E46Fanatics - View Single Post - NOEL COMES IN FOR THE HPF Stage 2 w/6766 and OPEN DUMP
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Old 12-19-2012, 08:22 PM   #146
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Join Date: Dec 2007
Location: Overland Park, KS
Posts: 371
My Ride: '03 330i ZHP Sedan
Originally Posted by nnacpil View Post
Would that cause my wg to not open at all
Yeah, think of your wastegate duty cycle like injector duty cycle. Increase the IDC and you spray more fuel. Increase the Wastegate Duty Cycle and you bleed more pressure through to the wastegate which opens it faster and wider.

The boost spikes are because the duty cycle is too low and the wastegate is too slow to respond, so the boost spikes before the gate opens all the way.

You get boost creep from the gate not being open far enough and it doesn't bleed off enough exhaust gasses.

At least, that's how I understand it.

Last edited by Scooby24; 12-19-2012 at 08:24 PM.
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