tjkj2002 wrote:
You will loose any HP from that setup in the amps that is drwan from the alternator which makes the engine work harder and robbing more power from it.
Your turbocharged already,not going to get any better.
X2
Opening up the exhaust all the way to 2 1/2" will do as much as the stock turbo can handle. Make sure you get rid of the choke flange on the back of the Soot Fryer (CAT). The choke flange on the back of the CAT produces up to 5 PSI of back pressure with a stock muffler and 0.0PSI with the CAT in tact, straight through muffler and the choke flange opened up to 2 1/2 inches.
I heard of one guy that mounted a manometer like what they use to measure the pressure for natural gas valve adjustment for furnaces in the cab and ran a line to the air box. Then he screwed around putting holes in the air box until there was no air box vacuum.
In most automotive applications we measure vacuum in inches of mercury, manometers for furnace gas valve adjustment are calibrated in inches of water (much lighter).
Now if you want to do calculations: 14.7 PSI = 1 BAR =384 inches of water = 9.75 Meters = ~30 inches of mercury. My guess is that if you play around with the air box, you will be lucky to get rid of ~1-2 inches of water vacuum.