Boost problems

[burbage2001]

Hello, I was running 13 psi until I installed my manual boost controller. Now I cannot go over 7 psi. I have done a boost leak test and all checks out good. Any help would be appreciated. Thank you.

 

[absolute_DSM]

Are you sure youre turning the boost controller the right way?

 

[Imback]

How did you hook up your boost controler?

 

[crimsondragon]

You made no mention of adjusting it...Did you try to adjust it at all? Boost controllers don't just regulate themselves you know....

 

[Eastwood95]

What brand of boost controller is it? How did you hook it up?

A few possible solutions:

A. Its hooked up incorrectly
B. You need to turn the boost up
C. The Boost controller is faulty. To check the operation of the Controller, you can hook up your MBC to another DSM and check the operation.

 

[Oblivion02]

Remember its a MANUAL boost controller. You have to adjust it yourself, like crimsondragon said: "they dont just regulate themselves".

 

[Boost92awd]

I bet you hooked it up wrong. Hence causeing a boost leak, this is why your only hitting 7 PSI.

 

[MountainDew]

I'm guessing you hooked it up wrong. There should be an arrow marked somewhere and that hose should be going to the wastegate.

 

[Boost92awd]

Are you sure youre turning the boost controller the right way?

He obsiously created a boost leak. Cause turning the boost controller all the way down would make it run off the wastegate, which is around 10PSI. Not 100% sure what PSI the wastegate opens on a 2G.


To the OP......

Visual Frequently Answered Questions - Home Page

 

[burbage2001]

Thank you for all of the replies. I did adjust he mbc both ways with no change. I installed the mbc to the using the hose from the wastegate and the line from the bov. I also switched to the 1g bov. After I hooked everything up I conducted a boost leak test and I had no leaks. I bought the mbc off of ebay. I do not know the name of it.

 

[firefightermdc]

ebay, i think you answered your own question

 

[nfernotalon]

Youre not suppose to hook it up to the BOV line, just hook it up to the J pipe and the WGA actuator..

 

[burbage2001]

Can you give a picture of exactly where the j-pipe is?

 

[Mr Peepers]

2g's don't have j-pipes stock, they have a nipple on the t25 compressor housing. Fill out your profile so we can help you better.

 

[kenamond]

Thank you for all of the replies. I did adjust he mbc both ways with no change. I installed the mbc to the using the hose from the wastegate and the line from the bov. I also switched to the 1g bov. After I hooked everything up I conducted a boost leak test and I had no leaks. I bought the mbc off of ebay. I do not know the name of it.

What did you do with the stock vaccuum line coming off the compressor outlet nipple? If it's a bleeder MBC vs. a ball-spring MBC, you have to hook them up differently. Also, turning the knob a turn one way or the other may not be enough. With a ball-spring MBC, you may need to tighten it several turns before it starts to increase boost...but once you reach that point, it may only take a quarter or half turn to make a big difference, so you have to be careful. You also need an aftermarket boost gauge with numbers on it so that you can tell what boost you're running at. If it settles on a boost pressure that is over 14-15psi, let off the gas, pull over, turn it down, try again. Most MBCs can't perfectly control boost when it first "hits" and will overshoot a bit (called a boost spike). My car spikes to 16psi and then settles on 15psi and stays there. Just be careful and make sure you don't overboost...underboosting isn't a problem at all (for your car).

If you have a bleeder MBC, you search for one of the other half-dozen threads I've responded to this evening and find the one that goes into gory details about boost control. Then you find the other one that talks about installing a bleeder-style MBC. Search is your friend!

EDIT: Here's all about boost control and a bit about bleeder MBCs:
http://www.dsmtuners.com/forums/new...-see-if-anyone-can-help-me.html#post151388599

And here's the correct ball-spring MBC setup:
http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/237982-best-way-install-mbc.html

 

[burbage2001]

OK guys, I have been messing with this all day and I still have not figured it out. I took the mbc off and hooked it back up the original way and I am still getting the same psi 7-8. I have checked for boost leaks and that checks out. Ideas please and yes I do have a aftermarket boost gauge.

 

[kenamond]

OK guys, I have been messing with this all day and I still have not figured it out. I took the mbc off and hooked it back up the original way and I am still getting the same psi 7-8. I have checked for boost leaks and that checks out. Ideas please and yes I do have a aftermarket boost gauge.

Can you post a picture of the MBC?

 

[burbage2001]

I have read that there is a bleeder type mbc and that these are installed differently than the ball and spring type. Is this true? If so how do they hook up?

 

[knochgoon24]

That MBC keeps turning up in boost problem threads... no one is having any luck with it. Might check around and see if you all got your MBCs from the same seller. Maybe the batch was bad. Or maybe that specific MBC is really low quality.

 

[MountainDew]

That MBC keeps turning up in boost problem threads... no one is having any luck with it. Might check around and see if you all got your MBCs from the same seller. Maybe the batch was bad. Or maybe that specific MBC is really low quality.

Could be that it's a knock off because my turbosmart one looks exactly the same and works perfect. Yet its a name brand.

Actually now that I look at it, mine is slightly different. There is no separate piece to go to the wastegate and there is a nipple on each side, not just two on one side.

 

[Eastwood95]

I concur with that MBC being crap. My buddy bought the same exact one for his EVO8 and we could not get it to function correctly. You need to get a REAL Boost Controller. I'm not saying you can't use Ebay to find one that works, because I did. Anyways, as far as getting 7-8 psi after going back to stock is strange. You either hooked it back up incorrectly, or your wastegate actuator is crap.....

Do you know any other local Dsmr's? If so, you can try to swap their controller in/out of your car to verify if your system is working correctly....

If not, can you explain in detail how you have your setup and what/where you got the reference for your installation...

 

[DSMLaser90]

Do you have a picture of the way you have the MBC hooked up?

 

[Calan]

Go back to square one and systematically troubleshoot this, instead of using a shotgun approach and assuming it's a defective MBC (which it may be).

1. Pull the actuator arm off the flapper at the turbo housing. Does it move freely?

2. Slowly put some air into the actuator from a compressor or other source. Use a gauge so you can monitor pressure, and see if the actuator opens properly and at what pressure.

3. Blow through the MBC (both sides) while adjusting it. Does the airflow change? Make sure you know which side is the input and which is the output going to the WGA.

4. For a ball/spring MBC...blow through it and adjust it until it just starts restricting airflow, and then give it an additional 1/4 to 1/2 turn. This will be at or just below stock pressure. So now when you hook it up, you'll know roughly where it's adjusted to. You can probably do something similar with bleeder types, but I haven't tried one.

5. Hook the vac hose straight from your compressor or J-pipe to the WGA.. you should see steady boost, limited at whatever pressure your WGA spring is rated for.

6. Check for exhaust leaks before the turbo (head-to-mani, and mani-to-turbo). If you have a leak there, you'll have a harder time building boost.

BTW - What does "boost leak test and all checks out good" mean? How much pressure did you test to, where did you hook in, and how long does it hold?

 

[kenamond]

Go back to square one and systematically troubleshoot this, instead of using a shotgun approach and assuming it's a defective MBC (which it may be).

1. Pull the actuator arm off the flapper at the turbo housing. Does it move freely?

2. Slowly put some air into the actuator from a compressor or other source. Use a gauge so you can monitor pressure, and see if the actuator opens properly and at what pressure.

3. Blow through the MBC (both sides) while adjusting it. Does the airflow change? Make sure you know which side is the input and which is the output going to the WGA.

4. For a ball/spring MBC...blow through it and adjust it until it just starts restricting airflow, and then give it an additional 1/4 to 1/2 turn. This will be at or just below stock pressure. So now when you hook it up, you'll know roughly where it's adjusted to. You can probably do something similar with bleeder types, but I haven't tried one.

5. Hook the vac hose straight from your compressor or J-pipe to the WGA.. you should see steady boost, limited at whatever pressure your WGA spring is rated for.

6. Check for exhaust leaks before the turbo (head-to-mani, and mani-to-turbo). If you have a leak there, you'll have a harder time building boost.

BTW - What does "boost leak test and all checks out good" mean? How much pressure did you test to, where did you hook in, and how long does it hold?

He's underboosting, not overboosting. I recommend that he reads my post that steve recently responded to. Steve pointed out that there is a restrictor plug in the stock vaccuum line between the compressor outlet and the T fitting. If it's not in there, the bleeder MBC can't leak enough air to affect the WGA signal. This might be why the MBC can't raise boost on the OP's setup. I'll paste the thread link in a second.

EDIT: Here it is.
http://www.dsmtuners.com/forums/new...l-turbosmart-tee-style-bleeder-style-mbc.html

If the OP can try using the stock vaccuum line with the plug in it, and it works, PLEASE respond to the thread linked above so that we can put a tech article together that is accurate.

 

[Calan]

He's underboosting, not overboosting.

yeah... but still doesn't hurt to check everything out systematically. It's probably the MBC, but since we don't know everything that was done during his install, it wouldn't hurt to start from the beginning and check other things such as stuck open flappers/WGA, exhaust leaks, etc.

Is all I'm saying...