Sedan Chat Thread
Originally Posted by slartibartfast
Mass air flow sensor does not sense air velocity. It measures the amount of voltage necessary to maintain a given temperature of the hot wire, which is determined by, well, mass flow past the wire. Speed/density systems like those fitted in Hondas use velocity and manifold absolute pressure (MAP) as the primary measuring device. While the G does calculate MAP, it's used as a tweak to what's sensed by the hot wire.
The larger MAF does require new/modified ECU fuel maps so the computer can determine the proper fuel requirement for the new voltage range. Air velocity doesn't figure in for the G air flow sensor. It's common on turboed SR20s to use Mustang Cobra MAFs since they can measure larger masses of air than the stockers. They both use the same voltage range (1-5V?) but the MAF diameter determines what 1V represents in air mass flowing past the hot wire.
The larger MAF does require new/modified ECU fuel maps so the computer can determine the proper fuel requirement for the new voltage range. Air velocity doesn't figure in for the G air flow sensor. It's common on turboed SR20s to use Mustang Cobra MAFs since they can measure larger masses of air than the stockers. They both use the same voltage range (1-5V?) but the MAF diameter determines what 1V represents in air mass flowing past the hot wire.
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From: Columbia S.C.
Just thought i'd post this up if anyone is interested. I've read sometimes when posters are looking or asking about Y pipes. This may have already been posted in another thread so apologizes if i'm late to the party 
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ISR Performance Exhaust Y-Pipe - Nissan 370z / G37 - Enjuku Racing Parts, LLC
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The ISR Performance 370z / G37 Y-pipe utilizes 2.75" stainless steel piping along with bellowed flex sections running from the 2 bolt catalytic converter flanges back to the high performance velocity merge. The Y pipe then steps to 3" stainless piping coming out of the velocity merge to the rear 3" exhaust flange. The Y pipe also features an integrated dimpled gusset plate tying the two individual runners together for increased strength and rigidity.
ISR Performance Exhaust Y-Pipe - Nissan 370z / G37 - Enjuku Racing Parts, LLC
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The insert restores the pipe diameter at the MAF back to stock.
Without the insert, a calibration (aka "tune") will be required where the MAF function table (MAF voltage vs airflow) will be updated for the new intake.
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Joined: Dec 2015
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Wow, it has a 3" outlet. Don't most x-pipes have 2 1/4 - 2 1/2?
Originally Posted by SonicVQ
Our hot-wire MAFs sample a small portion of the air flow and calculates the total airflow. If the MAF pipe is larger at the MAF it will under report the actual air flow, and you will run much leaner, like the 15.5:1 mentioned earlier.
The insert restores the pipe diameter at the MAF back to stock.
Without the insert, a calibration (aka "tune") will be required where the MAF function table (MAF voltage vs airflow) will be updated for the new intake.
The insert restores the pipe diameter at the MAF back to stock.
Without the insert, a calibration (aka "tune") will be required where the MAF function table (MAF voltage vs airflow) will be updated for the new intake.
Or, it's just calibrated to that size piping from factory? They set parameters based on what they see with the oem size piping? You guys are explaining what the maf does. But I'm trying explain what the larger diameter piping does to throw off the MAF.. That's where AEM was talking about slower air moving through the piping at that point and tricking the MAF. Because if the airflow didn't change the MAF would still be correct... Right? This may just be a lost cause.
lolHere's a pic to stay on topic. Front end Friday, post em up. Edit: I though i was in the show off your sedan thread
"The larger 76mm unit, when equipped with a conical filter directly on the end of the unit (which leans out the MAF signal by reducing air velocity) needed the “richer†Black calibration tube which increases air velocity across the sensor in order to achieve the same calibration as the other 2 units"
That's where I was saying The larger diameter in piping affects velocity/speed which in return throws off the voltage of the MAF because it will not cool the same. It's measurement is not independent of the airs velocity/speed. Does the MAF measure velocity or speed? No. Does the velocity affect the hot wire setup. Yes. So in the end the larger piping will change the velocity of airflow and lean out the MAF reading. This is because the air is moving slower through the pipe causing a higher wire temperature. The higher temp makes the MAF sensor under estimate the airflow. There's a lot of good reads on this. Every article or experiment lists the same affects. Larger diameter ==> Lower velocity ==> Hotter temp ==> Leaner conditions.
That's where I was saying The larger diameter in piping affects velocity/speed which in return throws off the voltage of the MAF because it will not cool the same. It's measurement is not independent of the airs velocity/speed. Does the MAF measure velocity or speed? No. Does the velocity affect the hot wire setup. Yes. So in the end the larger piping will change the velocity of airflow and lean out the MAF reading. This is because the air is moving slower through the pipe causing a higher wire temperature. The higher temp makes the MAF sensor under estimate the airflow. There's a lot of good reads on this. Every article or experiment lists the same affects. Larger diameter ==> Lower velocity ==> Hotter temp ==> Leaner conditions.
Last edited by Gregor12; May 6, 2016 at 04:02 PM.
Originally Posted by slartibartfast
http://www.cnlperformance.com/MAF_info.php?section=15
