Bov Venting

[GSX93DSM]

I have a question. Is it worth putting my maf up into my intercooler piping and leave the bov to venting into atmosphere.

 

[FORMONTOYA]

You have been here far too long to even ask this question...................


Short answer.......No.

Long answer........The only way to truly and correctly vent your BOV is by using the MAF-T along with the GM sensor in a "blow-through" setup.

 

[DGajre777]

I have a question. Is it worth putting my maf up into my intercooler piping and leave the bov to venting into atmosphere.

The only way you can properly vent is to have the MAF AFTER the blow off valve, if you want to vent. This is why people install GM MAFs and MAFT after the blow off valve. If you want to fabricate an upper intercooler pipe where the stock 1G MAF/MAS is after the blow off valve, yes you can go for it.

 

[GSX93DSM]

I figured just wanted other opinions thanks

 

[FORMONTOYA]

I would like to see the 1G/2G MAS handle any real boost pressure and NOT fly to pieces, or NOT blow a section of honeycombs into the intake.

Yes, the GM sensor would have to be after the BOV.

 

[DSM90AWD]

I would like to see the 1G/2G MAS handle any real boost pressure and NOT fly to pieces, or NOT blow a section of honeycombs into the intake.

Crap! And I thought I was onto something too

 

[oldman]

If you want to fabricate an upper intercooler pipe where the stock 1G MAF/MAS is after the blow off valve, yes you can go for it.

Dee, I hope you're NOT suggesting he can run stock mafs in blow through.

 

[DGajre777]

I would like to see the 1G/2G MAS handle any real boost pressure and NOT fly to pieces, or NOT blow a section of honeycombs into the intake.

Are you serious? Have you heard of any honeycombs falling in the intake at high boost pressures? What can the stock MAS handle, as in psi? And what about taking the honeycomb out?

 

[DGajre777]

Dee, I hope you're NOT suggesting he can run stock mafs in blow through.

If he fabricates something and moves the stock MAF after the blow off valve on the upper intercooler pipe, why wouldn't he be able to? It'll be like using a GM/MAFT setup after the blow off valve but using the stock 2G MAS instead. I haven't seen anyone do it, but I didn't really know why anyone hasn't done it.

 

[oldman]

Dee, I corrected my post, left out the word "not". The stock mafs see no positive pressure because it's mounted before turbo, Jim is right.

 

[FORMONTOYA]

The OEM MAS on the 1G/2G is designed to go before the turbo, that is to have the air "sucked" past the metering element. There is no pressure inside the MAS, if anything there would be a vacuum inside the MAS. Velocity of the air is not too important in this situation........up to a point.

Now turn it around and start to blow through it, especially under boost conditions and you're starting to expand the "case" of the MAS, something it was NOT designed to do. Even if it didn't catastrophically blow apart, it would surly start to leak in some odd places. If the "case" expanded enough, then yes, the honeycombs could conceivably come loose and get "pushed" into the intake/motor where the air velocity would play a bigger role. It sure wouldn't be pretty.

I have not done it or know of anyone who has............my opinion is only from a design standpoint as that's what I do for a living......mechanical design.

 

[DGajre777]

Dee, I corrected my post, left out the word "not". The stock mafs see no positive pressure because it's mounted before turbo, Jim is right.

Damn! I'm brain dead today. Yeah, I forgot about the stock MAF not seeing any positive pressure because it is mounted before the turbo, all it will see is airflow, not boost.

But after the turbo, what FORMONTOYA said makes good sense.

 

[TURB0]

Yeah, I would just invest in a MAFT blow-thru setup. They are affordable, and I haven't regretted buying mine to date.

 

[DSM90AWD]

If he fabricates something and moves the stock MAF after the blow off valve on the upper intercooler pipe, why wouldn't he be able to? It'll be like using a GM/MAFT setup after the blow off valve but using the stock 2G MAS instead. I haven't seen anyone do it, but I didn't really know why anyone hasn't done it.

The 1G/2G MAFs count "vorticies" that pass thru the metering section of which the honeycombs help smooth airflow into. The ECU then takes that information and combines it with the pressure and temperature readings the MAF sends it (lightbulbs going off) to calculate MAS Air Flow.

The ECU also uses intake temperature at the MAS in some of it's timing routines (e.g. above a certain temp and timing advance is affected) so heatsoak/poor intercooling would play havak. Not to mention the turbulant air crashing into the huge obstruction in the UIP (the MAS) at near Mach1 speeds would not yield very accurate "vortice" reading.

The MAFT uses a hotwire system (airflow based on resistance change in the wire) to determine air mass and sends the ECU "hard coded" Temp and Barometric values as such can be placed before/after the turbo

 

[oldman]

Yeah, I would just invest in a MAFT blow-thru setup. They are affordable, and I haven't regretted buying mine to date.

For tuning yes but for venting, definitely not. Even for tuning, it's at the bottom of the list.

 

[Defiant]

Odd that no one had ever asked this on this board before.

Or, that this thread lasted through 16 replies.