in the beginning of winter, I upgraded my exhaust manifold since my factory on cracked, and my car has only been out of the garge made 3-4 times all winter long and since it is going to warm up soon i would like to get the this issue fixed.

Issue: I get great boost 15-18psi till i drive for more then 10 mins, then after 10 mins or so, it won't boost for crap 10-12psi if im lucky, and it sounds as if the turbo is spooling but not doing much as far in power, and sometimes under heavy throttle it will just drop boost and the dv will open then closed and spool again.
I have done 4-5 boost leak tests, and i have no leaks. the other thing i have notced is that i have a forge unos manual boost controller and i can turn it all the way up or all the way down and nothing happens.

This issuse started happening after my factory exhaust manifold cracked and I had to limb it home about 10 miles the next day I installed a high flow manifold from Kinetic motorsport.

I am starting to think the turbo is headed out or the waste gate is toast, but what do you think????

 

Anyone??? i have editted it so maybe it makes a little more sense

 

Just a shot in the dark here but how long does your car stay in low boost mode? Can you turn it of and it resets to normal or do you have to wait quite awhile for it to behave normally? You didn't mention any CELs so I'm going to assume it's not electrical in nature. That could be verified by turning the car off and restarting and the problem went away for a minute.
I'm thinking more along the lines of the manifold surface not sealing good against the head and after the motor comes up to temp you have a slight manifold/head leak which would cause exactly what you're talking about. When the motor is cold everything is fine, after it heats up the exhaust leak prevents the turbo from producing power as it should. When you are able to apply full throttle and overcome the leak momentarily, the sudden pressure spike opens the dv and you're back to square one. The leak test wouldn't show anything because the cold side isn't the problem. If you are absolutely sure the manifold is sealing correctly, next take a look at your manifold to turbo studs/bolts. Hope this may be of some use. Good luck.

 

how do you have the mbc hooked up? using the n75 or not?

How did you tighten the bolts on the manifold? you should start in the center and go out to the edges evenly.

 

Till i shut off the car any let it cool down.

no cel nor any stored in memory

that makes sense.

 

not using the n75 it is plug in and capped off


these are the install insturctions i used
http://www.atpturbo.com/root/help/pd...tock_Loc_1.pdf

 

I cant open adobe cuz my computer is all fecked... but the nuts for the manifold to the head need to be tightened starting from the center and going outwards in an even fashion. This ensures a good seal on the gasket. Also did you happen to snap off a bolt in the turbo and not realize it? (sometimes they break pretty evenly). If it is leaking you should be able to tell on a cold start by just feeling around the edges... Also you didnt change anything with the mbc hookup when you did the manifold did you?

 

metal expands when it heats up, so when the engine warms up, it shouldnt cause a leak even if the bolts are not tight enough.

 

dillusional thoughts, yes metal does expand, but if the manifold isnt on right then it can still leak.

 

I know that, but it doesnt leak when its cold so Im saying that the chances are that it would leak all the time if it just wasnt tight enough.