Instead of sending the boost signal to the MBC then regulating it to the WGA, run it directly to the WGA. This should rule out the possibility of having a bad MBC, and in thoery, it should only allow u running whatever the WGA pressure rating is.

 

Basically what Detroit is saying is just take the 2 lines off your mbc now and join them together thus eliminating the mbc.

 

its an 18psi wga and its hitting 20psi only? what is the problem then? 2 psi over the wga target is not something to be concerned about.

is the boost curve spiking to 20psi and then holding and slowly tappering down? or is it creeping past 20 the higher in the RPM you go?

 

it hits 20 and thats it it stays at 20

right when i got the car tuned it wud hit 24/25 psi and stay there !! it wud hit full boost at 3900 until 8000 rpm !

this is why i think its the MBC bc i had a battery overflow and acid got INTO the MBC

 

the problem is MY CAR IS TUNED FOR 24/25PSI thats the problem

i tired turning the MBC up 2 full turns and down 2 full turns and it DOES NOT CHANGE THE BOOST

 

its a manual controller? it is possible that the battery acid got inside and corroded the spring i suppose.. did you test the car for boost leaks?

 

To what I gather from his first post, is that he was originally tuned for 24psi and now he's only getting 20psi. He ruled out a boost leak, maybe an ailing mbc?

 

if no boost leaks & wga is fine, then ya mbc is at fault here.

take the MBC apart and see if the spring got jammed .. it can happen. or the ball is stuck inside the spring..

 

I think that you should try turning the mbc until it maxes out in one direction. If there is still no change try a different one.

Here is a link to instructions on how to adjust it...http://www.addictiveperformance.com/...stallation.php

It basically says start with the controller turned all the way counter clockwise for stock boost level. Then slowly turn the knob clockwise until desired boost is reached.

If you max it out all the way clockwise in slow increments (one turn at a time) and it still doesn't work get a new one.

 

bought a new boost controller put the heavier spring in it turned ti all the way down and slowly did 2 full turns at a time which equals 5 psi now the boost stays at 25 !