intake piping q.

[mattro]

im using a custom intake before the turbo.

here are my options/ set up.

filter-maf-custom pipe-turbo

or blow thu

filter- custom pipe- turbo- maf

here is my q.

on the stock det intake right after the maf there is a rubber hose that has a vent, if i run the maf before the turbo i have to have one but if i run blow though i dont need a vent? or do i?

also what is the purpose of this vent? (its like a 1/2 inch nippe that a hose goes on and i dont remember where the other end goes.)

[waynehead05]

That sounds like the recirculation for the catch can. I would still recirc it AFTER the MAF if I were you even if you're going blow through.

[s14unimog]

For one, its definitely not a vent. That is the WOT vacuum source for the crank case. In the stock orientation, that nipple would be connected by a formed hose to the VC "T" fitting; which connects to the oil separator tank and the block. If you plan to switch to blow through, you would still need to have this connection. Not only do you still need it for the crank ventilation, that would be a source for unfiltered air to enter the turbo. Personally, I'm not a big fan of blow through. The factory MAFS was never designed to be in a pressure situation and you'll run into countless problems with sealing the charge system b/c of it. Also, since it will be inline on the charge system, you run the risk of reading air twice. When you let off, i.e. close the throttle body, most of the air will escape through the BOV but the in line MAFS will see some turbulence back flowing through the charge system. Not only that, unless your turbo passes zero oil, you run the risk of coating the MAFS sensor with oil.

If you want to avoid stalling, recirculate.

[mattro]

For one, its definitely not a vent. That is the WOT vacuum source for the crank case. In the stock orientation, that nipple would be connected by a formed hose to the VC "T" fitting; which connects to the oil separator tank and the block. If you plan to switch to blow through, you would still need to have this connection. Not only do you still need it for the crank ventilation, that would be a source for unfiltered air to enter the turbo. Personally, I'm not a big fan of blow through. The factory MAFS was never designed to be in a pressure situation and you'll run into countless problems with sealing the charge system b/c of it. Also, since it will be inline on the charge system, you run the risk of reading air twice. When you let off, i.e. close the throttle body, most of the air will escape through the BOV but the in line MAFS will see some turbulence back flowing through the charge system. Not only that, unless your turbo passes zero oil, you run the risk of coating the MAFS sensor with oil.

If you want to avoid stalling, recirculate.


i know its not a vent, i meant nipple that a hose goes on.

and thanks very much that cleared up a lot. i will be def running a the standard maf set up (not blow through) i may still have some questions though. ill let u guys know if i do.

thanks again it really helped