I installed a hallman mbc a few days ago and went out testing it to get the boost set to what i want. after several runs, probably 20 or so, i finally got it set to stock boost 19-20 psi. i went to take it out today, and the first time i hit boost, it spiked all the way up to 27-28 psi, but then it stayed at 20 after that, it hit high boost 1 time. then i was on my way home from work, and it did the same thing, hit 28 psi just once, then stayed at 20 in every gear

anyone know why it is doing this or how to solve this problem???

 

which vaccum lines are you running off of with your hallman?

 

i did it the way where the bottom of the controller goes to the turbo outlet, and the side nipple goes to the wga, capped off the intake and stock solenoid, intake manifold is connected to bov, i did no t splitting.

 

If you did it this way you shln't have any problems....
https://www.evolutionm.net/forums/ev...procedure.html
I've only seen problems from t-ing off the vacuum lines from the intake manfold and the bov/dv.

 

thats the exact thread i used, the very first picture is how i did it

 

what other mos do u have?

 

3" TBE catless, s1 cams, wideband

 

Usually the reason for spiking is because your wastegate hole is large enough, but your actuator is taking too long to fill with compressed air, so you temporarily overshoot your boost level.

Any actator mods whatsoever?

 

not that was i told when i bought the car, and i havent done any

 

The hallman came with two springs, which did u put in it?

 

the mbc came with the car when i bought it, he had installed it before but took it off. in a box there was a bag labeled hallman mbc heavy spring, or something like that, and it was empty, so im assuming he put that one in there

 

there shldve been a heavy and a light spring.

 

Double check the vacuum lines making sure they are not getting pinched.

 

Did you disassemble the Hallman and lube it? Maybe it is sticking.