Wastegated VGT

MarkBroviak

DMax Junkie
May 25, 2008
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Danville Indiana
I wonder if there is a way to adjust a waste gate to follow RPMs , where if you were running the 72mm vgt at lower RPMs where drive pressure is more of a concern , it would release pressure and gradually as RPMs rise the gate would follow to be fully closed at say 2500 RPMs to make use of the larger vgt top end , Or just stick with a 68 stg2r and be happy ?

Honestly stick with stg2R and you'd be happy. Wastegates are great in the gas world but seem to cause more headaches than anything for the diesels since we aren't as concerned with how much boost we produce. As soon as you open a gate you are dumping drive and you will drop shaft speed so it is a lose-lose situation honestly and that's why it is called a wastegate. You are wasting the energy to drive the turbo. It would be easier to control drive by throwing less fuel at it. Timing can change it also. Advance the timing and you put the heat in the cylinder and increase cylinder pressure but you lose the expansion heat in the exhaust and drive will drop. Pick your poison so to speak. I'm on the other side of the fence on this one as I would prefer to put the heat into the exhaust to drive the turbos harder without beating on the motor as much. That's a completely different discussion all together though.