Turbo is very loud under boost lately

[Te37]

Tuesday when i was driving i noticed my car (sr20det with s15 dbb, greddy boost controller, 13psi) got very loud under boost. It sounds like some one took an air compressor and is spraying it under my hood when im in boost. I thought boost leak but my gauge still shows 13 psi like normal, and my boost controller didnt peak or anything like the turbo is being over worked to make up for the boost leak...maybe it is, dont really stare at boost controller in wot. My profecb normally is in the 120s-140s range. Any thoughts? It doesnt seem to pull me in the seat like it used too...but i have gotten kinda used to it over the year.
Thanks,
Nick

[ultimateirving]

exhaust leak? check the mani studs, turbo to mani studs, and ur downpipe...
Recently i found out 1 of my downpipe bolts was MIA.. and was leakin pretty bad. Normally exhaust leaks dont impact performance to much

[Te37]

You were right, i can see black all over the back half of the exhaust manifold from where the gasket is leaking from either the mani/turbo or turbo/jpipe, or both.
http://i306.photobucket.com/albums/nn257/KILLERSKITTLE/turboloose.jpg
On the 5 bolt jpipe flange there is a bolt/stud mising, and on the manifold 4 bolt flange the rear left bolt/stud looks like it is wiggling its way out.
Can some one please tell me where BOLTS and STUDS go. I know it sounds like a silly question but does the turbo 5 bolt flangs bolt in or uses studs? Does the 4 bolt turbo flange use bolt or studs there?

p.s. anyone know where i can source the lock plate for the turbo flange and copper(some different metal i heard of someone using because of the constant heat and cooling) bolts.

Thanks,
Nick

[turbociv910]

just cuz its reading 13 psi doesnt mean its not leaking.

[ultimateirving]

on my exhaust outlet i bought a stud kit and used all new studs.. as far as the 4 bolt flange to the turbo, use bolts to connect. THey do make different locking nuts, the ones i used on my 5 hole studs, were crushing. basically one time use, then u have toreplace the whole stud, so it will never come loose (hopefully)

[Croustibat]

these only use studs. Order them from nissan.The metal locking plate also comes from nissan.

Bear in mind they are not exactly cheap, i think that was 8€/stud ... but they do the job. Some people told me i was crazy to buy nissan stuff... but on my car, turbo has never unbolted itself. Never. Must be for a reason ;)

[Te37]

I always agree with going oem (they are in now and have rattled loose with locking plates also). I think the reason the oem stuff loosened up is because the previous owner used nismo motor mounts and has a crappy custom welded down pipe that I bet was never done properly so it was mounted at a weird angle causing pressure on it constantly as the motor moved around. My solution, short of welding the turbo to the mani, is all oem gaskets again using stage 8 fasteners (pretty neat shit) and a Megan flex pipe. My manifold to engine is still as good as new do I will be using all new oem stuff to hold that on.
Where did you get your oem studs and hardware?

I was also going to go the nordlock route but I heard they don't hold up well in high heat unless you custom order some...$$$$

[Te37]

Alrighty, tore it all apart this morning. Why didn't some one warn me it was gonna be a pita. The biggest hurtle was the coolant return line that wraps around the rear of the engine I couldn't access it from the rear so I had to remove it from the turbo banjo bolt, should be fun putting that back on haha.
Other thing I found out was that the turbo nuts/studs got seized together so it basically turned it into a bolt and still loosened up. I might try safety wire and drill through the nut & stud to wrap the wire around.
Some one tell me how these locking plates are supposed to do their job like this: (not my work)
http://i306.photobucket.com/albums/nn257/KILLERSKITTLE/e2284331.jpg

[ultimateirving]

Turbo is a major pita, first time i did it took forever. I just took my turbo off last night and its much easier with practice, only took me like an hour to pull it off working at a leisurely pace =)
and yes a lot of my studs were froze, turned into bolts basically. Pic doeesnt show up on my work computer sorry