Boost problem

[aCer_209]

i'm having a problem with boost.
when i hit the gas the turbo spools up fine but it wont stop boosting and its peaking at wot.
my boost gauge only goes up to 20psi and it goes well passed that.
car has no boost leaks.
no bc yet but i have the hks evc, just havnt installed it
whats causing this and what can i do to fix this?
would adjusting the wga fix it?

thanks for taking the time to help.

current setup: K&N Intake, HKS SSQV BOV, 3" Thermal Research cat back exhaust, Megan Racing 3" dp(catless), DNP turbo manifold, Evo 3 Big 16g

 

[jeepzj94]

Definitely check your wastegate. Doesn't sound like its opening to me. Make sure the arm is still attached to both the actuator and the flapper.

 

[mmmmbst]

Also check the vacuum line going from the wastegate to the boost solenoid, or the Mnaual Boost Controller, whichever one you have. But it does sound like the wastegate is not opening. Good luck!

 

[slowstang]

Since you dont have a boost controller and if you dont have a stock mbc the only solution you have is to run a vaccuum line from the nipple on the jpipe to the waste gate. That would limit your boost to the wastegate spring pressure (probably ~10psi) but it's safer than an uncontrolled 20+psi.

 

[xdxoxuxgx]

Sounds like one of your vacuum lines is hooked up wrong, I had this problem when we first put my MBC on, we put a vacuum line on a wrong source and the turbo wouldn't stop boosting.

 

[aCer_209]

the arm is ok. its connected to both sides. but the bcs has only 1 line going to it. its the one coming from the wga. where is the second line supposed to go? could that be my problem?

 

[No_Skillz]

Nipple on the compressor cover.

For now you can connect the WG directly to that nipple. You will run stock boost ~11-12psi.

Leave the BCS plugged in to the electrical line but no vac lines.

 

[snowborder714]

My guess is that you won't have a nipple on the compressor cover since you have an Evo III (although I could be wrong...). So you will have to get a boost source from elsewhere. If you don't have a nipple on the compressor, you might want to think about putting on on the J pipe. Or you can just run a vacuum line from the intake manifold which will work perfectly fine.

 

[aCer_209]

yeah theres no nipple on the compressor. so i should run a line from the intake mani to the nipple on the wga?

 

[snowborder714]

If you're going to run a line from the intake manifold, I would hook it up to the BCS or get an MBC. This is because the longer the line running to the wastegate the slower it reacts.

Or drill and tap your J pipe and JB Weld a nipple on there.

 

[aCer_209]

alright i'm going to give that a shot this weekend.
thanks

 

[xdxoxuxgx]

X2 on the drill into the j-pipe and jb weld a nipple onto there, that's what I did, works just fine.

 

[No_Skillz]

Whoops, didn't catch the E3 16G.

Before you tap the J-pipe, look along your intake tract first. Your vac hose might have just fallen off. I doubt anyone who goes through the hassle of installing a turbo would lack the oversight to have a pressure source.

 

[habitatguy187]

If you don't have a bigger or ported o2 housing you're going to get boost creep also with the 3in downpipe and cat back system. So you could have mutiple problems going on here.

 

[aCer_209]

so today i was going to tap into the jpipe, but before i did that i checked the bcs and i noticed that the second hose was pinched. well i got that fixed and now the boost stays between 17 and 19 at wot. when it hits that range in boost it feels like the turbo hesitates to keep spooling. so now if you guys could help me out with that i'd really appreciate it.
(hoses on intake tract are connected)