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|Pull through setup know exactly how much air the engine is consuming.|
I vote PULL THROUGH ..
MAF BEFORE turbo ... better all around Driveability, and no erroneous readings like on the blow through setups.
Pull through setup know exactly how much air the engine is consuming.
|BOV goes at least 6" in front of MAF|
Blow Through Cons Disputed.
- If not Properly Placed on the Intake Side can cause Hesitation in Motor.
Your car is almost gauranteed to hesitate if you place the MAF in a pull through configuration.
Doing it as show in the picture (before the turbo) isn't all bad, but really it's done (putting the MAF after the turbo) as ease of use.
Once a person shifts and the bov opens up, a rich condition will be seen.
Most setup as picture above, should be setup as a recirculated setup, since the maf has already accounted for the air. If it gets vented to Atmosphere, then you're simply telling the ecu I calculated x amount of air coming in per the MAF, so the ecu allows for the appropriate fuel to go in for that x amount of air, yet, you're letting some of it out, resulting in a rich condition.
|NO the MAF does NOT figure out how much air is coming through by the Air's TEMP. It calculates by how much COOLING is being done to the hot-wire inside by the air passing over it, and how much AMPERAGE it takes to keep said wire at that a specific temperature!|
|OE manufacturers place MAF pull through for the simple fact that it operates on air movement across the wire, not pressurized air being placed around it|
YES, I DO run a PULL through MAF
NO the MAF does NOT figure out how much air is coming through by the Air's TEMP. It calculates by how much COOLING is being done to the hot-wire inside by the air passing over it, and how much AMPERAGE it takes to keep said wire at that a specific temperature!
-- Just like how a WIDEBAND A/F meter uses AMPERAGE to pump O2 in or out of the nerst cell to figure out what actual A/F is --
Seriously, I'm not a newb at this, and please don't try to talk to me as such. If you want to have a conversation, lets ... and i can back all my findings with everything with firsthand experience, not regurgitated info.
-- If you would please, Get an OBD2 Scan tool and use it in live data to tell me what your MAF's lb/min reading is at WOT in full boost. Mine is reading around 36-38 Lb/min.
Furthermore -- OE manufacturers place MAF pull through for the simple fact that it operates on air movement across the wire, not pressurized air being placed around it -- for an example, please refer to stock GTE MAF placement. ~ I don't know about you, but sitting in a hot room with stagnant air on a hot day makes me feel hot. Even if that room was pressurized, i'd still feel hot, maybe hotter ... when i turn a fan on i feel cooler as air moves across my skin and picks-up/removes heat from my body. Boosted air is stagnant ~ yes there is FLOW, but not enough that the wire can see and effectively be cooled, to give an accurate reading.
Also about hesitation --- on pre-turbo setups, its cause when the air passes back over the wire (in reverse) when the Throttle plate closes/bov closes, and the turbo is in Decel. Stock GTE MAF's have a hooded hotwire to prevent the re-pass over of AIR across the wire in these instances. Also, hesitation and Stall on pre-turbo MAF's is due to improper tuning and a poorly setup MAF clamp. When the BOV opens, the MAF sees a RUSH of what it believes to be "engine consumed" air and tries to compensate by dumping in more fuel to prevent a lean condition ~ thus a stall due to an overly rich condition because the engine did NOT infact consume the air, and actually need litte/no fuel because is in Decel, or maybe already at idle ... again a properly setup MAF clamp cures this.
pull through by-far yields best drive abilty and tune ability in and out of boost with the right know how and tuning.
blow through is simple, and requires little in the form of tuning out stalls and other slight hiccups because it doesn't ever get the chance to see whats happening before it -- blow through is EASY but shouldnt be recommended. - I actually feel that "kits" are sold with Blow-Through setups for EASE of sending a pre-configured ECU out with the setup. Every care is going to require a custom MAF Clamp that cannot be summed up in a general tune. therefore, set everyone up with a tune/kit that doesnt require such customization/headache.
Blow Through Pros DISPUTED
- Fastest A/F Ratio Changes
The MAF will interpret the pressure change/lack of are movement/velocity as a DECREASE of AIR consumption by the engine, and REMOVE fuel.
- More Accurate
WRONG .. the MAF becomes LESS accurate as velocity across the hot wire is reduced. Again, velocity across the wire yields MORE cooling thus MORE air volume. pressurizing the air around the wire does NOT constitute more wire cooling, it in fact does the opposite.
- Eliminates 99% of Idle Problems
Yes, because the MAF doesn't know the difference between stock and the turbo being added
- Meters Exactly how much Air is Going into the Motor, not how much is in the Intake.
WRONG ... read the above.
- Easier to use Blow Off Valve
I think you get the idea of why. MAF doesnt have a chance to read the air that escapes the BOV - and thus does NOT for the ECU to dump fuel.
- Can use Atmospheric Blow Off Valve
Ditto the above
- Totally Eliminates Recirculation Setups
Blah blah blah .. same "pro" recited 4 different ways
My turn to ask YOU now. Have you ever ran a Pull through setup and experienced this phenomenon for yourself? I have actually NEVER.
ALL as i mentioned earlier -- and this quote was taken from your poor selection of threads to link. I actually read that thread AFTER writing this whole post.
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