turbo over boosting

So my latest issue is that my turbo is boosting to 20-25psi good right? wrong well only problem is I haven't installed my lsp mbc as yet. I was waiting until I got the car dialed in correctly before upping the boost. From doing some searching most likely culprit seemed to be the hose to the actuator being cracked which would cause the wasteagate not to open. Well I checked that and it fine, its actually a silicone hose any ideas? I like the idea of running more boost but not when I am not controlling it wth?

 

[524of1000]

Perhaps the wastegate itself is malfunctioning? Try pulling it off and pressurizing it to see if it still works. If not, the wastegate to exhaust outlet may be blocked or not big enough /ubbthreads/images/graemlins/dunno.gif

 

[BoostedAWD91]

What Turbo you running

 

Mhi big16g

 

I will give that a try i dont think its too small I am almost sure its ported. Its a never ending battle isnt it?

Quoting 524of1000:
Perhaps the wastegate itself is malfunctioning? Try pulling it off and pressurizing it to see if it still works. If not, the wastegate to exhaust outlet may be blocked or not big enough /ubbthreads/images/graemlins/dunno.gif

 

[mikus]

when did this start, and what hardware are you running exhaust-side (mani, turbo specifics Eg ported or not, exhaust)

 

[Nartanian]

Is it creeping that high? Because you mentioned it's 20-25psi. Not a set point.

 

Started a few days ago ported 2g manifold, ported big16g, 3"turbo back exhaust no cat.

quote name=mikus]when did this start, and what hardware are you running exhaust-side (mani, turbo specifics Eg ported or not, exhaust)

 

Yea it will boost to whatever my right foot tells it to I dont let it go pass 25psi though.

Quoting Nartanian:
Is it creeping that high? Because you mentioned it's 20-25psi. Not a set point.

 

[onesickcrx]

So it never did this befor with the same setup?

 

[Nartanian]

Sounds like the vacuum line isn't hooked up correctly or your wastegate isn't opening for whatever other reason. I know in the winter time a setup like that will cause creep up to like 25psi though. Especially with the 3" downpipe.

 

I've seen the flapper shift laterally in relation to the hole. Think of a penny as the wastegate hole and a quarter as the flapper. The penny should be centered in the quarter. I've seen the flapper shift to the inside and get stuck. Think penny on the edge of the quarter instead of centered. I don't know how else to explain it but it shifts enough that the flapper can't physically open, yet it still seals the wastegate (barely).

Edit: Upon thinking more about this, I believe that this occurred on an "ebay" 16G. Not a MHI.

 

No was boosting 10-11psi before no problems...
quote name=onesickcrx]So it never did this befor with the same setup?

 

[onesickcrx]

There is something wrong with your internal gate which you can test or your vacume line has a big hole or crack in it.

 

As i posted before the car was working normal 10-11psi before it started so I dont think its the vacuum line not hooked up properly.
A stuck or defective wg sounds more like the culprit to me. Guess I will have to bouble check both again...

quote name=Nartanian]Sounds like the vacuum line isn't hooked up correctly or your wastegate isn't opening for whatever other reason. I know in the winter time a setup like that will cause creep up to like 25psi though. Especially with the 3" downpipe.

 

I have blown out a diaphram in a wastegate before. It wasnt on a 16g but it was on a fp green. You could always add vacuum to the wg and see if it opens and closed properly.

 

Did that opens and closes normally

 

[talontyme]

I would recheck that so called silicone line,some of the lower grade stuff has a tendency pinch off or balloon or lose it's structurally integrity after being heated(to close to the turbo).

 

Talontyme you were right on the money can't believe if took me so long to find this out my so call superior silicone vacuum hose between the mbc and the turbo wastegate had a leak and then it just finally ripped in two. It was hidden down behind my hardpipe so it was hard to see after replacing that bitch the car is a 100 percent better no more overboosting no more crazy knocking car pulls strong and clean saw only 1 count of knock under a hard pull. Now I need readjustment on my fp regulator to get my fuel trims back in line a bit rich right now going to do a full boost leak test this week also and hopefully get my big front installed by fabricator John from performance and styling in Manchester ct(shameless plug lol) we are giung to thru it on the dyne after ghat yea got one of those at the shop and see what she can do. I think I may also need a new battery and or fuel pump too the O2's go lean under full boost and I noticed tonight with all the accessories running my battery voltage goes down below 12 volts and the fuel pump gets loud hen it has a constant 12 volts are better and this was just sitting at idle. When I turn all the accessories and lights off the logger shows 14volts or better my low fuel trims also for some reason go up when the heat is on full blast at least to a 100 or more as soon as I turn of the blower switch the bitch goes back to 81.2 percent grrrrrrr. I still encounter some knock when I hold full throttle for extended periods of time 7/8 counts but I think this may be related to the fuel pimp and or battery as well as my stock intercooler piping and too much boost lol. Time to do some work but good heads up on the vaccuum line can't believe the difference it's incredible.