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

[GTSBoy]

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.

[kevboost7]

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:


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)

   

 

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.

 

[kevboost7]

Is it possible that there is a leak somewhere? or if my turbos are gone? or if my wastegates are stuck?

[r32-25t]

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

[kevboost7]

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?

[r32-25t]

It’s what pretty much everyone does and is also what everyone has been telling you to do. most people run a new set of wires from the ecu 

[joshuaho96]

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)

   

 

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.

 

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:

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. 

[GTSBoy]

29 minutes ago, joshuaho96 said:

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.

Outlet pressure regulator.

[joshuaho96]

4 hours ago, GTSBoy said:

Outlet pressure regulator.

This is the correct way yes. 

[kevboost7]

Just wanted to update everyone. I finally got around to working on the car this year and I did a boost leak test. It seems like i was hooking up the 3 port mac-valve correctly, but there is a massive leak on the rear turbo's wastegate actuator. Where the seam comes together. 

Edited June 8, 2024 by kevboost7

[GTSBoy]

Excellent

/Mr Burns

[Duncan]

On 09/06/2024 at 8:53 AM, kevboost7 said:

Just wanted to update everyone. I finally got around to working on the car this year and I did a boost leak test. It seems like i was hooking up the 3 port mac-valve correctly, but there is a massive leak on the rear turbo's wastegate actuator. Where the seam comes together. 

Thanks for updating the outcome; while anywhere in the system could leak, I hadn't heard of a wastegate actuator doing so before, can add that to the list of potentials for next time

[joshuaho96]

On 6/8/2024 at 3:53 PM, kevboost7 said:

Just wanted to update everyone. I finally got around to working on the car this year and I did a boost leak test. It seems like i was hooking up the 3 port mac-valve correctly, but there is a massive leak on the rear turbo's wastegate actuator. Where the seam comes together. 

Interesting, I've never seen a failure like that before but with the age of these cars and the general questionable-ness of all kinds of parts these days you can't rule anything out I suppose. Boost leak testing the boost control system would've revealed this though.

[kevboost7]

Hey update! I took the car out for a spin yesterday and oh my god, this feels like a different car! i think i finally experienced what more than 8psi of boost felt like. I had the duty cycle on the selnoid set to 50% and it was boositng to close to 22psi before the cut-off. I got to experience 1 second of pure bliss between 5000-8000rpms in each gear, until i hit 5th gear. But i will say, it is pretty laggy. like 1000-4000k has no action. Then 5k and beyond is just hold on to your seat kinda experience. 

before when i was running 8psi of boost, even though the car was objectively slower, it felt like, i could stay in the gear longer and really enjoy all 8000rpms. Now its more like, 1-4k, takes forever, then 5k (boost hits) and within miliseconds, its time for me to shift again. 

[Kinkstaah]

Make sure you tune it. And by "Sure" I mean that if you haven't, you may only have milliseconds before your engine turns into many large, loud pieces, smashed all over the road.

One does not just change boost from 8psi to 22psi without having tuning through all those load cells and that boost, unless of course the car was previously tuned at 22psi with the Haltech you have in there.

If that has already happened, cool.

If not, or IF YOU ARE UNSURE, then this is emergency, critical level vital.

[Dose Pipe Sutututu]

9 hours ago, kevboost7 said:

Now its more like, 1-4k, takes forever, then 5k (boost hits) and within miliseconds, its time for me to shift again. 

Imagine a single twin scroll turbo, boost hits at 4000 rpm and you'll make more power throughout the entire RPM range vs the twins.

Convert to a single turbo, twin scroll setup.

You're welcome.