O2 Sensor
12-23-2002, 01:14 PM
#3
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Hi ric232!
Jim at Arizona Speed and Marine has some info on O2 sensors in boats. The first problem you will have is the Mercruiser FI system has no provision for O2 so the only thing you can get is info on a monitor-not controll of your mixture. An O2 sensor that will do the job in a performance application adequately is a wide band unit that is very expensive, about $600-800. They do not tolerate leaded fuel very well. The oxygen sensor only works when hot no matter which type you use and the ceramic insulator will break with the first drop of water that touches it. Properly installed, proper computer, unleaded fuel, no water in the vicinity in the exhaust and this is the ultimate set up-VERY EXPENSIVE!!
You might call Jim at Arizona Speed-he is pretty good.
Jim at Arizona Speed and Marine has some info on O2 sensors in boats. The first problem you will have is the Mercruiser FI system has no provision for O2 so the only thing you can get is info on a monitor-not controll of your mixture. An O2 sensor that will do the job in a performance application adequately is a wide band unit that is very expensive, about $600-800. They do not tolerate leaded fuel very well. The oxygen sensor only works when hot no matter which type you use and the ceramic insulator will break with the first drop of water that touches it. Properly installed, proper computer, unleaded fuel, no water in the vicinity in the exhaust and this is the ultimate set up-VERY EXPENSIVE!!
You might call Jim at Arizona Speed-he is pretty good.
12-23-2002, 01:44 PM
#4
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On top of the Thermo Shock that Blown1500 was talking about if you could get it last the Water in the Exhaust will add O2 to the exhaust and make the sensor lie to you.
If you had dry exhaust you could make a Wide band work as an Air/fuel ratio indicator. Bosch wide band ( 5 wire sensors) are a planar style and do have an integrated heater so getting them to operation temperature would not be a problem. I work here at Bosch and can forward anyone who wants info on theses sensors(Email me [email protected]). We do not make a stand alone system that would do this for you but I have heard of companies that do build them. There was a company I saw on the internet called LambdaBoy that made one. But like Blown1500 pointed out ...they are not cheap
MikeW
If you had dry exhaust you could make a Wide band work as an Air/fuel ratio indicator. Bosch wide band ( 5 wire sensors) are a planar style and do have an integrated heater so getting them to operation temperature would not be a problem. I work here at Bosch and can forward anyone who wants info on theses sensors(Email me [email protected]). We do not make a stand alone system that would do this for you but I have heard of companies that do build them. There was a company I saw on the internet called LambdaBoy that made one. But like Blown1500 pointed out ...they are not cheap
MikeW
12-23-2002, 02:50 PM
#5
I don't see how the O2 sensor would work with the stock ECM unless it has some provision for it.
I've added a wide band (5 wire) sensor to the very top of the elbow of my CMIs. I also have "S" tailpipes so that the water is introduced well down stream of the sensor. The sensor is integrated to my F.A.S.T. ECM so that I can adjust it on the fly.
NOTE: I will only leave the sensor in for tuning purposes.
You can just buy a rich/lean indicator from PFM for what it's worth.
Later,
Dave
I've added a wide band (5 wire) sensor to the very top of the elbow of my CMIs. I also have "S" tailpipes so that the water is introduced well down stream of the sensor. The sensor is integrated to my F.A.S.T. ECM so that I can adjust it on the fly.
NOTE: I will only leave the sensor in for tuning purposes.
You can just buy a rich/lean indicator from PFM for what it's worth.
Later,
Dave
12-23-2002, 03:14 PM
#6
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Mike,
A few other problems that come about besides the fact that the ECU can't recognize a wide band, ECU cannot self calibrate, sensors cannot take water, air velocity at certain speeds will give false readings, as well as misfires, if in collector, your only getting an average of 4cylinders, under some cases, sensor will not get hot enough to read in some cases (some cold starts, overly rich conditions), draws tremendous voltage from system as well as the fact that the 5 wire sensor is still not as accurate as the 6 wire UEGO sensor at the air fuel ratios that need to be run in high performance engine typically. I've seen variations of over 1 full air fuel at the 11's and 12's when compared to the Horiba units. With the tremendous duty cycle of a marine engine, if the air fuel is not dead on, then trouble could be in the future, especially if your ECU is basing it's calibration off of a 02 sensor and can richen or lean.
It's certainly possible, but more difficult than most think.
Thanks,
Dustin
A few other problems that come about besides the fact that the ECU can't recognize a wide band, ECU cannot self calibrate, sensors cannot take water, air velocity at certain speeds will give false readings, as well as misfires, if in collector, your only getting an average of 4cylinders, under some cases, sensor will not get hot enough to read in some cases (some cold starts, overly rich conditions), draws tremendous voltage from system as well as the fact that the 5 wire sensor is still not as accurate as the 6 wire UEGO sensor at the air fuel ratios that need to be run in high performance engine typically. I've seen variations of over 1 full air fuel at the 11's and 12's when compared to the Horiba units. With the tremendous duty cycle of a marine engine, if the air fuel is not dead on, then trouble could be in the future, especially if your ECU is basing it's calibration off of a 02 sensor and can richen or lean.
It's certainly possible, but more difficult than most think.
Thanks,
Dustin
12-23-2002, 03:54 PM
#7
Registered
So basically if the air density is high the A/F will be leaner then when the air density is low, like summer boating compared cooler spring and fall boating???? To me that kinda takes some of the benefit out of fuel injection? Gottahaveit posted some plug pictures and is concerned he is running to lean since he added CMI's and a Vortech flame arrestor. Is it likely he is just running leaner because of the higher densities that come with lower winter time temps? If that is the case, how does he fatten up his mixture?
12-23-2002, 05:44 PM
#8
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Originally posted by NordicHeat
I don't see how the O2 sensor would work with the stock ECM unless it has some provision for it.
I've added a wide band (5 wire) sensor to the very top of the elbow of my CMIs. I also have "S" tailpipes so that the water is introduced well down stream of the sensor. The sensor is integrated to my F.A.S.T. ECM so that I can adjust it on the fly.
NOTE: I will only leave the sensor in for tuning purposes.
You can just buy a rich/lean indicator from PFM for what it's worth.
Later,
Dave
I don't see how the O2 sensor would work with the stock ECM unless it has some provision for it.
I've added a wide band (5 wire) sensor to the very top of the elbow of my CMIs. I also have "S" tailpipes so that the water is introduced well down stream of the sensor. The sensor is integrated to my F.A.S.T. ECM so that I can adjust it on the fly.
NOTE: I will only leave the sensor in for tuning purposes.
You can just buy a rich/lean indicator from PFM for what it's worth.
Later,
Dave
12-23-2002, 06:21 PM
#9
Charter Member #40
Charter Member
I ran the FAST systems last year with Merc/Kinsler injection. FAST uses the 5 wire NTK L1H1 wide band sensor. I started off the year by letting the engines idle lower than I should have and pulled up some water...I guess. Both quit working and I had to replace them to the tune of $400 each. After that I kept rpm up over 1000 and life was good. I am running KE pipes and haave the O2 at the collector by the tail pipe flange, probably 30" away from the end where the water dumps. Supposedly a dry type tail pipe. I will say the system was much improved, from a driveability standpoint, over carbs. I also had a bung down by a couple ports for the O2. What was interesting was that cruising around 3000, the a/f ratio readout with the injection was basically within probably .3-.4 at the port. With a dominator on top it varied probably .6 to .8 cruising.
What was nice with the FAST system is that you can specifically dial in the air/fuel ratio desired at any rpm/intake mfld pressure. A world of dif compared to a carb. I am doing some blowers for next year and will probably use the systems with injection. If you do not like the way the O2 adjusts the a/f you can miniminze or eliminate the O2 and use just rpm, map, and air temp. However, the motor still needs to see a dyno upon setup just to establish the base line.
I am not familiar with other systems but FAST has been trouble free. There are nicer systems out there, but I think the prices aare a little bit up there. For what it's worth!
What was nice with the FAST system is that you can specifically dial in the air/fuel ratio desired at any rpm/intake mfld pressure. A world of dif compared to a carb. I am doing some blowers for next year and will probably use the systems with injection. If you do not like the way the O2 adjusts the a/f you can miniminze or eliminate the O2 and use just rpm, map, and air temp. However, the motor still needs to see a dyno upon setup just to establish the base line.
I am not familiar with other systems but FAST has been trouble free. There are nicer systems out there, but I think the prices aare a little bit up there. For what it's worth!
12-23-2002, 07:26 PM
#10
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Dustin
I never heard of a 6 wire sensor. A Bosch Wide (broad) band is 5 wire (2 for the heater circuit one is ground and 2 signal wires). We don't make one. All I was stating is it would be neat to use the wide band in a stand alone system only. It would be nice to use it as feed back to control but that would require an ECU that could read a Wide band. Bosch wide bands would work very well with a Hi Po systems. They can read richer and leaner Air/ fuel ratios than a tube type or planar sensor. As I agree with you water will give you a false reading but air velocity (I am assuming you mean Exhaust velocity because intake velocity will have no effect at all on a O2 sensor) will not affect a Bosch Wide band. As a wide band works under the same principle (Nernst principle) the ECU reads Pump cell current rather than voltage and this sensor gives an unmistakable, continuous signal.
MikeW
I never heard of a 6 wire sensor. A Bosch Wide (broad) band is 5 wire (2 for the heater circuit one is ground and 2 signal wires). We don't make one. All I was stating is it would be neat to use the wide band in a stand alone system only. It would be nice to use it as feed back to control but that would require an ECU that could read a Wide band. Bosch wide bands would work very well with a Hi Po systems. They can read richer and leaner Air/ fuel ratios than a tube type or planar sensor. As I agree with you water will give you a false reading but air velocity (I am assuming you mean Exhaust velocity because intake velocity will have no effect at all on a O2 sensor) will not affect a Bosch Wide band. As a wide band works under the same principle (Nernst principle) the ECU reads Pump cell current rather than voltage and this sensor gives an unmistakable, continuous signal.
MikeW
