive me if this is a stupid question but are there are two sensors in that pipe. One for the air/ fuel ratio guage and one for the megasquirt? is that right? is it possible to use the same sensor for both a air/ fuel ratio guage and for mega squirt?

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forgive me if this is a stupid question but are there are two sensors in that pipe. One for the air/ fuel ratio guage and one for the megasquirt? is that right? is it possible to use the same sensor for both a air/ fuel ratio guage and for mega squirt?

 

 

The LC-1 has 2 analog outputs that can be programmed as the input to the ECU (SDS for me, MS for someone else).

 

When I originally built the downpipe I put 2 bungs in, one for a NBO2 for the ecu and the other for a wideband when I put it on the dyno. Now I'm using one for the wideband sensor on the car, and keeping the other one plugged unless I go to the dyno.

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Depends on what type of O2 you have. You want it close enough that it will heat up quickly, unless you have a heated type sensor.

 

Just to make sure we are all on the same page, all wideband O2 sensors have there own heater run by the wideband controller. They do not need any heat from the exhaust to work. It is important that they are not close enough to the engine to see more than 900 degrees because that overheats the sensor and the reading will not be accurate. When in doubt use the heatsink from innovate.

 

Some narrowband sensors do not have a heater and must be close to the engine to use the exhaust heat.

 

A single LC-1 wideband setup is capable of running the megasquirt and an AFR gauge because it has 2 outputs as mentioned.

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Just so that I have understood this correctly.

 

If I wanted to use the Innovate LM1 and keep the existing bung in my MSA down pipe (see pic for position of bung below) I could do so "safely", without having to reposition the bung, as long as I use the heatsink from Innovate. RIGHT?

 

114797376.jpg

 

Thanks.

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Guys I jsut wanted to add a little bit of my expirence here from the last week. In the Inovate manual if im not mistaken they prefer it to be as far away as possible without the risk of excess air coming in for the tail pipe. The reason for running it so close to the motor on most cars is the fact that most cars have cats.

 

I called innovate tech support when I was trying to figure out why my o2 readings were choppy. The tech suggested that I try moving the o2 farther away then I had it. He said on his supra for best results they moved it 3' away. The manual suggests 2-3 feet from the rear of the car if it doesnt have cats if im not mistken, ill double check when i get home.

 

I ended up remounting mine in the rear of the car at the front of the differential. It did seem to give me more stable o2 reading. I like the location better so there it will stay.

 

I will say that I recived no error messages running it where it was in the first picture I posted so it should have been okay.

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And 240z thats a nice DP you got there. I think its more then likely is too clsoe for the wideband sensor though. I would suggest not worrying about cutting up that nice piece.

 

You can get a new bung and plug from any exhaust shop, my local shop sells good bungs for 4 bucks and nice allen type plugs for 3. I suggest welding the bung into your exhaust system downstram and plugging up your pipe. Just my 2 cents.

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