how do i install this 3 port mac valve for boost control?

[r32-25t]

Well you need something to control the mac valve 

[robbo_rb180]

The haltech controls it once its installed and a 2d or 3d duty cycle map controls its output, can be setup as open or closed loop.
I would recommend not installing it atm and wait until the haltech is installed with the mac valve installed at same time and then tuned. 

a potentiometer can installed wired to the ecu to control levels of boost via voltage. Another way is a 3d table with rpm vs tps or rpm vs ethanol or wheel speed vs rpm, even one of the mentioned with another overlay of the combinations.

End of the day the haltech needs to be installed with the mac valve to make use of it.

Edited October 16, 2022 by robbo_rb180
Added heaps of complicated information

[Duncan]

Those boost controller units are for use with an ECU that can't do boost control, like standard or power FC. Haltech will look after that in your case, once it is in and tuned

[kevboost7]

appreciate it guys

[joshuaho96]

4 hours ago, kevboost7 said:

appreciate it guys

If you want a knob or a switch/button/etc to adjust the boost any standalone ECU can do that too. 

[kevboost7]

On 10/2/2022 at 8:19 PM, joshuaho96 said:

Didn't you post this question on Reddit already? If not here's my answer again:

https://www.gtrusablog.com/2013/02/rb26dett-vacuum-and-wastegate-diagram.html

Port 1 is the blue line. Port 2 is the green line. Port 3 is also the green line. The key point is that you will have to modify the vacuum line for port 3. Instead of tying port 2 and 3 together you cap the vacuum line on the combo coolant/vacuum pipe and the line on the plenum goes directly to the valve. Port 2 has unchanged routing.

As others have said don't do this until you get the new ECU installed and set up properly. Only do it once you're ready to set up boost control to reduce the number of variables.

Hey @joshuaho96 i got my car tuned last weekend, and we installed the 3 port mac. The tuner turned up the boost on the computer, but it wasn't actually boosting any higher... i'm re-reading your instructions and they are confusing. 

"Port 1 is the blue line. Port 2 is the green line. Port 3 is also the green line. The key point is that you will have to modify the vacuum line for port 3. Instead of tying port 2 and 3 together you cap the vacuum line on the combo coolant/vacuum pipe and the line on the plenum goes directly to the valve. Port 2 has unchanged routing."

What you said in quotation above, does not align with the diagram with the twin turbos.

According to the diagram, port 2 is the wastegate and would be the green line. 

 

[joshuaho96]

56 minutes ago, kevboost7 said:

Hey @joshuaho96 i got my car tuned last weekend, and we installed the 3 port mac. The tuner turned up the boost on the computer, but it wasn't actually boosting any higher... i'm re-reading your instructions and they are confusing. 

"Port 1 is the blue line. Port 2 is the green line. Port 3 is also the green line. The key point is that you will have to modify the vacuum line for port 3. Instead of tying port 2 and 3 together you cap the vacuum line on the combo coolant/vacuum pipe and the line on the plenum goes directly to the valve. Port 2 has unchanged routing."

What you said in quotation above, does not align with the diagram with the twin turbos.

According to the diagram, port 2 is the wastegate and would be the green line. 

 

Not sure I can make it any clearer than this. Notice how one of the hoses has a restrictor from the factory. Either cut it out, work it out with lubricant, or make a new length of hose without it.

[kevboost7]

1 hour ago, joshuaho96 said:

Not sure I can make it any clearer than this. Notice how one of the hoses has a restrictor from the factory. Either cut it out, work it out with lubricant, or make a new length of hose without it.

are you in the states? i wish i could talk to you on the phone. Not sure if you're up for that. My number is 703-626-8787

[GTSBoy]

1 hour ago, kevboost7 said:

are you in the states? i wish i could talk to you on the phone. Not sure if you're up for that. My number is

Dude, this is what PM is for, so your phone number isn't stuck on the internet.

[Dose Pipe Sutututu]

@PranK can you please remove his number!

[GTSBoy]

Besides which, it is not important to know whether to hook port 1 up to the fuel tank, or the windscreen washer line. it is important to understand how the 3 port valve works. And then you can work out where to connect the ports all by yourself.

A 3 port solenoid valve has two states. Powered and non-powered.

In the at-rest, non-powered state, 2 of the ports are connected.

In the powered state, one of those ports is not connected to the 3rd port.

The one that is common to both those connections is called.....the common port. This one gets connected to the boost source.

The one that is connected to common when it is not powered gets connected to the wastegate actuator. This way, if the valve is doing nothing, you get wastegate spring base boost.

The one that is connected to common when powered is the vent. Vent to atmosphere or back to the post-AFM inlet as you see fit.

You can work out which connections occur when by just trying to blow through the ports powered and unpowered. Helpfully, the MAC valve also usually has a little diagram on the side that shows exactly how it works.

[kevboost7]

What is confusing me is the green line going to the wastegates that is also connected to the plenum. Why can't i just replace the factory boost selonoid with a 3 port mac? Why do i have to cap off the factory dual vacuum/coolant pipe and use the line from the plenum?

[GTSBoy]

2 hours ago, GTSBoy said:

In the powered state, one of those ports is not connected to the 3rd port.

Erk. I just realised a typo. "not" in the above should be "now".

[GTSBoy]

1 hour ago, kevboost7 said:

Why can't i just replace the factory boost selonoid with a 3 port mac?

Because the factory boost solenoid doesn't work in the same manner that the 3 port valve does.

Riddle me this. How many ports does the factory solenoid have?

Riddle me also this. How is the factory solenoid used by the ECU? Is it just switched on and off, to provide a two state boost control system? Or is it pulse width modulated like a proper boost control system (ie, the sort that uses a 3 port solenoid)? Hot tip. It's not the second of those.

And so, you need to trash the factory plumbing and replace it with plumbing that will work according to the new system.

1 hour ago, kevboost7 said:

Why do i have to cap off the factory dual vacuum/coolant pipe and use the line from the plenum?

See above.

[joshuaho96]

6 hours ago, kevboost7 said:

What is confusing me is the green line going to the wastegates that is also connected to the plenum. Why can't i just replace the factory boost selonoid with a 3 port mac? Why do i have to cap off the factory dual vacuum/coolant pipe and use the line from the plenum?

Factory solenoid is 2 ports only as others have said. To make a two port solenoid work you must tie the wastegate line to the plenum (boost source). That way when the solenoid isn't working the engine just makes wastegate boost. Then when the solenoid activates it vents to atmosphere (blue line). When you vent to atmosphere the problem with a 2 port solenoid is two-fold. First, it's a boost leak which is annoying. Second, you really want the pressure experienced by the wastegate to be as low as possible. With a 2 port solenoid the wastegate line will always see a pressure higher than atmospheric because the turbo's boost is bleeding both to atmosphere and into the wastegate line.

The 3 port splits the two states. Either you are sending boost pressure to the wastegate line (solenoid is off) or you are venting the wastegate line to atmosphere (solenoid is on).

Edited October 22, 2023 by joshuaho96

[kevboost7]

10 hours ago, joshuaho96 said:

Factory solenoid is 2 ports only as others have said. To make a two port solenoid work you must tie the wastegate line to the plenum (boost source). That way when the solenoid isn't working the engine just makes wastegate boost. Then when the solenoid activates it vents to atmosphere (blue line). When you vent to atmosphere the problem with a 2 port solenoid is two-fold. First, it's a boost leak which is annoying. Second, you really want the pressure experienced by the wastegate to be as low as possible. With a 2 port solenoid the wastegate line will always see a pressure higher than atmospheric because the turbo's boost is bleeding both to atmosphere and into the wastegate line.

The 3 port splits the two states. Either you are sending boost pressure to the wastegate line (solenoid is off) or you are venting the wastegate line to atmosphere (solenoid is on).

What happens if the factory solenoid is not activated and it is not tied to the plenum? Wont it just bleed the air back? And when you say blue line, isn't the blue line the turbo pressure?

[kevboost7]

Right now, this is how everything is connected in my car. According to the theory, everything should be working.. its just that other green line going to the plenum that is confusing me. 

[kevboost7]

According to your explanation @joshuaho96 this is how it should be connected right? What i don't understand is that if i route all the lines like this... how is the plenum equal to the wastegate line? I thought port 2 on the MAC valve should be port the waste gate line?

I really appreciate you guys helping me look at these diagrams. 

[joshuaho96]

26 minutes ago, kevboost7 said:

According to your explanation @joshuaho96 this is how it should be connected right? What i don't understand is that if i route all the lines like this... how is the plenum equal to the wastegate line? I thought port 2 on the MAC valve should be port the waste gate line?

I really appreciate you guys helping me look at these diagrams. 

The blue line is not boost. It is a vent to atmosphere.

The green line going to the plenum is the boost source.

My original diagram already shows what you need to cap. You only cap one pipe on the engine and then re-route the hose to go to the boost solenoid directly. The rest is unchanged. 

[kevboost7]

30 minutes ago, joshuaho96 said:

The blue line is not boost. It is a vent to atmosphere.

The green line going to the plenum is the boost source.

My original diagram already shows what you need to cap. You only cap one pipe on the engine and then re-route the hose to go to the boost solenoid directly. The rest is unchanged. 

@joshuaho96 I'm sorry josh , i dont know if i'm dumb or missing something here, but your original diagram makes no sense with my configuration. I have internal waste gates.

This is what you said: "Port 1 is the blue line. Port 2 is the green line. Port 3 is also the green line. The key point is that you will have to modify the vacuum line for port 3. Instead of tying port 2 and 3 together you cap the vacuum line on the combo coolant/vacuum pipe and the line on the plenum goes directly to the valve. Port 2 has unchanged routing." 

based on that description of what you said above^^ this is what the connections should look like below:

is that what you are suggesting? Port 1 on the Mac valve (vent to atmosphere) should go back to the turbo pressure?