ok 2 months ago I bought a auto meter boost gauge at full boost I would get about 21psi. i ran it like that for about a week or two. I bought a header, turbo outlet, and down pipe. for the test drive I got on it and I could only get about 15-16 psi I made sure every thing was hooked up right and test drove it once more. same thing the pull of the car felt a little faster. a week later i put my mbc in. it was a Hillman with the light spring ( i didn’t know at the time that with the mbc turned up all the way with the light spring would still not change the boost.) but right away it was right back to regular 21 psi i have not pushed it since just in case some thing is wrong. can some one help me with this problem

 

Do you have a tune at all? If you turn your boost controller all the way down, you should be boosting at wastegate pressure.

 

i dont have i tune but u would think that the boost would stay the same with a new header and outlet and dowm pipe

 

With no tune, turn down your boost with your MBC to ~18psi. As long as your MBC works now, you're fine.

 

i was just wondering why i would drop 8 psi just becouse of a header and outlet. when i turn it all the way down it goes to 21.. my gauge could be off tho that is waht it was doing befor i put in the stuf

 

Turn your boost all the way down and try another gauge. If you arent seeing 12-15lbs, then you hooked up your MBC wrong.

 

ok i will try that if i can find another gauge. how much boots can you run on 91?

 

I wouldn't run more than 18 on 91 with no tune.

 

19 psi is stock.
turn your MBC all the way down and make sure you read 11psi (waste gate pressure)

 

ok i turned it all the way down and i just stays at 21 ( its what my gauge says dosent me its not 19 cuz that is what it was befor i put the mbc in) i dont think i hooked it up backwords >>>http://www.hallmanboostcontroller.com/howto.html<<<
thats how it is hooked up