Won't boost past 15psi

[crazyquik22023]

Problem is car won't boost past 15psi no matter what. Profile is up to date. 6262 turbo is about 3000 miles old. Before I recently got a new motor the turbo wouldn't boost past 20 and now not past 15. Got new buschur motor about 2 months ago. Checked tial 44mm springs are good, diaphragm is good, Hallman pro boost controller turned up all the way with heavy spring, boost leak tested and only 1 small leak that I cannot get rid of is on the top of my greddy type r bov where the adjustment screw is. Def not enough of a leak to cause a problem like this. At least I don't think so. If anyone has any other ideas what the problem could be let me know. Thanks

 

[JusMX141]

Any unusual sounds from the turbo? What spring is in your wastegate? If you only have a 7psi spring, this situation is highly possible.

 

[crazyquik22023]

Dammit I knew I forgot to add something. Wastegate has 1.1 bar springs. Big green and small red. Turbo sounds good and has no shaft play.

 

[Ethand14]

My downpipe wouldn't let me boost past 12. You think your exhaust is restrictive in any way

 

[crazyquik22023]

My downpipe wouldn't let me boost past 12. You think your exhaust is restrictive in any way

I don't think so. I'm running a custom 3.5" downpipe going to a straight 3" exhaust. No cat.

 

[josh1095]

im a noob so take this with a grain of salt, isnt 1.1bar around 15.5psi?

 

[SHEARER_TSI]

Yes it is so that should be the minimum amount of boost he is running.

 

[crazyquik22023]

Yes, 1.1 bar is about 15psi which is what I am maxing out at. Which would lead me to believe that my problem is the boost controller. I just replaced the spring in the boost controller and everything looks normal. I don't see anything that would cause the controller to be the problem. I will try another one out when I can borrow one from my buddy.

 

[Bud92gsx]

It couldn't be the exhaust causing him to not boost past 15psi..I have stock DP and My 16g would creep past 15psi..

 

[SHEARER_TSI]

This is going to sound dumb but, have you checked to make sure the boost controller is hooked up correctly?

 

[crazyquik22023]

This is going to sound dumb but, have you checked to make sure the boost controller is hooked up correctly?

yes, side port going to the wastegate, bottom to the compressor.

 

[Ethand14]

how did my megan racing downpipe stop me at 12 psi when I put my punishment racing downpipe let me boost to 20+.

 

[Chrispy0530]

Just a ball park guess. I'm not too familiar with the 6262 turbo, but I'd assume you have the Flapper on the hot side sealed/welded shut, correct? I recently went through this problem on my turbo and the culprit was my door being wide open. Was really hard to build any boost.

 

[crazyquik22023]

Just a ball park guess. I'm not too familiar with the 6262 turbo, but I'd assume you have the Flapper on the hot side sealed/welded shut, correct? I recently went through this problem on my turbo and the culprit was my door being wide open. Was really hard to build any boost.

I have a 6262 with a t4 hosuing. It uses an external wastegate, no flapper.

 

[crazyquik22023]

Update: Did another BLT tonight and found it still would not hold any kind of pressure no matter what. Fixed the small leak on the top of the BOV, found another leak on where I teed my boost gauge and found a huge leak on the vacuum line going to the boost gauge where it actually connected to the gauge. Odd place for a leak if you ask me. The line was almost all the way off. Fixed that and redid almost every coupler I have with new clamps and making sure they are as tight as possible. Didn't take it for a drive yet but I will post back when I do and hopefully my problem will be solved.

 

[Spanky_DSM]

Im currently having this issue on the t 25.. i unhooked the wastegate and capped off the boost source and at wot it wont go past 15psi. No boost leaks at at all.

Could it already be stuck partially open?

 

[UrN2nd]

Question. If the waste gate has a 15 psi spring in it won't it be forced open at 15psi no matter what?

 

[99ECLIPSEGSXDSM]

Not if you have a properly working boost controller. 15 psi would be the least you could run (on his setup).

 

[GofaST4life]

Check the lines to your MBC for debris.

I noticed one day I was running waste gate pressure only, checked my lines and found some debris which was making the MBC useless, allowing the ball to not seat correctly.

 

[Cdc1221]

how did my megan racing downpipe stop me at 12 psi when I put my punishment racing downpipe let me boost to 20+.

A more restrictive exhaust will actually build more back pressure, choking the engine up, and allowing boost pressure to build. If your 'goal' is to run 20 psi, you should be able to no matter what exhaust is on it. It does effect mass airflow though. I ran my s16g at 20#, then 25#, and could get no more then 28#s/min, on a stock exhaust.