I'm running dual 44mm MV-R wastegates and I currently have their vacuum lines routed in this manner:

-No Boost controller, just running off spring pressure so top ports are open
-Wastegate # 1's vacuum line is routed from a bottom port to Compressor housing
-Wastegate #2 is routed to a nipple I had welded on the hotside intercooler piping, right next to the silicone coupler.

Should I run both wastegates' vacuum lines off of the compressor housing instead and Tee it off? Or will this not matter based on how I have it currently setup?

I'm asking this because I had the car tuned recently, and the boost pressures dropped off almost 2 psi at the high RPMs... so I'm trying to figure out why.

Lastly, I'm using silicone hoses right now but I'd like to change over to -4AN stainless braided lines, or maybe even Nomex lines? For people who have done this, could you share what you did and what fittings you used?

Thanks

 

IMO, you want to have the boost source to be from the same port for both wastegates.

I currently run dual MV-R gates and used -4 stainless hardline for my vacuum lines. I also did the same for the coolant lines as well.

RE: boost dropping, what boost were you trying to achieve and what turbo? Have you checked for boost leaks?

 

Here's how I ran mines......twin 44mm tial mv-r gates at the bottom of the WG. I ran them all to a vacuum block which has a decent size port hole that makes things a whole lot cleaner.
BOV and each WG were ran indivdually to the vacuum block with their own -4 hoses (high press. rubber hoses). Hope this helps........

 

Nice!! i'm using a Vacuum block as well. But I ran my wastegates to a "T" and ran one line to the Block. I'm using normal old Vacuum line. But I'm probly going to take the whole line assembly to a shop and have them make some Stainless lines....for the wastegates to the Boost controller at least.


Using dual 50mm Synapse Wastegates
Routing goes like thisL:
Wastegate 1 to T fitting
Wastegate 2 to T fitting
T fitting to AEM Boost control Solenoid
Boost control Solenoid vacuum source is off the Turbine Compressor housing.

The Vacuum Block I have is a seperate looped system.
Starting off the UIM:

UIM port -6 fitting to -6 fitting on Vac Block
Vacuum Block feeds following
- ECU Map Sensor
- Boost Gauge
- Fuel Pressur Regulator
- BOV
- AEM Water/Meth Controller
- AN-6 fitting to Brake Booster.

 

Interesting setups! I like how the vacuum block acts like a hub and cleans everything up; however, it appears that the vacuum lines from your wastegates have to be ran longer to reach the block. Will this be of any detriment? I guess with Electronic Boost Controller setups, this probably isn't a big deal.

I'm only running off of my wastegates' springs with no boost controller. The pressure drop I'm experiencing at the top-end looks to be inherent of routing my vacuum lines to the turbo compressor/charge pipe, since that location gives the fastest readings. Routing the lines post-Intercooler should lag the wastegates and compensate for the boost pressure loss, but I don't think I want to route it that way right now.

I've also heard mixed ideas regarding Tee-ing the wastegates off from one port as it halves the flow and can supposedly contribute to overboosting?

 

The Waste-gates/Boost solenoid/compressor boost source, ...are all on their own closed system.
The Vacuum block/uim/BOV/FPR/brake booster/aem water meth are on a seperate loop. So they really don't see eachother.

I don't think it'll be of much detriment but don't take my word on it as i'm no expert. I'll just report back after my tune and let you know how it went. I don't think Tee-ing the wastegates off one port is any bit of a problem. I understand what your saying....but I'm not entirely sure it works that way. I was just informed from a respectable synapse gate user that this was the best/most consistent way that worked for his 2 50mm gates.

 

I like the set up I will be running similar to this