1psi full boost?

[mr2turbo]

alright I just finished the 50-trim install 2 weeks ago I've been taking it easy so far, so today I decided to turn up the boost and take it around the block. well all I can get is 1psi maxing out the MBC, I have no boost leaks, the compressor wheel turns fine. the wastegate is closed when I'm not trying to boost, and the turbo spools fine, what could be causing this?

 

[spinz4]

What wastegate are you running? Internal? Seriously sounds like a boost leak though. When you say the turbo spools fine is just wrong...If the turbo spooled fine maxing out the MBC would give you some results.

 

[GVR4592]

Sounds like a wastegate problem. You should fill out your vehicle profile too.

 

[Bodack]

Where is the mbc connected at? Where is the gauge tapped at?

 

[rst95eclipse]

Focus on the wastegate. It sounds like your vac line to the wastegate is where you should start.

 

[spinz4]

Thats what I was thinking as well.

 

[pooker]

If you bought one of those cheap ebay external wastegates that might be your problem, my friend bought a knockoff one and the spring would not hold past 5 when he ordered one with a strength of 15 psi.

 

[mr2turbo]

well it will hit 1 psi and max out there around the time it normally hits 1 psi, MBC is between wastegate and BOV line, the gauge is tee'd off one of the solenoids on the firewall by the driver's side. it's internal wastegate, I'll do another boost leak test and tinker around with the wastegate

 

[GVR4592]

The actuator arm probably fell off the flapper.

 

[mr2turbo]

like off the turbine side? it's still on there

is it possible I have my MBC on backwards?

 

[Novablue454]

The MBC should be tapped to the wastegate actuator and the fitting on the J-pipe. Running it into the BOV line could cause issues.

 

[mr2turbo]

what if you don't have a j-pipe?

 

[exile]

Novablue454 gave you a very circumstantial answer. I'll broaden what he is trying to say: The feed to your MBC must come after the turbo and before the throttle body, preferably as close to the turbo as possible, which in most cases is on the J-Pipe for up facing turbos.

If you could possibly tell us what kind of wastegate you currently have, and possibly the brand and model number of the MBC. There are pictures on this site of a MBC that is connected to the BOV line that Defiant made a LONG time ago. Do NOT follow that picture.

What if you don't have a J-Pipe, and there's no where to tap along your pipe? What if (like me) you are afraid to tap your metal pipes because you may start an annoying leak? Well, there's one option for you to try that I am extremely pleased with an I use today.

You can find this thing on a Volkswagen parts site, I ordered it and it works 100% no leaks at all. I tapped the coupler that connects to the compressor outlet on my turbo.

http://www.atpturbo.com/Merchant2/m...OD&Product_Code=ATP-FTG-010&Category_Code=BCS

But Mr. Justin, what if I don't want to buy that? Then you can connect it to a port after the throttle body (on the intake manifold) but it is NOT recommended by alot of posts on this forum. The closer to the turbo, the faster the response, the less creep the better you'll be.

 

[fwdeclipse]

If the manual boost controller was put on backwards he would be running unlimited boost. It either has to be a giant boost leak or the wastegate actuator is not working properly.

 

[SleeperG]

seriously such a large turbo shoudln't be able to flatline at 1 psi no matter what you try,
you'd figure it woudl start to creep.

i had a similar problem with my 50 trim when i installed it.
i ran an external gate mounted on a sbr manifold.
i coudln't get over 5 psi for the life of me.

no matter what i tried nothing yeilded results,
in the end,

it turned out that the 14b turbine whell that i thought had shot out my exhaust...(it usre as hell sounded like it you coudl hear it ping panging its way down the line) was wedged between my rear o2 sesnor and the exhaust pipe.
once i got that out(found it when i was replacing a gasket)
it boosted in all of its 50trim glory after that.

pehaps you have a exhaust restriction,

or a massive exahsut leak(preturbo)

 

[oldman]

alright I just finished the 50-trim install 2 weeks ago I've been taking it easy so far, so today I decided to turn up the boost and take it around the block. well all I can get is 1psi maxing out the MBC, I have no boost leaks, the compressor wheel turns fine. the wastegate is closed when I'm not trying to boost, and the turbo spools fine, what could be causing this?

1. You have been asked nicely to fill out your car profile, it will make helping you easier.

2. Although probably not related to your problem, they are right about not tapping the BOV line for more precise boost control but more so for proper BOV operations.

3. What exactly do you mean by "all I can get is 1psi maxing out the MBC"? Do you mean you're only boosting 1psi? You mentioned "I've been taking it easy so far, so today I decided to turn up the boost and take it around the block", does this mean you were able to boost past 1psi prior to fiddling with the mbc?

4. Which mbc?

5. How did you come to the conclusion that there are no leaks? How did you test and what were the results?

6. Where are you tapping for your boost gauge? What is the vacuum reading at idle?

7. Do you have an adjustable actuator? If so, have you check and make sure that the flapper isn't opened due to improper actuator adjustment?