Blow through MAF system
07-13-2007, 10:00 AM
#64
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Originally Posted by gt37vgt
MAF versus MAP
maf measures the air that goes into your engine and map extrapolates the air that goes into your engine .Its not the the maf making power its just the ideal tune that makes power that is a bit easier to achieve with a maf set up .
yeh as stated above the motronic provides fuel according to maf any map set up used with montronic has to then be used to drive a maf emulator added complexity that you don't want .
another thing that makes this blow through setup more accurate is that the closer to the engine you are measuring closer you are in real time. A draw through MAF measures the air the engine will use in a moment from now that moment is a complicated varying equation . that moment is almost gone in this blow through set up .
I cam prove this mathematically if you wish .
dang if i had more time i would be Tims australian agent .
maf measures the air that goes into your engine and map extrapolates the air that goes into your engine .Its not the the maf making power its just the ideal tune that makes power that is a bit easier to achieve with a maf set up .
yeh as stated above the motronic provides fuel according to maf any map set up used with montronic has to then be used to drive a maf emulator added complexity that you don't want .
another thing that makes this blow through setup more accurate is that the closer to the engine you are measuring closer you are in real time. A draw through MAF measures the air the engine will use in a moment from now that moment is a complicated varying equation . that moment is almost gone in this blow through set up .
I cam prove this mathematically if you wish .
dang if i had more time i would be Tims australian agent .
07-13-2007, 10:18 AM
#65
Originally Posted by sawood12
Is this right? I thought MAP accurately and directly calcuates the air mass via inputs from a pressure and temp sensor in the manifold and knowing the volume of the manifold you can calculate the actual mass of air in the manifold. MAF measures the airflow and temp and calculates it that way. The MAP is a direct measurement (i.e. no extrapolations or assumptions requred) whereas the MAF requres you to use assumptions about how the air flows through the sensor i.e. in theory MAP is the ultimate.
I think the rest of his commects are really comparing two types of MAF setups... blow through and draw through.
07-13-2007, 02:22 PM
#66
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Originally Posted by Mark-87-951
What's the advantage of using a blow-off valve? Or is that simply because a recirc valve isnt appropriate for this set up?
Recirc stays open at idle. Blow-off valve stays closed. If you use a recirc,it will pull in fresh unfiltered air and can cause irratic idle.
07-13-2007, 02:27 PM
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Originally Posted by sawood12
Is this right? I thought MAP accurately and directly calcuates the air mass via inputs from a pressure and temp sensor in the manifold and knowing the volume of the manifold you can calculate the actual mass of air in the manifold. MAF measures the airflow and temp and calculates it that way. The MAP is a direct measurement (i.e. no extrapolations or assumptions requred) whereas the MAF requres you to use assumptions about how the air flows through the sensor i.e. in theory MAP is the ultimate.
Manifold Absolute Pressure(MAP) does not know volume.Only pressure.It is sort of like an on and off switch.You have no voltage,then you have alot of voltage instantly whereas MAF has a nice linear voltage. Nothing abrupt.It senses the actual mass-flow of the incoming air.
MAPs work well but typically you combine the signal with a tps for example and use a blending of both of those signals so you have a car that is smooth running and idling.
They both have their advantages and disadvantages
07-13-2007, 04:52 PM
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Originally Posted by 87951
That is one of the better explanations of the MAF vs MAP differences I've read here.
Because I have skills that ya'll dont kow about
07-13-2007, 05:15 PM
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I'm dying For John to write a program for this. He'll never have to ask you again, "what type of Turbo and mods to you have?" Just injector size, Fuel type, RPM, ETC. He shouldn't have much trouble?..... If I buy one John and send it to you? Could you do it?
07-13-2007, 06:32 PM
#71
Drifting
I'm having Tim install this on my 3.0 project. Tim is in charge of all tuning, turbo sizing, intake, exhaust, headers, and whatever else necessary to make this project one of the best he has done on a 951. I'll let you know how well everything works and post dyno runs. The car should be done in September.
George
George
07-13-2007, 10:14 PM
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MAF : Mass Air Flow a fixed voltage is sent through the nicrome wire element then thew temprature is measured at he end of the wire . then there is a little op amp and thermicouple so the wire temp is inversly proportianal to to voltage out .
there for colder air will send more voltage out of the MAF/afm this is how MAF eliminates the need for air temp sensor. some put a little trim pot inplace of the temp sensor and some put a resistor . If you burn your chips with heaps of air temp ignightion trim you can use this as an external ihnightion trim set up
there for colder air will send more voltage out of the MAF/afm this is how MAF eliminates the need for air temp sensor. some put a little trim pot inplace of the temp sensor and some put a resistor . If you burn your chips with heaps of air temp ignightion trim you can use this as an external ihnightion trim set up
07-14-2007, 12:11 AM
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Originally Posted by TurboTim
Recirc stays open at idle. Blow-off valve stays closed. If you use a recirc,it will pull in fresh unfiltered air and can cause irratic idle.