blow valve with MAF??

[Joey's mx]

I was talking to a guy yesturday and he said I cant run a blow off valve because my engine has a mass air flow sensor...is that true?? I have seen some DOHC B6 motor boosted with blow off valves..so whats the deal??

[fieromx3]

that makes no sense u can have a bov with a maf but i dunno if ur supposed to have it after or b4 the maf but i am guessing b4 the maf so it don screw up the a/f mixture

[Joey's mx]

well the way i see it done is pipe from intercooler to throttle body has the blow off valve on it....and the pipe from the turbo to the filter has the mass air flow sensor on it!!!

[Josh]

thats a crock of crap. you just cant run your BOV open to the atmosphere. you have to run it back in line before the MAF.

But that all depends on where you put your MAF. now if you put your MAF after your IC just before your TB, then you can run your BOV open to atmosphere. the BOV just has to be before the MAF. that way the MAF wont read the loss in air. other wise it will think you have a vacume leak, and your idle will fluctuate.

[Joey's mx]

so it whould have to go .....trottle body-MAF-BOV-intercooler??

[fieromx3]

yes

[D323]

NO. You want the BOV as close to 6in to the TB.

It should go TB, BOV, VAF/MAF the IC.

The BOV is to protect the cold side of the turbo. When the TB closes the air bounces back, and BOV is there to release the pressure to protect the cold side.

You dont want air flowing the wrong way through the MAF/VAF. That will mess up you a/f as said.

[fieromx3]

ok that actually makes more sense. i had the right idea but more to it.

[Joey's mx]

so it wouldnt work right if i put the MAF between the turbo and the filter....and the blow off valve between the throttle body and the intercooler!!

Because i was looking at the mx-3 from 2 fast 2 furious the same set up as what i am doing and that is how his is set up!!

Here is that page i am looking at:
http://www.cardomain.com/ride/282371/2

[fieromx3]

double posted accidentally

[nos92mx3]

If you want to vent your Bov and not have a problem with idle it needs to go.

Intercooler-->BOV-->Maf/Vaf-->Throttle body.

But heres another arguement for you.
Why do you want to Bov as close to the throttle body? Wouldnt it make more sense to place it before the intercooler? So the intercooler isnt doing as much work to cool the air.
it dosent make much sense to me to vent cool air, id rather vent hot air.

[Joey's mx]

Ok can poeple who have turbo set ups on there DOHC B6's please post pictures of there engines because this is getting really confusing!!!

[XxantwawnxX]

To work right it has to go BOV----> MAF/VAF------>TB becauseif you put the BOF after the MAF the MAF well measure the amount of air and such liek its suppose to...but then ur BOV well let some of that measured air out...giveing ur comp false readings.

[Josh]

To work with the MAF for an atmospheric BOV you have to go

Filter-> Turbo-> IC-> BOV-> MAF-> TB
this way the MAF wont read the loss in air.

to run it properly with the MAF as if it wre stock it needs to be

Filter-> MAF-> Turbo-> IC-> BOV-> TB
and you cant run it this way with the BOV to atmosphere, as the maf reads the drop in air. so you have to re rout the exit off of the BOV into the piping somewhere after the MAF and Before the Turbo.

and it really doesent matter where the BOV is located, as your piping has constant presure. alot of subarus and Volvos come with the BOV mounted to the IC. its all personal preferance

[Joey's mx]

Ok understood now....but why is it that the mx-3 form 2 fast 2 furious has his MAF between the filter and the turbo??