ITT: MS3 1.4.0+ and Closed Loop EBC
#161
Tweaking Enginerd
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again, sorry but this is not how it works. A standard 4-port configuration regulates the pressure on both sides of the diaphram with a single control variable. A single increment in the control variable results in ~roughly~ a 2x difference in the pressure differential across the diaphram when compared either of the other configurations. For the configuration referenced you are regulating the pressure differential across the diaphram relative to the engine PR. For the other single hose hookup configuration you are regulating vs atmo. The science behind it is proven in math, but I am not going to post that here.
#163
From the link you posted the setup you described has port 1 to the open side of the wastegate, port 3 to the close side, and port 2 to boost. When de-energized port 1 and 2 connect and port 3 has no flow, when energized port 3 and 2 connect and port 1 has no flow. At steady state boost with the solenoid switching back and forth (aka wgdc is not 0% or 100%) the pressure on both sides of the diaphragm will equalize, assuming for zero leakage. Based on the mac33 diagram. Now if your 3 port has the closed port actually vent then it works literally identical to the 4 port setup, where you connect port A to close, B to open, input to boost, and exhaust to a muffler. When de-energized input connects to port A, port B connects to exhaust, when energized input connects to port B and port A connects to exhaust, based on mac46 diagram.
I'm not arguing the math, I'm saying the physical connection doesnt work.
I'm not arguing the math, I'm saying the physical connection doesnt work.
#164
Tweaking Enginerd
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open = open IWG flapper, decrease boost
close = close IWG flapper, more boost
The Turbosmart reference is for an EWG, not an IWG, obviously you need the pressure source connected to "open" and a NC port on the solenoid. You need the corresponding NC port on the soleniod (which is VTA when not energized) connected to the "close" side of the actuator. When the solenoid is energized, the "close" side is pressurized by approximately the dutycycle% / 100. So if the dutycycle is 50%, the "close" is pressurized to 50% of the pressure source. The WG spring opens at lets say 7psi. So when the differential is 7psi, the WG opens. The pressure differential will be 7psi when the "open" is greater than the "close" by 7psi, the "close" is 50% of the "open". This happens at 14psi. 14psi - 0.5*14psi = 7psi. This can be done with either a 4-port or 3-port style solenoid. When using a 4-port style, I prefer to block the port 1 NO port.
that sure seems like jibberish.
close = close IWG flapper, more boost
The Turbosmart reference is for an EWG, not an IWG, obviously you need the pressure source connected to "open" and a NC port on the solenoid. You need the corresponding NC port on the soleniod (which is VTA when not energized) connected to the "close" side of the actuator. When the solenoid is energized, the "close" side is pressurized by approximately the dutycycle% / 100. So if the dutycycle is 50%, the "close" is pressurized to 50% of the pressure source. The WG spring opens at lets say 7psi. So when the differential is 7psi, the WG opens. The pressure differential will be 7psi when the "open" is greater than the "close" by 7psi, the "close" is 50% of the "open". This happens at 14psi. 14psi - 0.5*14psi = 7psi. This can be done with either a 4-port or 3-port style solenoid. When using a 4-port style, I prefer to block the port 1 NO port.
that sure seems like jibberish.
#165
Thats not right. If you block the exhaust port of a 4 port and put it at 50% duty cycle and 14psi of constant boost both sides of a diaphragm will quickly achieve steady state of 14psi assuming no leakage. The same as if you hook up a 3 port the same way. It only works in real life because there is leakage but making your pneumatic system work based on leakage is the same as having a suspension that can only actuate due to bearing flex and it would be bound if you replaced all the joints with sphericals.
#166
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With a 4 port solenoid you simply block one of the ports and it works like a 3 port, where 1 port (A) is routed to one of the other two (B) when energized, and it is routed to the 3rd when not energized (C). The last port (D) is blocked, which causes the (C) port to be blocked when energized, and the (B) port to be blocked when not energized. A "4 port" setup is one in which one wg volume is connected to a dedicated port, the other wg volume is connected to a dedicated port, the pressure source and vent are also both dedicated ports.
in the referenced design, the "open" is always connected to the pressure source. The "close" is VTA when not energized, pressure source when energized. This is a fail safe setup, if the solenoid fails, you get WG spring boost.
I feel like we have a miscommunication here.
in the referenced design, the "open" is always connected to the pressure source. The "close" is VTA when not energized, pressure source when energized. This is a fail safe setup, if the solenoid fails, you get WG spring boost.
I feel like we have a miscommunication here.
#169
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well there you go, we are talking about different configurations. Yes, hooking up as shown on 11 will function as you describe. 10 works the way I ha e been describing. I can't think of a single application where the configuration on page 11 would be desirable.
#175
Good info here. They mention this about 4-port EBC:
"Boost control resolution can be terrible. This means that just changing the duty cycle on the wastegate just 1% might swing boost by as much as 3-4 psi."
I'm seeing this exact phenomenon.
So for the 3-port configuration. I've got their 7psi spring. So I'll be able to get 14-18psi. But I want to be able to get into the upper 20s. So I need to change my base spring pressure to at least 11 (or more) to achieve my upper 20s.
"Boost control resolution can be terrible. This means that just changing the duty cycle on the wastegate just 1% might swing boost by as much as 3-4 psi."
I'm seeing this exact phenomenon.
So for the 3-port configuration. I've got their 7psi spring. So I'll be able to get 14-18psi. But I want to be able to get into the upper 20s. So I need to change my base spring pressure to at least 11 (or more) to achieve my upper 20s.