# 12V VR6 boost issues any help is appreciated



## Buddha92SLC (Jul 22, 2001)

12 valve VR turbo. Garret t4 turbo, Tial 38mm wastegate. C2 software. 

Car was running great. I hardly drive it anymore and I just hopped in to take it for spin the other day. Wouldn't boost past the spring pressure which was a small red spring (5psi). I had a Turbo XS dual stage manual boost controller so I thought maybe it went bad. I removed it and I installed a GReddy Profec B Spec 2 electronic boost controller. I was only able to double the wastegate spring pressure at 100% which was at around 9psi boost pressure.

So I ordered a big yellow spring 10 psi and installed it. I turned off the electronic boost controller and I'm still only seeing 5 psi! Now I'm scratching my head wondering what is going on. 

Any suggestions would be appreciated guys. Thanks in advance.
Zac


----------



## Buddha92SLC (Jul 22, 2001)

ttt


----------



## GinsterMan98 (May 19, 2008)

Sounds like your wastegate is stuck open or the fire ring is not installed. 

sent from a calculator using tapatalk.


----------



## Buddha92SLC (Jul 22, 2001)

The fire ring was installed correctly and the wastegate was closed fully when I changed the spring. Any other ideas?


----------



## masterqaz (Oct 5, 2007)

Pull the pressure reference line off and boost down the road. Keep an eye on it though cause it'll keep climbing.


----------



## Buddha92SLC (Jul 22, 2001)

Are you being serious or joking? That doesn't sound safe at all.


----------



## masterqaz (Oct 5, 2007)

Serious.... It's not safe which it why you don't go wot. Part throttle boost it and keep an eye on it. See if you can get it past your issue area of boost.


----------



## DieGTi (Jun 19, 2001)

Could be a torn diaphragm inside the wastegate from changing springs...


----------



## GinsterMan98 (May 19, 2008)

Agreed, it is turbo or wastegate related.

sent from a calculator using tapatalk.


----------



## V-dubbulyuh (Nov 13, 2005)

masterqaz said:


> Serious.... It's not safe which it why you don't go wot. Part throttle boost it and keep an eye on it. See if you can get it past your issue area of boost.



I had to do that just this past weekend. Car in question would not make more than 7 psi regardless of spring size. Cheap-azz turbo being used would not maintain requested boost level across the intercooler and into the intake manifold. Had to signal the wastegate from the intake manifold (instead of the compressor housing) as a temporary means of getting the desired boost level at the intake manifold. A turbo swap is in the near future of this person's car. Tried various wastegates, various wastegate springs, pressure tested the system to 30 psi... none proved related to the problem.


----------



## masterqaz (Oct 5, 2007)

V-dubbulyuh said:


> I had to do that just this past weekend. Car in question would not make more than 7 psi regardless of spring size. Cheap-azz turbo being used would not maintain requested boost level across the intercooler and into the intake manifold. Had to signal the wastegate from the intake manifold (instead of the compressor housing) as a temporary means of getting the desired boost level at the intake manifold. A turbo swap is in the near future of this person's car. Tried various wastegates, various wastegate springs, pressure tested the system to 30 psi... none proved related to the problem.


Running it from the intake gives part throttle boosting issues where the compressor will over spool and surge dump. Although wot will be ok. I ran mine like that for a long time but I finally got around to correcting it.


----------



## V-dubbulyuh (Nov 13, 2005)

masterqaz said:


> Running it from the intake gives part throttle boosting issues where the compressor will over spool and surge dump. Although wot will be ok. I ran mine like that for a long time but I finally got around to correcting it.


I know exactly the repercussions... it is being done as a tempo fix on a car that is not mine. 

As soon as the owner sources a better turbo I will be re-plumbing the signal from the compressor as it should be. From the intake manifold the wastegate will see vacuum which is not ideal but there are zero driveability issues so far (and is making the demanded boost that it was not before). I've been driving the car since Saturday ironing out other issues.


----------



## Buddha92SLC (Jul 22, 2001)

So it is either the wastegate or the turbo. What steps should I take to determine which of the two is the cause for the inability to reach the desired boost pressure?


----------



## V-dubbulyuh (Nov 13, 2005)

Did you cautiously run the car with the wastegate signal line removed as suggested? If so did you hit your desired boost? Have you tried alternative wastegates to see if there is something specific to your wastegate? Did you do a pressure test across the entire intercooler system?


----------



## masterqaz (Oct 5, 2007)

V-dubbulyuh said:


> I know exactly the repercussions... it is being done as a tempo fix on a car that is not mine.
> 
> As soon as the owner sources a better turbo I will be re-plumbing the signal from the compressor as it should be. From the intake manifold the wastegate will see vacuum which is not ideal but there are zero driveability issues so far (and is making the demanded boost that it was not before). I've been driving the car since Saturday ironing out other issues.


I was simply stating it for others benefit. Im sure a vrt master like yourself understood the repercussions.

On another note, theirs nothing like a 5 dollar boost leak tester, a 1 dollar spray bottle with some water and soap.


----------



## GinsterMan98 (May 19, 2008)

masterqaz said:


> I was simply stating it for others benefit. Im sure a vrt master like yourself understood the repercussions.
> 
> On another note, theirs nothing like a 5 dollar boost leak tester, a 1 dollar spray bottle with some water and soap.


Salty.


----------



## Buddha92SLC (Jul 22, 2001)

The signal line is the lower vacuum line on the wastegate... correct? Not the top one? 

I don't have another wastegate to swap out so that option is out. 

I don't have my new compressor plumbed yet so I can't pressure test the system right now. I'm 99% positive that I don't have a boost leak though, because it went up to 9psi with the electronic boost controller with the original 5psi spring. 

I'm leaning towards the idea that something is internally messed up with the wastegate like the diaphram being torn or something. I don't know what else could be wrong internally with the wg.

Here is a pic of my setup


----------



## DieGTi (Jun 19, 2001)

Possible to post some datalogs? Check for codes while you're in there.


----------



## 'dubber (Jun 15, 2004)

Wastegate signal line goes on the side port, and leave the top port open if just going off of spring pressure. Same setup with an mbc. A ball and spring Mbc will act as a check valve against the wg diaphragm seeing vacuum though. Also won't the car overboost with a torn diaphragm?


----------



## Buddha92SLC (Jul 22, 2001)

Ok, I pulled off both vacuum lines going to WG. Plugged both vacuum lines and kept both ports open on the WG. Took it for a ride and was only seeing 7-8psi. The WG has an 11psi spring. 

Would this mean that something is amiss inside the WG?


----------



## V-dubbulyuh (Nov 13, 2005)

Wastegate is probably stuck open (Ginster suggested this a while ago). Can you hear the wastegate exhausting when you hit 7 psi (is your wastegate open dump or recirc'd)? Seems like the wastegate is leaking though. 

On a side note, is the motor running through the RPM band just fine (or do you notice hesitation) and does the AFR look correct? I have seen a malfunctioning throttle body also cause what you are saying. There is not enough differential between intake/exhaust and the turbo essentially gets strangled to the point it produces minimal boost and only at very high RPM.


----------



## Buddha92SLC (Jul 22, 2001)

I believe the wastegate is opening. It is an open dump. No hesitation whatsoever through the rpm band. I'll pull off the wastegate again and take it apart to inspect it thoroughly and report back.


----------



## 20thAE JTI (Dec 21, 2008)

Could also be a bad diverter valve as well.


----------



## GinsterMan98 (May 19, 2008)

20thAE JTI said:


> Could also be a bad diverter valve as well.


 Previously tested and held 15 psi.


----------



## 'dubber (Jun 15, 2004)

Still could be getting stuck open while driving, but it seems like all the problems started with the big yellow spring, I'm not sure how much boost he expected out of the small spring and the ebc but it doubled it which is more than I would have expected. I'd probably check around the wastegate again.


----------



## Buddha92SLC (Jul 22, 2001)

Took off the wastegate again and took it apart totally. Everything looked great. Re-assembled and bench tested and it works fine. Now that I have the air compressor hooked up I was able to boost test the IC pipes. I have a massive boost leak at the silicone coupler right by the throttle body. I slid the piping back into the coupler and tightened the clamp. Hopefully this will resolve the issue. I'll report back after a test drive when I get the WG re-installed. 

There is also a small boost leak inbetweeen the GReddy BOV and the flange. Right at the gasket. I'm thinking of smearing some black permatex on each side of the gasket to seal that better. Any suggestions on what product to use there? Black silicone is all that I could think of, but not sure if that would work to hold back 20psi of boost pressure.


----------



## V-dubbulyuh (Nov 13, 2005)

Always the first step in any "lack of boost issues". 



V-dubbulyuh said:


> Did you do a pressure test across the entire intercooler system?





Buddha92SLC said:


> I have a massive boost leak at the silicone coupler right by the throttle body. I slid the piping back into the coupler and tightened the clamp. Hopefully this will resolve the issue. I'll report back after a test drive when I get the WG re-installed.


 


Buddha92SLC said:


> There is also a small boost leak inbetweeen the GReddy BOV and the flange. Right at the gasket. I'm thinking of smearing some black permatex on each side of the gasket to seal that better. Any suggestions on what product to use there? Black silicone is all that I could think of, but not sure if that would work to hold back 20psi of boost pressure.


 Is the flange warped? Why not just replace the existing gasket with a paper gasket-cheap shiit from Autozone (double up on it if needed so you can get some compression on it)? There should be no liquid/risk of saturation... just air.


----------



## DieGTi (Jun 19, 2001)

Silicone works great. Go for it. Doesn't usually take much.


----------



## masterqaz (Oct 5, 2007)

Suprised you didnt hear the leak while boosting, their usually pretty loud.


----------



## DieGTi (Jun 19, 2001)

A little aquanet where the pipe goes into the silicone can help hold together a slippery joint.


----------



## Buddha92SLC (Jul 22, 2001)

Ok the boost leak is definitely the problem. I had it fixed for about 10 minutes then the pipe slipped out of the coupler again. I pushed the piping into the coupler and tightened down on the clamp as much as possible without distorting the piping. Took it for a drive and had a great pull at 16psi, so I know the boost controller and wastegate are working correctly. 

I can't for the life of me keep this pipe in this silicone coupler. I've heard of using hairspray, sanding the outside of the piping to give it some grip, spraying carb cleaner or brake cleaner on the inside of the silicone coupler to make it sticky. A bead on the pipe should work, but I don't know anyone around here with a bead roller. 

l think it might possibly have to do with the coupler itself. All other silicone is from high temp silicone. That particular coupler was purchased at autozone. It seems to be silicone but a different consistency than the others. It is shinier than the others. Besides replacing the coupler and other ideas?


----------



## 'dubber (Jun 15, 2004)

Tighten the clamps some more, or find a longer coupler.


----------



## DieGTi (Jun 19, 2001)

You can weld a bead on if you want... I did just 4 or 5 spots on mine in the past. If you use this you'll have to pry the silocone off:

http://www.amazon.com/Aqua-Net-Prof...=1344959062&sr=8-3&keywords=aquanet+hairspray


----------



## masterqaz (Oct 5, 2007)

You can make a bead roller with locking grips and some washers. Seen it in a thread for boost leak testing.

Are you using t-bolt or worm gear?


----------



## Buddha92SLC (Jul 22, 2001)

It is a t-bolt style clamp. I'll try the aquanet first then report back.


----------

