Originally posted by fastcougar:
Originally posted by Stazi:
Correct: PCV should be direct to the intake maifold and the valve cover to the intake pipe BEFORE the turbo (after the MAF)

Just like stock ... the turbo should fit into the stock intake system between the throttle body and the "Idle Air Bypass Tube" correct?



No. The IAC bypass tube must be on the pressure side of the turbo as it will leak down pressure back into the low pressure side of the turbo. It also may damage the plunger.

You aren't using the IAC under load and definitely not under boost, so you want no pressure differential across it except at idle. At idle that would be controlled by the TB and the turbo would play no part in that.
So:
-PCV outlet into the manifold after the TB plate.

-Valve cover vent after the MAF and before the turbo compressor inlet.

-IAC tube after the turbo but before the throttlebody. Put it after the intercooler core if you have room, right next to your IAT sensor.

- Wastegate vacuum/pressure should be tapped right before the throttlebody, after the intercooler if you want to compensate for the pressure drop of the intercooler assembly before you open up the gate. This means that tapping off the turbo will open the turbo when the exducer pressure hits the same as the spring pressure. Then you will get a pressure drop across the intercooler and you will see lower pressure than your wastegate setting...most likely. If you do it after, then whatever pressure is hitting the throttle plate is applied to the wastegate, somewhat eliminating the pressure drop of the intercooler. Not a big deal either way, but worthy of mention and usefull if you don't use a boost controller.

- Blow-off should be tapped right after the throttlebody plate, same as the power brake booster and related vacuum lines.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black