Mitsu boost only 10 psi

[guidsm]

I have installed my SRT4 intercooler in my omni. In first gear a have 15 psi whit a grainger, in other gear gear i can not have more than 10 psi and the is boost slow to build. L'm on the downpipe only... Also my grainger does not have a little hole before it.
I have cheched for leak...i don't see anything..

Thank you

[jdawg]

It would probably help if people could actually understand what in the hell you are typing.

[guidsm]

xcuse me sir, i don't speak english.

[guidsm]

Anyway...another try :-)My Mitsu turbo hit 15 psi only in first gear, on the other gear i can not have more than 10 psi and not until 4500 rpm. I have check for leak but all look ok. I use a grainger to control boost. I have notice some oil on the compressor housing of the turbo.

[Big O]

Quote:

Originally Posted by jdawg It would probably help if people could actually understand what in the hell you are typing.

It would also help not to be ignorant.

[Stevien1]

Sounds like it could be a weak wastegate actuator spring inside of the can. The Mitsu turbo is so restrictive that in the higher gears (when there is more load on the motor), the pressure in the turbine is actually forcing the wastegate open.

A boost controller, like the Granger valve, can only set boost as high as the wastegate actuator can allow. So cranking it up will have little or no effect in this situation.

You can try shimming the existing actuator away from the compressor cover (two headbolt washers work great) in and effort to increase spring tension. However, by shortening the travel of the actuator arm, it'll be more prone to boost creap.

Finding a low mileage wastegate actuator with a strong spring is probably the best thing to do (aside of swapping in a REAL turbo). You could experiment with sending vaccum to the actuator to help hold it shut.....

-Chuck James

[guidsm]

Quote:

Originally Posted by Stevien1 Sounds like it could be a weak wastegate actuator spring inside of the can. The Mitsu turbo is so restrictive that in the higher gears (when there is more load on the motor), the pressure in the turbine is actually forcing the wastegate open. A boost controller, like the Granger valve, can only set boost as high as the wastegate actuator can allow. So cranking it up will have little or no effect in this situation. You can try shimming the existing actuator away from the compressor cover (two headbolt washers work great) in and effort to increase spring tension. However, by shortening the travel of the actuator arm, it'll be more prone to boost creap. Finding a low mileage wastegate actuator with a strong spring is probably the best thing to do (aside of swapping in a REAL turbo). You could experiment with sending vaccum to the actuator to help hold it shut..... -Chuck James

Great reply Chuck, i will take a look on that tomorow. :-)

[daytonairoc]

I would still think you have a boost leak. I run 15lbs on my mitsubishi all day long except for last weekend.

Turns out I had a boost leak for a long time. It was at the rubber eblow that supplies vacuum connections for the map, boost gauge and FPR. It finally got so bad that I couldn't make more then 10lbs of boost with my boost controller turned all the way up. That is a sure since of a boost leak. I disconnected my wastegate and still couldn't get more then 10lbs.

later