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Posted: May 16th, 2006, 10:16 pm
by Jacbs2007
BuGS wrote:ahahahahahaha that picture is extremely funny. Wastegate is for EXHAUST gasses, not measured intake HAHAHAH
Well thanks for laughing at me, and the reason I included that in the picture was so ppl didn't ask "well do I need a wastegate then...since it's not in the picture? er durr" and yes thank you, I'm pretty sure we all know that the exhaust air never mixes with the air that ends up in our throttle bottle, it just spins the turbine.
-Curt-
Posted: May 16th, 2006, 10:27 pm
by Bochek
XxantwawnxX wrote:Look above i changed it, and thats hwo it works. so disregared my first statement.
XxantwawnxX wrote:A mass airflow sensor does the job of a volum airflow sensor and an air temperature sensor. It measures air MASS. The mass of a given amount of air is calculated by multtiplying its volume by its desnsity.
the mass airflow sensor converts air flowing past a heated sensing element into an electrical sensor. The strength of its signal is determined by the enregy needed to keep the element at a constant temperature above the incming ambiant air. As the volum and density (mass) of airflow across the heated element changes, the temp of the elemnt is affected and the current flow to the element is adjusted to maintain the desired temp of the heating element. The varying curent flow paralles the particular characteristics of the air (hot,dry,cold,humid,high/low pressure)
this still doesnt answer our question on if you can put a flaper style maf after the turbo or not. lets not forget the point of this thread.
Bochek
Posted: May 16th, 2006, 10:41 pm
by XxantwawnxX
If it has a flapper its a VAF as far as i know there are only two basic types of MAF sensors , Heated wire and hot film type. But yea as far as a Volume/vane Air Flow after the turbo...i would assume you can.
Posted: May 16th, 2006, 10:50 pm
by Bochek
XxantwawnxX wrote:If it has a flapper its a VAF as far as i know there are only two basic types of MAF sensors , Heated wire and hot film type. But yea as far as a Volume/vane Air Flow after the turbo...i would assume you can.
but isnt the sohc I4 a flaper style, and called a MAF?
Bochek
Posted: May 16th, 2006, 10:53 pm
by XxantwawnxX
Im not sure, if its called a MAF and has a flapper. According from what i learned in class MAF are only those two types i mentioned. Flapper styles cant measure mass. But there can alwasy be exceptions i guess. Flappers only measure airflow or volume, not mass. So i dont think it would be called a Mass Air Flow sensor...unleess its like some kinda hybrid that does both...
Posted: May 16th, 2006, 11:00 pm
by Bochek
XxantwawnxX wrote:Im not sure, if its called a MAF and has a flapper. According from what i learned in class MAF are only those two types i mentioned. Flapper styles cant measure mass. But there can alwasy be exceptions i guess. Flappers only measure airflow or volume, not mass. So i dont think it would be called a Mass Air Flow sensor...unleess its like some kinda hybrid that does both...
its time for me to go on a knowledge hunt and annoy the hell outta everyone i know that might know something about this.
Bochek
Posted: May 16th, 2006, 11:02 pm
by XxantwawnxX
HAHA yea i actually do that alot too. Let me know what ya dig up, im curious.
Posted: May 17th, 2006, 12:12 am
by ariesdude
I think the flapper type in SOHC is called MAF because it estimates the mass of incoming air. It has an extra temperature sensor for the intake air. This temperature value at atmospheric pressure could be used to calculate the density of the air. The trap door already calculates volume. Mass = density * volume
IMO The trap door type sensor (without spring modification) may not be suitable after turbo because the door could be kept open by air pressure which will tell the ecu that more air is going in than actual.
Posted: May 17th, 2006, 12:18 am
by XxantwawnxX
ariesdude wrote:I think the flapper type in SOHC is called MAF because it estimates the mass of incoming air. It has an extra temperature sensor for the intake air. This temperature value at atmospheric pressure could be used to calculate the density of the air. The trap door already calculates volume. Mass = density * volume
IMO The trap door type sensor (without spring modification) may not be suitable after turbo because the door could be kept open by air pressure which will tell the ecu that more air is going in than actual.
I know some Flapper styles have a bypass passage for high pressure situations(normally backfire to the intakemanifold) not sure if it would work for boost.
Posted: May 20th, 2006, 9:58 am
by ModMX3 - (Carmaster2005)
WOW never knew such a simple question could get so in depth. You guys are all very smart in this subject area. Im sure someone will have a definete anwser.down to the last thing on my list that I need for this turbo setup, The mainfold !
My setup will be on a B6 DOHC
323 Manifold
VJ-11 turbo - running 6/12 PSI using solinoid switch
Vortex adj. FMU
310 cc probe injectors
Mr-2 SMIC
2.5 inch Charge Plumbing
2.5 inch performance downpipe
8.5 mm Magnacore wires
Stock Modified BOV
HKS - Boost controller
Timex - Boost/Temp Gauge
I will be using this setup( very similar to others ) with the MAF mounted befor the turbo and ill let everyone know how this works, on this type of setup , dealing with lean/ rich conditions.
Posted: May 23rd, 2006, 9:46 pm
by Joey's mx
ok again what would be the best placwe to run a DOHC type maf(hot wire)
Will the boost pressure blow the maf after the turbo??
Posted: May 24th, 2006, 4:26 pm
by cjthor
Joey's mx wrote:ok again what would be the best placwe to run a DOHC type maf(hot wire)
Will the boost pressure blow the maf after the turbo??
on the DOHC four put the MAF before the turbo. it is not made for boosted applications. you will screw it up and it will not work if you put it after the turbo
Posted: May 24th, 2006, 5:45 pm
by Joey's mx
ok thank you!! That is what i thought when looking at the tinny wires on the inside of it!!!
Posted: April 15th, 2007, 3:34 am
by Ricardo
I am using the MAf after the intercooler and after the BOV, under pressure, at 14PSI and it hasn´t blown so far, this setup has about 1 year.
Posted: April 17th, 2007, 1:43 am
by osargeant
Hi Ricardo,
Were you ever running the MAF before the turbo and if so, what is the difference between then and now you are running it after the intercooler and BOV.
I am very interested in the results since I always heard it was risky putting boost pressure through a MAF.