which wide band o2 sensor
#19
Instructor
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I installed the Innovate LC-1 and XD-16 gauge last weekend after seeing how well it worked on a friend’s 1991 Turbo. I have an older set of B&B headers and used the O2 bung just before the turbo. This is temporary until I find the time to add the bung provided to the muffler just after the turbo.
I've heard from several folks that the sensor should be located after the turbo? Who has a good explanation for that?
Lyall
I've heard from several folks that the sensor should be located after the turbo? Who has a good explanation for that?
Lyall
#21
Nordschleife Master
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The O2 sensors are sensitive to pressure and temperature. Installing the sensor before the turbo exposes it to backpressure and it will have an incorrect reading. Installing it after the turbo solves the pressure issue.
#22
Instructor
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The pressure and temperature problems I've heard before, breaking apart and passing through the turbo is a new one.
I plan to place the bung after the turbo just before the muffler.
How far off can the AFR readings be for these two locations?
Lyall
I plan to place the bung after the turbo just before the muffler.
How far off can the AFR readings be for these two locations?
Lyall
#23
Rennlist Member
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Out of curiousity what do you guys set the o2 mix to at idle?
Can anyone give me some rough trend numbers from their widebands on where your AFR should be from idle, steady throttle, up to peak boost and then off the gas? Just interested in rough trends so that I can benchmark what I am seeing.
Can anyone give me some rough trend numbers from their widebands on where your AFR should be from idle, steady throttle, up to peak boost and then off the gas? Just interested in rough trends so that I can benchmark what I am seeing.
#24
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Still looking for an answer to the before vs after the turbo...regarding temperature (ie...what type of reading delta to expect). The LC-1 will tell you if the exhaust is too hot. Here's a discussion on the topic off the IM forum;
http://www.innovatemotorsports.com/f...light=location
http://www.innovatemotorsports.com/f...light=location
#25
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More info for those interested...got this from the Innovative forum;
On most turbo applications the headers and path to the turbo is very short and retains a lot of heat. That heat is typically too high for a wideband. On a 930 the raw exhaust usually goes through the heater boxes and follows a fairly long path which cools it significantly. That's why you don't see any overheat errors. The second problem pre-turbo is the high pressure. Widebands read richer than actual in rich gas and leaner than actual in lean gas. Although the LC-1/LM-1 are much less affected by that than conventional widebands, the effect is still there.
The 930 engine, different than most aftermarket turbo conversions, is specifically designed for turbo operation. It runs more efficiently under boost than most. This means also it's EGTs pre-turbo are lower because the engine extracts more mechanical energy from the burned gas and pushes less energy in form of heat out the exhaust.
Regards,
Klaus
On most turbo applications the headers and path to the turbo is very short and retains a lot of heat. That heat is typically too high for a wideband. On a 930 the raw exhaust usually goes through the heater boxes and follows a fairly long path which cools it significantly. That's why you don't see any overheat errors. The second problem pre-turbo is the high pressure. Widebands read richer than actual in rich gas and leaner than actual in lean gas. Although the LC-1/LM-1 are much less affected by that than conventional widebands, the effect is still there.
The 930 engine, different than most aftermarket turbo conversions, is specifically designed for turbo operation. It runs more efficiently under boost than most. This means also it's EGTs pre-turbo are lower because the engine extracts more mechanical energy from the burned gas and pushes less energy in form of heat out the exhaust.
Regards,
Klaus
#26
Nordschleife Master
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With the MoTeC ECUs you can provide a pressure and temperature compensation calibration so the sensor reads correctly, however, you'd have to spend the time to generate those compensataions. It is better to just install the sensor post turbo.
#28
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I have just had a WMS Wideband O2 device installed in my car.
First my question: Where does one connect the orange wire for the tach signal? Connecting it to the negative of the ignition coil makes the display go blank.
I chose this product for the following reasons:
1. With a little help, it fits in the spot of my choice
2. the price advantage over Motec PLM (that would also fit in the same slot) is significant
3. This device shows me everything I am capable of comprehending at this time as a 3 month old Porsche 930 owner
As for pictures, I tried taking a few but either my camera is bad or I don't know how to set up the lighting exposure properly yet. Most likely the camera is bad.
Here's two pictures, from one you can just barely see where it is located and in the second picture one can tell that it actually shows numbers. In real life the numbers are actually easy to see.
First my question: Where does one connect the orange wire for the tach signal? Connecting it to the negative of the ignition coil makes the display go blank.
I chose this product for the following reasons:
1. With a little help, it fits in the spot of my choice
2. the price advantage over Motec PLM (that would also fit in the same slot) is significant
3. This device shows me everything I am capable of comprehending at this time as a 3 month old Porsche 930 owner
As for pictures, I tried taking a few but either my camera is bad or I don't know how to set up the lighting exposure properly yet. Most likely the camera is bad.
Here's two pictures, from one you can just barely see where it is located and in the second picture one can tell that it actually shows numbers. In real life the numbers are actually easy to see.
Last edited by Olli; 06-17-2006 at 05:05 PM.