Holset vgt 6.9 idi build thread

[bradroche]

Im a mack shop mechanic actually a foreman now but im basicly designing the vane control off an e7 mack 350/427/460 they all use a vgt turbo with a swinging linear actuator. basicly the way the circuit works for the electrics on those trucks is very simple yet over engineered .the engine supplys constant oil pressure to a valve that is electronicly controlled by the ecm based on overboost,backpressure,and cool ambient air temps, all in series if one states the vanes need to move the valve limiting the oil pressure going to the hydraulic actuator which is returns via internal spring blah blah blah i dont want to expain how this over engineered system is saving the ozone but with all that said im stealing the idea of using the signaled actuator but eliminating the oil pressure side of thing. i plan on putting a 25 lb pressure switch for back pressure, and a 10lb pressure switch for the boost side to open the vanes

 

[bradroche]

my problem with my system is that the macks use oil pressure metering valve so they can achieve endless intermediate vane positions while unless i can develop a system of potentiometers ill will be stuck with only two vane positions fully open and fully closed,and the only intermediate position will be while the vanes are opening and closing. its all a theory! i need to remake my actuator to achieve a better fulcrum to achieve fully open and fully closed on the turbo being the vane lever moves 1/2 inch and the actuator is a 2 inch throw ill need to make some ajustments

 

[laserjock]

The answer is to switch from a pair of switches and use sensors and a microcontroller with a map like you would find on a fueling map for a EFI system. Just map vane position verus pressure, boost, etc and you should have no problem with achieving full adjustablity. You have to have a sensor on the actuator to give you position feedback and then read what ever other inputs you need. A raspberry pi or arduino would probably do it and it would be fairly simple.

Is it all worth it... I have no idea but that's how I would approach the problem.

 

[bradroche]

Painted the truck piped the cHargett tubes direct to the na intake manifold going to fab a collector similar to the ats snail style collector. For now so I can start driving the truck I'm putting the accuator to a two way switch so I can close or open them depending where I'm dribing. And when I get to a cruising speed I can just open them I picked up an ajustable externally exhausting wastegate so It will dump drive pressure incase I over boost for safety of my headgaskets it'll be a good show to take it on a first drive