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


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5 hours ago, joshuaho96 said:

This is what your setup is:

Port 1 - atmospheric vent
Port 2 - wastegate port
Port 3 - Pre-throttle boost source

Compared against this diagram:


So the vacuum line setup actually seems ok to me?

I'm not convinced.

Cameras can be put in places that heads cannot go. Better video required.

Or, just compare your known routing of hoses to the actual drawings of all this stuff from the manual. To me, it looks like you have 2 of your hoses routed to the plenum.

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10 hours ago, joshuaho96 said:

This is what your setup is:

Port 1 - atmospheric vent
Port 2 - wastegate port
Port 3 - Pre-throttle boost source

Compared against this diagram:
image.thumb.png.d63aa5459ec69ad4ec358bc87469ea3f.png

So the vacuum line setup actually seems ok to me? You might need to use an air compressor or just blow through the hoses. When it's off it should connect port 3 to port 2. When it's on it should connect port 1 to port 2 instead. Set it to 90% duty cycle on the Haltech and see if that is actually happening. Don't run the engine when doing this experiment and remember to set the values back to something normal afterwards.

Put 14 psi into port 1 vacuum line and verify you can hear it venting into the intake piping before the turbos. It shouldn't hold pressure substantially.

If all the function tests check out set a boost fuel cut for something very conservative like 2 psi over wastegate boost and set the solenoid duty cycle to 90%. If you still get stuck at wastegate boost then try just running with port 2 open to atmosphere with the same conservative boost cut. Before you actually set that boost cut the way I describe see if it works at 2 psi of boost for example. You don't want to find out after the fact whether the boost cut didn't work as intended. Make sure to set a large hysteresis as well in the fuel cut so you aren't bouncing off of it.

Not sure why everyone thinks i hooked it up wrong, but Josh is spot on with my vacuum line set-up.

The picture of my MAC valve shows the 2 red vacuum lines going to the water/coolant combo pipe and the black vacuum line is going to the last nipple under the plenum. (See below)

image.thumb.png.4da3a95a2c33a97d6d239eb56d4e21b4.png   image.thumb.png.56420a4f17ec2a121fcfb0ec043aca31.png

 

Josh i have a few questions:

1. You might need to use an air compressor or just blow through the hoses. When it's off it should connect port 3 to port

- Can i blow air with my mouth?

2. Put 14 psi into port 1 vacuum line and verify you can hear it venting into the intake piping before the turbos. It shouldn't hold pressure substantially.

- Why 14 PSI? I have a compressor, but im not sure if i can get it to those tolerances.

image.thumb.png.d09b944039ba3a9dc1cefbbf9c7119b0.png

 

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Just do it properly and put the valve on the other side of the engine bay, block the 2 red hoses off, take the boost source from where you are currently taking it under the plenum then using a t-piece connect port 2 to both of the waste gates and leave port 1 open

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6 minutes ago, r32-25t said:

Just do it properly and put the valve on the other side of the engine bay, block the 2 red hoses off, take the boost source from where you are currently taking it under the plenum then using a t-piece connect port 2 to both of the waste gates 

If i did that, how would i run the 2 electrical wires across the other side cleanly? Is that what you guys did?

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4 hours ago, kevboost7 said:

Not sure why everyone thinks i hooked it up wrong, but Josh is spot on with my vacuum line set-up.

The picture of my MAC valve shows the 2 red vacuum lines going to the water/coolant combo pipe and the black vacuum line is going to the last nipple under the plenum. (See below)

image.thumb.png.4da3a95a2c33a97d6d239eb56d4e21b4.png   image.thumb.png.56420a4f17ec2a121fcfb0ec043aca31.png

 

Josh i have a few questions:

1. You might need to use an air compressor or just blow through the hoses. When it's off it should connect port 3 to port

- Can i blow air with my mouth?

2. Put 14 psi into port 1 vacuum line and verify you can hear it venting into the intake piping before the turbos. It shouldn't hold pressure substantially.

- Why 14 PSI? I have a compressor, but im not sure if i can get it to those tolerances.

image.thumb.png.d09b944039ba3a9dc1cefbbf9c7119b0.png

 

The only thing I will say about your vacuum line routing is that you want to make sure you didn't accidentally go too high and use the vacuum chamber ports that go into the BOV and evap lines. I'm pretty sure you didn't because it appears to be angled correctly but you never know, the video is not crystal clear and I'm working off of some assumptions. Reference this picture to get an idea for what I'm talking about, you can see how the angled vacuum pipes attached to the coolant pipe are for the boost solenoid but there are two more ports for other things:

IMG_3612.thumb.jpeg.a9d2b7e10ea6e440213ce340fdf65b50.jpeg

You can probably just blow through the hoses with your mouth but it may not be enough flow to be sure that it's working one way or another. You don't need super precise pressure control, you just don't want to exceed 20 psi for example. So if your compressor has a tank just get it to 15 psi and then shut off the compressor entirely for the rest of the test. You only need to verify that the air is flowing through the solenoid the way it should be.

Everyone is telling you to run new lines for everything but personally if you have already verified the factory boost control worked before doing all this I still think using the OEM wiring + vacuum lines reduces the amount of unknowns you need to test. OEM is what works, the less you change the better IMO. 

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