how to get accurate afr readings?
#1
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how to get accurate afr readings?
i'm wanting to get some accurate afr readings on my car that has headers... i've done a few searches and some are saying that it depends on each motor on where the best place to get the readings from.
either a sniffer type from the exhaust tips, or drilling a hole in the collector, exhaust, header, etc.
the first attempt at getting some afr readings from my car failed by the sniffer... i'm not sure if this was a problem with my car or the sniffer
if drilling a hole somewhere is the best way to go, then where should it be drilled and what parts are necessary?
does it matter whether i have cats or not?
either a sniffer type from the exhaust tips, or drilling a hole in the collector, exhaust, header, etc.
the first attempt at getting some afr readings from my car failed by the sniffer... i'm not sure if this was a problem with my car or the sniffer
if drilling a hole somewhere is the best way to go, then where should it be drilled and what parts are necessary?
does it matter whether i have cats or not?
Last edited by bluejae; 07-16-2011 at 12:11 PM.
#2
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
I have a Innovate LC1 in my truck after the rear mount turbo and it works great. The truck has a SD tune and no cats. Basically it is over the rear axle. So if you have no cats then you can put it further back in the exhaust. If you have cats it should be in front of the cats but may be subject to higher temps and turbulence which can both affect accuracy and life of the sensor. The sensor should be mounted above the center line of the pipe and closer to 12:00 o'clock is best. Drill or blow a hole in the pipe with a torch and weld in a bung. Very easy to do at an exhaust or performance shop. The bungs come with a screw in insert if you want to remove the sensor and plug the bung up after you get some readings.
The LC1 is for permanent installation and the LM1 is for temporary installation and should work from any 12v power outlet in the car. The LM1 does logging as well from internal memory so that you can upload the data to a laptop for viewing.
The LC1 is for permanent installation and the LM1 is for temporary installation and should work from any 12v power outlet in the car. The LM1 does logging as well from internal memory so that you can upload the data to a laptop for viewing.
#3
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i'm just looking for the best option to get some afr readings without spending too much... i want to put it on a dyno and get the afr readings... and after that, i won't need it again
is it possible to get afr readings from this car with an exhaust probe?
is it possible to get afr readings from this car with an exhaust probe?
#4
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
Any decent dyno shop should be able to get you WOT AFR readings from an exhaust probe. Non WOT readings will not be very accurate unless you have no cats and will read a very consistent 14.7:1 (stoichiometric) when not in the PE tables at WOT.
#6
The sniffer should work... maybe it was just a bad day.
You could borrow someone's wideband a/f guage, and screw the sensor in where your existing o2 sensors are (providing you have a tune that negates those sensors anyways). However, don't go drilling holes in your beautiful headers, just because a shop's sniffer isn't working properly.
You could borrow someone's wideband a/f guage, and screw the sensor in where your existing o2 sensors are (providing you have a tune that negates those sensors anyways). However, don't go drilling holes in your beautiful headers, just because a shop's sniffer isn't working properly.
#7
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The sniffer should work... maybe it was just a bad day.
You could borrow someone's wideband a/f guage, and screw the sensor in where your existing o2 sensors are (providing you have a tune that negates those sensors anyways). However, don't go drilling holes in your beautiful headers, just because a shop's sniffer isn't working properly.
You could borrow someone's wideband a/f guage, and screw the sensor in where your existing o2 sensors are (providing you have a tune that negates those sensors anyways). However, don't go drilling holes in your beautiful headers, just because a shop's sniffer isn't working properly.
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#10
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2008 A8L, 2002 996TT X50, 2009 X5
#11
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I was at 12.7 when I dynoed.
Last edited by _AMG_; 07-20-2011 at 05:04 AM.
#13
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I have a Innovate LC1 in my truck after the rear mount turbo and it works great. The truck has a SD tune and no cats. Basically it is over the rear axle. So if you have no cats then you can put it further back in the exhaust. If you have cats it should be in front of the cats but may be subject to higher temps and turbulence which can both affect accuracy and life of the sensor. The sensor should be mounted above the center line of the pipe and closer to 12:00 o'clock is best. Drill or blow a hole in the pipe with a torch and weld in a bung. Very easy to do at an exhaust or performance shop. The bungs come with a screw in insert if you want to remove the sensor and plug the bung up after you get some readings.
The LC1 is for permanent installation and the LM1 is for temporary installation and should work from any 12v power outlet in the car. The LM1 does logging as well from internal memory so that you can upload the data to a laptop for viewing.
The LC1 is for permanent installation and the LM1 is for temporary installation and should work from any 12v power outlet in the car. The LM1 does logging as well from internal memory so that you can upload the data to a laptop for viewing.
#14
Just pick up a simple digital wide band monitor with 02 bung. Unplug one of your secondary O2 sensors then screw in the monitor and drive around.
This will only monitor one bank of the engine at a time...
Sniffers aren't as accurate and drilling is unnecessary.
This will only monitor one bank of the engine at a time...
Sniffers aren't as accurate and drilling is unnecessary.
#15
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
The LC1 is hardwired in but it can be moved and rewired into another vehicle. The LM1 is very portable and easily moved. The LM1 works with power from most 12v outlets in the car including the lighter socket. The hardest part is finding /making access for the sensor wire into the interior of the car. It also has built in logging functions for AFR. You can use an O2 bung on your car but will get a code eventually or you can weld in a separate bung if you want to use the sensor more extensively.
#16
I've been told that a reasonable rule of thumb is to add 0.5 to the AFR reading on the dyno to approximate an on the road AFR. Or that a much too simplistic approach?
#17
http://tunertools.com/proddetail.asp?prod=SNP-AF-5000
All you need is something like that. Cruise should be around 14-14.5 and WOT 12.5-13.0.
I just recently tested my AFR out this way. Drove around all day with it.. Don't really need to monitor more then once to insure its correct.
All you need is something like that. Cruise should be around 14-14.5 and WOT 12.5-13.0.
I just recently tested my AFR out this way. Drove around all day with it.. Don't really need to monitor more then once to insure its correct.
#18
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AFR should be present at the OBD2 port. There are several electronic read outs that you can plug and play to get everything that comes from the OBD2 port
#20
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but since the lc1 is a permanent install, i don't think we can share it... but i'm not sure...
i believe all these are compatible with the ot2 i have... and you're welcome to borrow it.
Compatible with all Innovate MTS (Modular Tuning System) devices, including LC-1 “Lambda Cable” Air/Fuel Ratio sensor controller, LM-2 Air/Fuel Ratio meter with analog inputs, TC-4 4-channel thermocouple interface, and more.
#22
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from what i know.. the ot2 connects to the obd port and the lc1 once installed, it can then be connected to the ot2... then all the info can be seen through wifi on idevices or a computer with the software installed
Last edited by bluejae; 03-07-2012 at 05:04 PM.