So I had an 03 tdi with a vnt17/22 and a forge Motorsport actuator. From what I understand the actuator had 2 chambers one side with vacuum and the other with boost. Vacuum increases boost and boost decreases boost. I think. I would like to put a vnt 17 on my 1.6 idi. I'm just curious about running vnt on it without some standalone vnt controller.
So if I tied in the vacuum sys to the vacuum port via a boost controller and a throttle actuated valve between the pump and the boost controller (so in order from the vacuum pump. vac pump, small pneumatic valve actuated by the throttle, boost controller/ air bleeder, the vacuum port on the wastegate.
for the boost side it will be just a boost controller between the manifold and the boost side.
I believe with proper vacuum valve rigging to the throttle, vnt actuator spring and rig, and experimenting with bleeding I believe the vnt should work as advertised. I'm just a little turbo diesel rusty. I had some serious gas cars for a while and now I plan to build another powerful and drivable diesel now just an older one.
Does anyone know of this has a remote chance of working?
I've discussed this concept with several other people and feel that it is very viable although I believe you have it listed wrong. Vacuum on one side of the actuator diaphragm would decrease boost, boost on the other side would push in the same direction as the vac pulled and so would also decrease boost. As mentioned, get a dual actuator. I would also recommend getting a vacuum valve off an '80s Mercedes TD or similar. The Merz valve allows full vacuum when the accelerator is at idle and progressively reduces the vacuum as the accelerator is depressed. With vacuum hooked through the vacuum valve to the vac side of the actuator, then at idle and full vacuum would open the vanes. As the pedal is depressed the vacuum valve would decrease the vacuum to the actuator and the spring pressure in the actuator would move the vanes to the closed position, increasing boost. When boost rose, the pressure against the boost spring would push the vanes back open. You would likely need to be able to change the actuator spring in order to dial in max boost. You would also very likely need to add a vacuum reservoir and check valve so that you don't lose both brake assist and vane control function. Get to it and report back.
Hmmm? I will got hunting for parts now! Thanks!