Lexus AFM or GM Air meter
- Thread starter Crazybobmundo
- Start date
Readings can stray from the target values as a result of contamination of the wire and for the sake of accuracy, an additional input from an integrated intake temperature sensor is sometimes used. Many hot wire MAFs incorporate a burn off cycle when the ignition is switched off, heating the element to over 1800-degrees F to clear it of contamination. Hot wire sensors are the most physically delicate and easily contaminated of all the air flow and mass sensors.
Especially in a blow through setup with oil in the intercooler pipes, have fun getting it to idle...
Especially in a blow through setup with oil in the intercooler pipes, have fun getting it to idle...
Reasons not to use a post-intake MAF:
1) BOVs produce finite pressure waves in the IC piping that travel backwards and then forwards across the MAF several times. The wire does not sense directionality, so the pressure release wave looks just like extra air going down the tube into the engine to the sensor. End product is that it will still incorrectly fuel the motor on blow off.
2) The wire will not tolerate oil in the pipes present after the PCV tube. It will gum up and cause the air flow readings will drift over time. Additional expense will have to be incurred to keep the system oil free.
3) Experimentation with the MAF is required to ensure that its internal heat compensation circuitry can handle the temperatures that may be present in the system. Even if it is mounted post IC, temperatures of well over 200F can be present during heat soak.
4) A MAF located anywhere except where stock systems have them will immediately fail CA visual tests.
5) MAFs capable of measuring air flow in the ranges required are at least 3" in diameter. Very few people have 3" IC pipes and TBs, so additional expensive transition couplers and the flow penalty of going through yet another reduction coupling is incurred.
1) BOVs produce finite pressure waves in the IC piping that travel backwards and then forwards across the MAF several times. The wire does not sense directionality, so the pressure release wave looks just like extra air going down the tube into the engine to the sensor. End product is that it will still incorrectly fuel the motor on blow off.
2) The wire will not tolerate oil in the pipes present after the PCV tube. It will gum up and cause the air flow readings will drift over time. Additional expense will have to be incurred to keep the system oil free.
3) Experimentation with the MAF is required to ensure that its internal heat compensation circuitry can handle the temperatures that may be present in the system. Even if it is mounted post IC, temperatures of well over 200F can be present during heat soak.
4) A MAF located anywhere except where stock systems have them will immediately fail CA visual tests.
5) MAFs capable of measuring air flow in the ranges required are at least 3" in diameter. Very few people have 3" IC pipes and TBs, so additional expensive transition couplers and the flow penalty of going through yet another reduction coupling is incurred.
I see.
But what about catch cans, are they not effecient enough to keep oil away from the pipes?
But what about catch cans, are they not effecient enough to keep oil away from the pipes?
hook a catch can into the stock pcv system before the turbo. Personally id put the MAF where the stock AFM is so the catch can/pcv is behind it.