venting your bov

[DSMPagano]

I am a little confused on the blow through and draw through setup for the gm 3 mas and translator. I know that for blow through you put the mas between the TB and bov. Then you can take the tube off of the bov and vent into the atmosphere. I might be slightly off on that. I was wonding why you can't vent with a draw through setup? I just received the mas/translator combo in the mail and want to know what way to run it. It wouldn't be out of the question for me to cut my intercooler pipe and make it blowthrough i just don't want to if i don't need to(using a sawsall is fun though) Any information would be great thank you.

 

[LaN-]

i'm no expert but draw through is having the MAS before the BOV on the intake, this way the computer reads all the air entering the turbo and tells the computer how much fuel to add. By venting this way the computer is losing air that it thinks it has but doesnt causing all the known problems with venting.

blow through on the other hand has the MAS behind the BOV so it only reads the air entering the intake Mani allowing the computer to do its job right.

if you dont want to touch your UICP then you cant vent

Again i'm not expert so do some searching on this first.

 

[Lordpaxin]

right on.

blowthough is what all the hype is about. whats the point of spending 200$ on a Maf translator and 50$ for a 3 inch maf if you cant go PSSSSSSSHHHHHTTTT

To avoid the problems with venting (metered air exiting the system causing a rich situation because the computer adds fuel for air that isnt there) you setitup in blow through. the MAF sensor between the bov and intake, so when you blow off that presssure, it passes through the sensor first. and get taken out of the formula

 

[Lordpaxin]

here is my old setup in "blow through"

 

[DSMPagano]

thanks those answers really helped a lot. i think i am going to make it blow through. i think if i can put on the turbo and everything myself i can handle this job also. I have the dejon tool upper intercooler pipe like in the picture so my set up will look similar. thank you very much everyone.

 

[99gst_racer]

Very good posts gentleman. Here's my quick stab at your question.

Basically, once the air passes through the MAS, it besomes metered. After that point, the air cannot escape the intake tract. If you blow the air off through the BOV or if you have a leak after the air is metered, then you will run rich.

In MAFT blow-thru, the MAS is after the BOV, so the air that it is blowing off is not yet metered, thereby having no affect on the engine's tune.

 

[project_tsi]

here is my setup in blowthrough.

 

[talondude4]

That bov looks like a horn

Is that a turbo xs blow off valve?

If so i herd they leak at like 16psi is this true?

 

[99gst_racer]

That bov looks like a horn

Is that a turbo xs blow off valve?

If so i herd they leak at like 16psi is this true?

He's running 25 PSI with no leak. I'm not a fan of the Turbo XS bov's either, but it's holding it's own so far. it's usually a combination of high boost and time that make them leak......

 

[project_tsi]

Yes, that is the Turbo XS RFL. I personally don't like this brand either, but it was free to me and thats why I use it. If I were to buy another one (which I plan on doing later) It will probably be Type S or posibly a Tial 50mm, depending on the results that I find out about it. Yes, right now it does hold its own. But I've gone and replaced the seals (o-rings) as well as cleaned the unit multiple times and added washers for correct spring rate.

 

[assa 98gsx]

right on.

blowthough is what all the hype is about. whats the point of spending 200$ on a Maf translator and 50$ for a 3 inch maf if you cant go PSSSSSSSHHHHHTTTT

To avoid the problems with venting (metered air exiting the system causing a rich situation because the computer adds fuel for air that isnt there) you setitup in blow through. the MAF sensor between the bov and intake, so when you blow off that presssure, it passes through the sensor first. and get taken out of the formula

It's not just spend those money to have a cool sounding effect. 2G MAS can easily be overrun by a 50 or 60trim turbo at high boost. To avoid overrunning the stock MAS, people go with the GM MAF, venting is just one of the extra bonus.

 

[Lordpaxin]

I know this.

my point was with the origional topic, comparing blowthrough with draw through.
if you have it, might aswell go pssshhhht

 

[project_tsi]

I know this.

my point was with the origional topic, comparing blowthrough with draw through.
if you have it, might aswell go pssshhhht

Id do it for the better metered air, and the quicker turbo response, etc. Rather than the Pssshtttt.

 

[DSMPagano]

when you do the blowthrough design how do you plug off the whole on the turbo side. I'm talking about the hose that goes from the bov to the turbo. When you take it off how do you go about plugging the whole on the turbo? Thanks for the help

 

[blackGSX2g]

Id do it for the better metered air, and the quicker turbo response, etc. Rather than the Pssshtttt.

Not to mention being able to continue to drive after you pop off an IC coupler. I've enjoyed that bonus many times over.

 

[project_tsi]

Ive actually done it a few ways. One way I did was leave on the hose and stick a piece of wood in there and put a hose clamp on. The I took one of my 1Ga headlight motor covers and stuck i ton the metal tube and used a hose clamp. Then I took off the pipe, cut it off, and welded a peice of steel to it, and repainted the intake tube.

 

[project_tsi]

Not to mention being able to continue to drive after you pop off an IC coupler. I've enjoyed that bonus many times over.

Yeah Ive done that one a few times also.

 

[Lordpaxin]

gosh.......

I never once said the purpose of the MAFT was to go pssssshhhhttt....... ok?

the WHOLE reason I SAID IT was comparing blow to draw through. where blowing through the mofo you can go pshhhht so you might as well DO IT AHHHH MAKE IT STOP AFKJDFDSJKFSDFKJSDJKFNFNSNVN

 

[sciroccosven]

Very good posts gentleman. Here's my quick stab at your question.

Basically, once the air passes through the MAS, it besomes metered. After that point, the air cannot escape the intake tract. If you blow the air off through the BOV or if you have a leak after the air is metered, then you will run rich.

In MAFT blow-thru, the MAS is after the BOV, so the air that it is blowing off is not yet metered, thereby having no affect on the engine's tune.

Nicely put, having blowoff past the mas is essentially having a vacume leak. If you are going to run a bypass valve then the most efficient way would be to run the line back to the hotside of the intercooler that way the air is going through the intercooler twice without going through the turbo. You are not losing any air in your system and you are actually making the air slightly cooler, very slightly. If you just shoot it off in to the atmosphere your turbo will have to replace the air which means your intercooler is going to have to cool more air.

 

[DSMPagano]

project tsi there were a few spelling mistakes that make it hard to understand what you were saying about how to block off the whole on the turbo when you take off the hose from the bov in blowthrough design. can you or some one else explain again please its the only thing i still don't understand about the design. thank again
this is not meant to be a diss or nothing to you project tsi I'm just interested in knowing.

 

[project_tsi]

project tsi there were a few spelling mistakes that make it hard to understand what you were saying about how to block off the whole on the turbo when you take off the hose from the bov in blowthrough design. can you or some one else explain again please its the only thing i still don't understand about the design. thank again
this is not meant to be a diss or nothing to you project tsi I'm just interested in knowing.

Ok here are examples of my old setup and my new setup. In the 1st pic, you can see that I just stuck a small peice of wood, that I cut off a rake, and plugged the hole, then used a hose clamp. I don't have a pic of the light motor cover that I used.
In the 2nd pic, you can see the black pipe, its the same red pipe, but I cut off the BOV return pipe and welded it shut w/ a piece of steel, and painted it black. You can't even see where the pipe was anymore!

Both pics are mine, and show my old setup and newer setup.

 

[DSMPagano]

thank you that makes perfect sense now the pictures really helps thanks for putting in the time.

 

[gamingguru]

Or, if you really want to go all out you can convert to MAP instead of MAF. Like this:

 

[ETK-kAos]

Or, if you really want to go all out you can convert to MAP instead of MAF. Like this:

What are advantages of coverting to MAP instead of MAF?

 

[gamingguru]

You don't have the restriction of a Maf sensor so can can theoretical spool your turbo faster. And most impotently of all, it looks really really cool.