MEGAsquirt A place to collectively sort out this megasquirt gizmo

ITT: MS3 1.4.0+ and Closed Loop EBC

Thread Tools
 
Search this Thread
 
Old 12-05-2018, 09:35 PM
  #161  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

Originally Posted by Leafy
If you use all the ports from the 3 port and it vents then its actually a 4 port that has an exhaust port that you cant connect to and its exactly the same as the 4 port setup.
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.
Ted75zcar is online now  
Old 12-05-2018, 09:41 PM
  #162  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

This is just 1 page of several on the derivations for how these things work.


Ted75zcar is online now  
Old 12-05-2018, 09:49 PM
  #163  
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,479
Total Cats: 104
Default

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.
Leafy is offline  
Old 12-05-2018, 10:13 PM
  #164  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

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.
Ted75zcar is online now  
Old 12-05-2018, 10:22 PM
  #165  
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,479
Total Cats: 104
Default

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.
Leafy is offline  
Old 12-05-2018, 10:44 PM
  #166  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

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.
Ted75zcar is online now  
Old 12-05-2018, 11:21 PM
  #167  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

You are looking at the diagram on page 10 right?

solenoid connects 2 and 3 when not energized, 2 and 1 when energized.
Ted75zcar is online now  
Old 12-06-2018, 06:26 AM
  #168  
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,479
Total Cats: 104
Default

Originally Posted by Ted75zcar
You are looking at the diagram on page 10 right?

solenoid connects 2 and 3 when not energized, 2 and 1 when energized.
Bottom of page 11.
Leafy is offline  
Old 12-06-2018, 08:08 AM
  #169  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

Originally Posted by Leafy
Bottom of page 11.
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.
Ted75zcar is online now  
Old 12-06-2018, 09:39 AM
  #170  
Retired Mech Design Engr
iTrader: (3)
 
DNMakinson's Avatar
 
Join Date: Jan 2013
Location: Seneca, SC
Posts: 5,009
Total Cats: 857
Default

A picture is worth 1000 words. The wrong picture is worth -1000 words.
DNMakinson is offline  
Old 12-06-2018, 09:50 AM
  #171  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

Originally Posted by DNMakinson
A picture is worth 1000 words. The wrong picture is worth -1000 words.
well said sir.
Ted75zcar is online now  
Old 12-06-2018, 09:53 AM
  #172  
Junior Member
 
Mudflap's Avatar
 
Join Date: May 2017
Location: Louisville, Co
Posts: 466
Total Cats: 86
Default

Good lord above, OK, so now how does that apply to an IWG? Just swap the ports around on the EWG diagram on page 10? Can I now turn my brain back on after it shutting down so abruptly last night?
Mudflap is offline  
Old 12-06-2018, 09:54 AM
  #173  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

Originally Posted by Mudflap
Good lord above, OK, so now how does that apply to an IWG? Just swap the ports around on the EWG diagram on page 10? Can I now turn my brain back on after it shutting down so abruptly last night?
it looks like they provide a diagram for the IWG that correlates to the page 10 diagram in the installation instructions for the BW 2 port IWG.

edit: last configuration shown here
Ted75zcar is online now  
Old 12-06-2018, 10:16 AM
  #174  
Junior Member
 
Mudflap's Avatar
 
Join Date: May 2017
Location: Louisville, Co
Posts: 466
Total Cats: 86
Default

Exactly, OK, now I'll engage thrusters on full. Punch it Chewy, etc.

I'm gonna sell all this and buy a camper..
Mudflap is offline  
Old 12-06-2018, 05:57 PM
  #175  
Junior Member
 
Mudflap's Avatar
 
Join Date: May 2017
Location: Louisville, Co
Posts: 466
Total Cats: 86
Default

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.
Mudflap is offline  
Old 12-06-2018, 06:03 PM
  #176  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

I have a spare 11 from TS if you want to try it out.
Ted75zcar is online now  
Old 12-06-2018, 06:15 PM
  #177  
Junior Member
 
Mudflap's Avatar
 
Join Date: May 2017
Location: Louisville, Co
Posts: 466
Total Cats: 86
Default

I do, I'll bug you about it later. You around this weekend?

Believe it or not, I through away the inner spring. I had it sitting on my desk for long enough that I forgot what the heck it was for... so I tossed it. $27.00 for a replacement.
Mudflap is offline  
Old 12-06-2018, 06:15 PM
  #178  
Tweaking Enginerd
iTrader: (2)
 
Ted75zcar's Avatar
 
Join Date: Mar 2013
Location: Boulder, CO
Posts: 1,775
Total Cats: 358
Default

Yep, and yep, they are proud of their springs.
Ted75zcar is online now  
Old 05-15-2019, 05:47 PM
  #179  
Junior Member
 
Tran's Avatar
 
Join Date: Jul 2017
Location: Sussex, England
Posts: 223
Total Cats: 46
Default

A bit of a silly question, but I've just upgraded to 1.5.1 and was expecting to be logging EBC P, I, D channels, yet my logs do not contain them and I can't find a checkbox to activate them. Am I missing something?
Tran is offline  
Old 05-15-2019, 06:38 PM
  #180  
Junior Member
 
Tran's Avatar
 
Join Date: Jul 2017
Location: Sussex, England
Posts: 223
Total Cats: 46
Default

Originally Posted by Tran
A bit of a silly question, but I've just upgraded to 1.5.1 and was expecting to be logging EBC P, I, D channels, yet my logs do not contain them and I can't find a checkbox to activate them. Am I missing something?
I think I've found it. Need to activate "Internal_log_fields" logging in project properties.
Tran is offline  


Quick Reply: ITT: MS3 1.4.0+ and Closed Loop EBC



All times are GMT -4. The time now is 11:57 AM.