K&N Filter WARNING for EFI bikes?
Jun 17, 2005 | 07:09 PM
#21
Range Rover
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K&N Filter WARNING for EFI bikes?
I seriously doubt the air temp sensor will be effected by oil. The problem with MAFs is that the sensor wire gets very hot. Air drawn through the sensor cools down the wire, which, in effect, is how it determines the amount of airflow. Oil that comes in contact with the sensor wire gets cooked onto the wire and ultimately gives a false reading of airflow. It's not a problem in automotive applications if you periodically clean the sensor with carb cleaner. I would suspect that the warning has more to do with leaner mixtures.
Jun 17, 2005 | 07:27 PM
#22
Extreme Pro Rider
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From: Lake Havasu City, AZ
K&N Filter WARNING for EFI bikes?
Originally posted by: 67bullet
I need some more details because I thought you said the computer doesn't make any fuel adjustments.
I have the power commander on my bike and everything is related to throttle open percentage. A given amount of fuel to a given amount of throttle position, given by the TPS sensor.
I need some more details because I thought you said the computer doesn't make any fuel adjustments.
I have the power commander on my bike and everything is related to throttle open percentage. A given amount of fuel to a given amount of throttle position, given by the TPS sensor.
Jun 17, 2005 | 09:34 PM
#23
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K&N Filter WARNING for EFI bikes?
Back in my mustang days this was a big debate also with the temp sensor. I have even read an article that a mustang magazine did with free HP tips. This was a myth. They pulled the temp sensor and put it in a cup of ice and made a dyno run. It did nothing to richen the fuel mixture. They also did it with warm water. again nothing. They concluded that it was a sensor used on inital startup to help the fuel table when the motor was being started and needed to be electronicaly choked. They claimed it was probably disabled after the motor warmed up.
Myself I have a K&N on my EFI with no problems what so ever. My brother has one on his 700 EFI now for almost a year. Again No problems.
Myself I have a K&N on my EFI with no problems what so ever. My brother has one on his 700 EFI now for almost a year. Again No problems.
Jun 17, 2005 | 09:52 PM
#24
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K&N Filter WARNING for EFI bikes?
Originally posted by: jefffoxsr
Bullet,
What happens is that if oil gets on the air temp sensor then it's possible for that sensor to give a reading to the computer that the intake air temp is much lower than it really is.
This false low temp reading can happen because the oil on the sensor can conduct heat similar to water, thus giving a false low intake air reading.
This is similar to the human body sweating to cool itself down. When the sweat conducts your body heat to the ambient air around you, then you become cooler.
So you can imagine a wet sensor, that remains wet with oil, and then a ton of intake air blows over the sensor to dissipate the heat off the sensor thereby cooling it off.
Then the computer trims the fuel based on this and then the air fuel ratio is too lean. If the air/fuel ratio is over lean then we all know what can happen.
If anyone needs more details on this let me know.
If you don't over oil the filter then I see no problem.
Bullet,
What happens is that if oil gets on the air temp sensor then it's possible for that sensor to give a reading to the computer that the intake air temp is much lower than it really is.
This false low temp reading can happen because the oil on the sensor can conduct heat similar to water, thus giving a false low intake air reading.
This is similar to the human body sweating to cool itself down. When the sweat conducts your body heat to the ambient air around you, then you become cooler.
So you can imagine a wet sensor, that remains wet with oil, and then a ton of intake air blows over the sensor to dissipate the heat off the sensor thereby cooling it off.
Then the computer trims the fuel based on this and then the air fuel ratio is too lean. If the air/fuel ratio is over lean then we all know what can happen.
If anyone needs more details on this let me know.
If you don't over oil the filter then I see no problem.
Colder air requires more fuel. This would cause a rich condition.
Oh, and check out pic #5 on my page. I still have a clean intake track.
Jun 17, 2005 | 09:57 PM
#25
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K&N Filter WARNING for EFI bikes?
bullet, the computer definitely makes fuel adjustments. The computer won't make adjustments based on added air flow from an aftermarket air filter because Polaris doesn't use a mafs or an O2 sensor. Sorry for the confusion.
EAB, I typed my post too fast, yes more fuel for cooler temps. I'll go back and fix the post. Thanks.
EAB, I typed my post too fast, yes more fuel for cooler temps. I'll go back and fix the post. Thanks.
Jun 17, 2005 | 10:01 PM
#26
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K&N Filter WARNING for EFI bikes?
I have no idea in what way Polaris uses the air temp sensor. It may just be for warm up. It would be nice to know exactly how it's used.
In any event keeping it clean will be necessary to avoid having the engine run incorrectly.
If the K&n is prepared properly then there probably won't be a problem.
In any event keeping it clean will be necessary to avoid having the engine run incorrectly.
If the K&n is prepared properly then there probably won't be a problem.
Jun 17, 2005 | 11:43 PM
#27
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Range Rover
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K&N Filter WARNING for EFI bikes?
Thanks Budman...I had enough Nitrous on the Camaro to clean out any sensor that were on it. The pic was before the Fogger kit was installed..
Still not real sure what the air temp sensor is for. I used to have a 87 Mustang with the speed density factory Ford system and after many modifacations switched to mass air and a programable chip.. It was alot more fun to mess with then Polaris's EFI system....
Oleman I agree with ya...the ole Mustangs ran the same with the sensor hot and cold.
Still not real sure what the air temp sensor is for. I used to have a 87 Mustang with the speed density factory Ford system and after many modifacations switched to mass air and a programable chip.. It was alot more fun to mess with then Polaris's EFI system....
Oleman I agree with ya...the ole Mustangs ran the same with the sensor hot and cold.
Jun 18, 2005 | 11:48 AM
#28
Range Rover
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K&N Filter WARNING for EFI bikes?
Ford uses the air temp sensor for timing adjustments. They use it to pull timing out of the motor at rather high temperatures. Coolant temps are used for fuel adjustments. I believe this is a common programming strategy.
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