Notices
Evo Engine / Turbo / Drivetrain Everything from engine management to the best clutch and flywheel.

Not building boost past 13-15 psi

Thread Tools
 
Search this Thread
 
Old Oct 7, 2014, 05:39 PM
  #1  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
Not building boost past 13-15 psi

Ok please bear with me as I have searched, but I have found nothing that relates to my issue, as I don't have an OEM setup.
6466 Tial MVR 44 wastegate(set to 21 psi with springs), and a hallman mbc (ceramic ball, heavy spring) External waste dump
I cannot build boost past 9 psi doing a 3rd gear pull, and not past 14 psi in 5th gear.

I have done boost leak which was awesome, no leaks up to 30 psi. This issue was there BEFORE I installed the mbc, SAME ISSUE now as well.

Wastegate line goes from compressor nipple to mbc, then mbc to wastgate. Before I installed the mbc it was straight nipple to wastegate. I have manually cycled the wastegate with an air compressor, and it works fine no leaks, goes in and out smooth. I am truly out of ideas, during a pull it builds and the car wants to go, but I loose power.
I have also made sure that the correct ports are open on the WG and the ones that need to be closed, are indeed closed.

Now I'm pretty sure I would hear my dump because its just a straight pipe to the ground, but I'm sure I have not heard the wastgate dump yet on this car. I am literally loosing my mind trying to figure out why I can't boost past 25 psi or even 30. I have turned the mbc all the way down, no change. Is it possible that I have a severe case of boost creep? And if so what can I do to fix it? The only thing I haven't tried is getting the wastegate source from the manifold, which is a pain, as I have no free ports.
Oh E85 10.5:1 2.4 LR motor.

Last edited by galantman03; Oct 8, 2014 at 04:39 PM. Reason: added more info
Old Oct 8, 2014, 09:24 AM
  #2  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
I would appreciate any help guys thanks!
Old Oct 8, 2014, 04:38 PM
  #3  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
Updated up top
Old Oct 9, 2014, 08:34 PM
  #4  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
Old Oct 10, 2014, 12:04 PM
  #5  
Newbie
iTrader: (1)
 
dsmaniac's Avatar
 
Join Date: Jun 2014
Location: Washington, DC
Posts: 33
Likes: 0
Received 1 Like on 1 Post
Well, now that you're offering beer

Can you tell me which line you have going to the Tial, top or bottom port? Picture would be nice to to troubleshoot this issue. Also, what size exhaust housing do you have, T3, twin scroll T4...?
Old Oct 10, 2014, 12:06 PM
  #6  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
I knew the beer would get someone lol
The boost source line goes to the bottom port on the Tial, and the top ports are VTA I'm sorry I thought I put that, its VBAND .83 A/R
Old Oct 10, 2014, 12:13 PM
  #7  
Newbie
iTrader: (1)
 
dsmaniac's Avatar
 
Join Date: Jun 2014
Location: Washington, DC
Posts: 33
Likes: 0
Received 1 Like on 1 Post
How does it pull at 15lbs of boost? I might thing you have too much back pressure which is causing the wastegate to open. It has been happening to me with this lame synapse 50mm wastegate. I would suggest running it like this to see if you have any good results.
Attached Thumbnails Not building boost past 13-15 psi-wgdiag1.jpg  
Old Oct 10, 2014, 12:22 PM
  #8  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
I don't understand how I could have so much back pressure when I'm running 3 inch exhaust, I mean I do have a cat, but its a high flow cat. and its deff not clogged after 1500 miles. Can you explain to me on running that setup how it will function? Because right now its not making any sense in my head.
Old Oct 10, 2014, 12:27 PM
  #9  
Newbie
iTrader: (1)
 
dsmaniac's Avatar
 
Join Date: Jun 2014
Location: Washington, DC
Posts: 33
Likes: 0
Received 1 Like on 1 Post
Not back pressure in your turbo-back exhaust but in your manifold, pre-turbo. If there is too much back-pressure in the manifold, it will push open the wastegate.
Old Oct 10, 2014, 12:35 PM
  #10  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
So based on the pic that you posted that will keep the gate closed?
Old Oct 10, 2014, 12:48 PM
  #11  
Newbie
iTrader: (1)
 
dsmaniac's Avatar
 
Join Date: Jun 2014
Location: Washington, DC
Posts: 33
Likes: 0
Received 1 Like on 1 Post
So how this configuration will work is, the bottom port will be tee'd in with your compressor housing and the bottom port of the wastegate. This will hold the gate open by applying pressure under the diaphragm. If your exhaust back-pressure is higher than your intake pressure then you are at risk of the gate opening. The other port, which is perpendicular to the MBC will go directly to the top nipple. This will seal off the top of the diaphragm, not allowing it to be pushed open. The boost controller will control how much pressure gets bled off the top of the diaphragm. open diaphragm = open gate.

BTW, is this a brand new wastegate or something you picked up used?

Springs have changed color over the years so make sure you verify you have the correct spring.
http://tialsport.com/documents/MVRspc.png
Old Oct 10, 2014, 01:04 PM
  #12  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
Everything was bought brand new.
Is this what your talking about? (see attachment)
Attached Thumbnails Not building boost past 13-15 psi-boost.png  
Old Oct 10, 2014, 01:08 PM
  #13  
Newbie
iTrader: (1)
 
dsmaniac's Avatar
 
Join Date: Jun 2014
Location: Washington, DC
Posts: 33
Likes: 0
Received 1 Like on 1 Post
Originally Posted by galantman03
Everything was bought brand new.
Is this what your talking about? (see attachment)
You got it!
Old Oct 10, 2014, 01:10 PM
  #14  
Evolving Member
Thread Starter
iTrader: (7)
 
galantman03's Avatar
 
Join Date: Sep 2010
Location: WEST SIDE, SD
Posts: 301
Likes: 0
Received 0 Likes on 0 Posts
Ok then one last question. Does the wastegate still function what it is designed for when it is installed this way? AKA when does it divert gasses?
Old Oct 10, 2014, 01:37 PM
  #15  
Newbie
iTrader: (1)
 
dsmaniac's Avatar
 
Join Date: Jun 2014
Location: Washington, DC
Posts: 33
Likes: 0
Received 1 Like on 1 Post
Yes, you just just start with the MBC all the way out and work your way in. There is a hole in the MBC the allows air to bleed off but the farther MBC is screwed down the less air gets out. Less air that gets out, the higher the boost goes.


Quick Reply: Not building boost past 13-15 psi



All times are GMT -7. The time now is 12:58 PM.