i read a lot of posts and threads about 3 port solenoids, but i have some difficulties understanding some things.

First of all, the original Evo boost control system is based on the bleed type. So a line goes from turbo to wastegate throw a T and there is put the original solenoid. If you open the solenoid more, you bleed more air and make more pressure. Until here everything is ok.


But when you want to install a 3 port solenoid, there is a communication port, a NO (normally open) port and a NC (normally closed) port on the solenoid. That means, when there is no current on the solenoid, the COM and NO are connected, and then you put current the COM and NC are conected.

The 2 port OEM solenoid has the NC port to the T and the COM to atmosphere.

I don't have any GM solenoids, so i don't know from the pictures from the internet which port is which. I have only Perrin Solenoid and Greddy Solenoid.

I tried different ways of controlling the boost using this, but none of the ways seemed to be good.

1. I put the solenoid instead of the T, but i was over spiking bad. So i assumed that is not the best way.

2. I kept the original T and put the solenoid in every way but always was something that made me think that is no good.

So please explain one and for all for do you put your solenoids and how do you control them to make the desired boost and not overspiking? Do you use also pills in the lines? Do you use direct boost control of mrfred?

And something else, why in the Max WGDC is 139% max value??? Is this value equal with fully open?


Please be patience and explain me (try not to give me links from this forum because i read all the threads and i will just circle around) this because there are a lot of different threats on this forum and i cannot make a clear image.

 

3 ports are (for GM solenoid):

On one side there's one nipple - that's intake. (pressure from turbo)

On the other side 2 nipples - both for bleeding air. One will go to WGA, one will be bled to atmosphere or intake.
At 100% one of them is fully open and the other one is fully closed. At 0% it's reversed. The one that's open at 100% should be vented. Although technically it doesn't matter which one you use to bleed and which one is hooked up to WGA. But for the sake of having highest boost when your BWDC table says 100% - it should be vented. If you reverse them, you'll get the highest boost with 0%, that's all.

On a GM unit the nipple with metal clamps around it is vented at 100%. So vent it to atmosphere (or intake). No T's needed.

Hope this helps.


Also i wouldn't worry about 139 or 127.5 or whatever being the highest value you can put in the table. Use 100% as highest.

 

Ok so you put the 3 port instead of the t. And do you keep any of the OEM pills? I have tried that, i put the solenoid this way, i kept the OEM turbo pill but i was spiking like hell. If i was setting the WGDC for 1.7bar, at quick throttle i was making 2.x bar (out of the gauge). So my problem in that case was the setting in the EcuFlash or the way i set the solenoid and lines?

What king of settings do you have at turbo with the solenoid instead of the T?

 

Use new hose. Do not use existing hose, pills or T piece.

Connect the COM port (Perrin Port 1) to the turbo actuator.
Connect the NO (Perrin port 3) to the nipple on the turbo outlet.

Set your target load in Ecuflash
Make Error Correction % all 0
Start with WGDC at 30%
Raise duty cycle until you get to you target boost and have a smooth boost curve

Read the following for further information:
https://www.evolutionm.net/forums/sh...d.php?t=288408

 

Pills need to be removed. All you need is 2 pillless vacuum lines. One to turbo, one to WGA. That's it.

 

There is a great write-up on how to use the GM 3port wtih the ECU. It is not a drop in replacement for the stock solenoid. It has to be tuned.

If your duty is 139% then it's maxed out for the stock solenoid. The GM 3 port probably only needs about 50% duty cycle.

As far as how to hook it up, remove your stock hoses and keep them incase you return your vehicle to stock. Purchase vacuum hose and connect as follows.

COM port Turbo nipple
NO port wastegate actuator
FOAM port back to intake pipe

 

I believe Sabin is using the Greddy 3 port that may be the same thing...not sure never seen one.

 

It must be the same thing, but i had a problem because i never know which port is which in the GM solenoid. And the vacuum lines (the size) is a very important issue.

With 3.5 mm hoses all around, and the solenoid instead of the T i was overboosting bad.

Aaron, now i realize that i don't know what was in the rally car exactly because lots of peoples put their noses inside. So i'm like in the square one.

Today i tried a Perrin Electronic Solenoid. It is very very nice, big and well made. I put it in a Evo IX and it didn't worked at all. No response. I put the WGDC table at 100% and 0% all i got was mechanical pressure (0.8 atm). So what can be the problem. I didn't put any resistor n the harness.

If i want to buy a GM here in Romania it will cost me 210$ and a Perrin 100$.

So my conclusion now is that everyone is putting the solenoid instead of the T with new hoses and no restrictor pills and control this. I will try it.

 

If the Perrin didn't make any boost its DOA or the lines are hooked up incorrectly.

You can also use a AEM 3port, which is a MAC valve.

 

to be sure which port is which i breath throw every port. And when it has no power i see which ports are interconnected and then i put it on a 12v and see again which port are interconnected.

With the perrin i tried to use exactly like the original solenoid. I let on the car the turbo restrictor, the T and put the solenoid instead of the original. I connected the T (bleed line) with the NC port of the solenoid. So when no current to the solenoid the bleed line was closed, when energized the solenoid should vent to atmosphere. But no boost.

 

That is why. No T or pills are used with a 3port. Straight vac lines with no pills. 1 to pressure source, one to wastegate actuator and one to air or back into the intake system.

 

For the perrin 3 port solenoid:

Port 1: Vac line to the wastegate actuator

Port 2: Vac line to the stock accordian intake nipple (on the bottom)

Port 3: Vac line to pressure source (like the black compressor outlet pipe nipple)

DO NOT use any of the OEM stock boost lines for this. Use straight vac lines with no pills.

 

Ok i will try this tomorow.

And how do you set the desired load table in this case? if you want to go around 1.7 bar


Tell me stupid, i don't mind! i just wanna learn some stuffs.

 

I've ran the GM boost solenoid for a while now, it works great.

 

Set the boost with the Wastegate tables, then set the BDEL for error correction capibilities. Do search in this forum, there are a couple how-to's.