getting sick of only being able to run 8lbs of boost

[twalters09]

Hey guys, so this has been an ongoing problem for me. I had the same problem on my 14b but I could atleast get about 12 out of it. I installed a new big 16g Mitsubishi turbo. I don't think I have 2 bad wastegates in a row, plus I am able to run wastegate pressure on this one but I did a blt and it came out fine. I hooked it up to the turbo and sprayed everywhere with soapy water, no leaks, I did the test up to 30 lbs. I've tried many different adjustments on my mbc and it doesn't change. I'm really stumped. Any help would be awesome. Thanks guys.

cmon guys a little love on this subject would be greatly appreciated. i am really getting pissed off about this, i just went through and updated my mod list so everything should be pretty damn close.

 

[gofer]

Check for pre-turbo exhaust leaks using Seafoam.

Completely REMOVE your boost controller and just run a vacuum line from the IC pipe to the wga, this way you eliminate any chance of it being the problem.

 

[twalters09]

I already did run a line from the wg to the nipple on my jpipe. Still at 8 psi, what do you mean a pre turbo leak?

 

[TJCTalon]

Like exhaust leaking before the turbo there for spool up time is slower and if bad enough you wont build much boost. Like gofer said suck in some seafoam and that will show if you have any leaks and clean your motor out at the same time

 

[gsxkid81]

unplug the vacuum line to the wg all together.you will know then if its in the turbo side or vacuum line side.just dont keep foot in it if it builds boost pass 15 psi or so

 

[crash89]

Also when the engine is cold just look around your manifold, you could a crack in that tubular mani. Or its not sitting flush against the head. Like stated above ^^^ try some seafoam!! Good luck!

 

[gofer]

I already did run a line from the wg to the nipple on my jpipe. Still at 8 psi, what do you mean a pre turbo leak?

Your exhaust coming out of the motor is what spools the turbo creating boost, if the exhaust is escaping (a leak) before the turbo then it won't build boost.

See the below diagram...

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[jwahl16]

Haha great diagram, i love the snail.

As said, check for cracks in your exhaust manifold by visually inspecting it (when cool) or by using seafoam. Don't forget to change your oil etc. after seafoaming.

 

[tturbolife1]

Same thing was happening to me I found out the solid peice of metal (gastket )between my exhaust mani and turbo was cracked ,a hair line crack and once I changed it. It was still not boosting the numbers I was telling it to ,theni figured out my $10 mbc was bad?

Isnt seafoam bad?for the Turbo seals and such? And after seafoam,why check the oil?

 

[johnmarines]

Check for a obstruction in your exhaust. I had a similair issue at one point and it ended up being my flex section had colapsed and was only allowing the exhaust to flow through a 1" hole.

 

[gofer]

Check for a obstruction in your exhaust. I had a similair issue at one point and it ended up being my flex section had colapsed and was only allowing the exhaust to flow through a 1" hole.

This too ^^^ as well as a bad catalytic converter (if you have one) will limit your boost, maybe your neighbor kids shoved a potato in your muffler?

 

[johnmarines]

maybe your neighbor kids shoved a potato in your muffler?

Boy I remember that movie... eddie.... he was the bomb!!!

 

[twalters09]

Ok so I just put two new gasket on my manifold, the one at the motor and the one at the turbo. I don't see my mbc being bad, its a ball and spring, how can that go bad? So of this doesn't work could it be the exhaust? I just am really getting tired of fighting this damn thing.

i just got back from a test run, i only can get 10lbs with my boost controller screw all the way in. could it be my wastegate even if i ran the loop from the wg to the nipple on my jpipe and ran 8psi, but i really doubt ive had two wg in a row bad...but i guess it is possible.

or can a ball and spring mbc go bad?

 

[johnmarines]

Drop the down pipe... wire it to the side so you will be running open dump and take it for a test drive... it will be loud but you can eleminate the exhaust .

 

[twalters09]

I am in the process of that right now

 

[gofer]

YES a MBC can go bad, they get stuck or they just suck in general if its an eBay knock off. Even then good MBC's can go bad... if you pull the vacuum line OFF of the wastegate actuator so it doesn't know when to open the flapper you should be able to build 26psi+ if you aren't careful.