I just bought this car like 3 weeks ago and it has ams intercooler with ams lower pipes, full cat back exhaust and downpipe, and megan header, also has hallman bc nd my car only runs 11psi when i floor it what can be wrong? i took of the boost controller and took the car on the highway in 5th gear at 4000rpm and gave it gas the psi gauge went to about 20psi or more. i cleaned the mbc and put it in and still same, i got a new one and still same. what could be the problem?

 

First off go get it tuned before you do anything else. Your tuner will adjust your psi accordingly.

 

Make sure you have the right spring in the MBC.. Hallman MBC's come with multiple springs for different levels of boost.

 

https://www.evolutionm.net/forums/ev...an-pro-rx.html

Check for leaks as well..

 

Do a boost leak test, spark plugs, cat..maybe its clogged.

 

Wouldnt be surprised if that junk manifold is cracked. That will easily throw off boost

 

what junk manifold?? there is no leaks or anything the spring is okay because i tryed another mbc and still the same thing.....

 

Stock wastegate is 11psi I think.

 

so do i need to change the wastegate? get a 25psi one?

 

boostleak test bro

 

their is no leaks...

 

Hmmm. The wastegate on the MHI 16G turbos is adjustable. From your description it sounds like yours is adjusted to the lowest setting or what is called base wastegate pressure. You need to increase the wastegate spring pressure.

The WGA has a threaded actuator rod which attaches onto a peg of the wastegate flapper valve's pivot arm. There is a turnbuckle with internal threads positioned at the end of the threaded actuator rod. the turnbuckle has a flat with a hole held onto the pivot arm via a cotter pin and further secured by a backup nut.

I gotta go out to work now but you can do a search and familiarize yourself with the adjustable wastegate assembly.

The MBC just controls boost above spring pressure. Essentially you are going to have to raise the wastegate's spring pressure.

 

well what about when i took off the mbc and took the car in boost it went over 20 psi it didnt spike it was there for like a sec untill i took my foot of gas... so i guess the wastegate is ajusted normaly then?

 

stock wastegate is 11psi.. if anybody still has the stock wga pull off your mbc or ebc and do a pull it feels like somebody stole your man card. thats more than likely what happened.. just check your vaccum lines and make sure they're all connected

 

"megan header" = complete trash