Open bov at idle= way lean because you're drawing air that the maf is NOT accounting for. So guess what. You draw in a lot more air. With the same amount of fuel supply. Doesn't take a genius to figure that out. Yes i know the turbo spins at idle.(vaccum from the cold side helps it spin as well, this goes away a bit after you lose vaccum in the i/c and piping. But not even close to what's needed to get out of a vaccum condition. Essentially you have a huge vaccum leak at idle. NOT GOOD.

VTA bov between shifts= you go way richh. Why you ask? Because you just dumped a **** load of air(especially with that 50mm) out into the atmosphere instead of back into your intake tract. Hmmmmm, so the air flow your maf has already accounted for and has adjusted your fuel supply accordingly for has now taken a detour out to the land of no return. Yupp, doesn't take pure brilliance to figure that out either.

 

You are completely wrong on the open BOV at idle. You will run rich because you have more air going through the MAF than is making it to the engine. The upper intercooler piping is under positive pressure at idle and the open BOV is letting air out, not drawing it in.

 

actually, the air is moving out of the valve, it's not being sucked in

to the thread starter...are you running the stock bov line? if so that is your issue...get 1/4" ID line that is reinforced and run it ALL the way to the manifold, do NOT hook it to where the stock bov connects to a smaller line by the valve cover. that seems to be the cause of the problem with evo's 98% of the time

 

Since we all are here lol, I have a Tial the version from last year the new 50mm and I am on my MAF but no stalling and no idle issue really except under lite throttle the Tial stays open for like 3-5 sec and then shuts and I was told that will kill my gas mileage and it needs to be replaced.This being told to me by DTM and I trust them but is there a way to allow me to keep it and have it close properly? I got this on the car so spring have no clue whats inside and how its hooked up huh yeah sure not a a clue.

 

im running stock boost. i dont have a boots controler on it yet, and im in iraq so i cant instal it. basically which spring is best to use for stock boost application. i have no way of telling the vac at idle.

 

big typo for my last post. i dont have a boost guage on it yet, so i cant tell what the vacuum is at idle. which lb spring do people recommend for stock boost settings

 

Why u guys using a Tial BOV for OEM boost or slightly higher? Go with a OEM 9 DV and call it a day. Is everyone going the ricer mod these days?

 

ricer mod huh? actually no. im in iraq and uhh my car will be going in the shop for major major mods. will be puttin my car in the tens easily. which is why im going with tial. i will not be on stock ecu. now does that make sense to you? ask what future plans are before you try to be funny

 

in case anyone wants to see my flyby, here is the link. please comment, thanks
http://www.youtube.com/watch?v=WF7xeX8ye1c

 

i am running the tial on mine with the 9lbs spring. i love it, it holds all of my boost and it doesnt leak at all. i find that feathering of the gas it does surge some, but i dont have an issue when i let off the gas hard.