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Engine Specific Info and Questions => IDI Engine => Topic started by: jeff115 on September 10, 2012, 05:47:59 pm

Title: exhaust studs keep braking
Post by: jeff115 on September 10, 2012, 05:47:59 pm
is it common for the exhaust studs to brake? the four studs on the two passenger side ports brake all the time, usually in less than 500 miles? ???
Title: Re: exhaust studs keep braking
Post by: R.O.R-2.0 on September 10, 2012, 06:32:00 pm
no, not common....
Title: Re: exhaust studs keep braking
Post by: burn_your_money on September 10, 2012, 07:32:05 pm
Depends where you are buying your parts from ::)

NA or TD?
Title: Re: exhaust studs keep braking
Post by: CRSMP5 on September 10, 2012, 07:36:32 pm
warped manifold???
Title: Re: exhaust studs keep braking
Post by: hillfolk'r on September 10, 2012, 07:37:57 pm
whatcha got...a turbo or na?...id try getting the correct nuts and washers and replace all the studs...maybe tq them from the center to outwards also...hey didnt rabbits have a tie strap to hold the exh manifold to the intake manifold also...im just making suggestions cause im not sure if its turbo or na...ive never seen one warped and cause that probl,em tho
Title: Re: exhaust studs keep braking
Post by: mystery3 on September 10, 2012, 10:51:27 pm
They usually only break when you're trying to remove your exhaust manifold, this sounds like it's happening while you're driving which is not common. How are your engine mounts? Are you missing any or all of your exhaust hangers?
Title: Re: exhaust studs keep braking
Post by: jeff115 on September 11, 2012, 06:14:12 pm
its a td, exhaust hangers in place, correct washers in place, vw studs, the manifold is straight, but not stock its an ebay with t3 footprint.  ???this thing is starting to frustrate me. I love the car but changing the studs all the time is getting old, and this time a couple broke off flush with the head. so Im not sure how to get those out?
Title: Re: exhaust studs keep braking
Post by: 745 turbogreasel on September 11, 2012, 06:17:42 pm
http://forums.turbobricks.com/showthread.php?t=221945 <===by me on how I do it.
Title: Re: exhaust studs keep braking
Post by: libbydiesel on September 11, 2012, 06:37:01 pm
So, basically you have a T3 hanging straight off the back of the engine.  Did you add a brace to triangulate it to the block?
Title: Re: exhaust studs keep braking
Post by: jeff115 on September 11, 2012, 06:53:26 pm
that's a great way to get them out. that makes me happy.

yes there is turbo just hanging off the back..... its usually the bottom studs that break though, and I don't think that baby guy is enough to break any thing any way
Title: Re: exhaust studs keep braking
Post by: theman53 on September 11, 2012, 07:06:47 pm
Maybe try not to tighten them too much and not bottom out the studs when installing.
Title: Re: Re: exhaust studs keep braking
Post by: shwak23 on September 11, 2012, 07:18:40 pm
Someone should post pictures of said brace to block. I lose exhaust studs frequently.

Sent from my DROID X2
Title: Re: exhaust studs keep braking
Post by: jeff115 on September 11, 2012, 07:25:51 pm
ill try not bottoming them out, I dont think Im tightening them to tight? they are so tiny that im scared to tighten them to much so alot of the time they come loose too.
Title: Re: exhaust studs keep braking
Post by: theman53 on September 11, 2012, 07:32:34 pm
I am sure, Germans being Germans they probably have a torque spec in the bentley. I regretfully can say I never have used it.
Title: Re: exhaust studs keep braking
Post by: jeff115 on September 11, 2012, 07:43:23 pm
oh good call. ill look fro that spec. but im thinking some 10mm studs- might have to do some clearance work with a die grinder, and a brace from bellow.  if its way over built it usually works right?

thanks for the ideas/advise guys!
Title: Re: exhaust studs keep braking
Post by: hillfolk'r on September 11, 2012, 09:10:12 pm
i wanna say the tq is 18 ft  pounds...or it could be 11...crap i cant remember...someone will post though id bet...
actually you do not wanna use grade 8 fastners...they are too hard and dont expand enough or the same as the manifold and turbo...grade 5 stuff is ok..thas wat i lurned in tek skool n stuff..yea you would think ya want hardened stuff,but just the opposite,ya need flex for heat expansion
Title: Re: exhaust studs keep braking
Post by: fatmobile on September 12, 2012, 12:31:21 am
Got the fatty exhaust washers?
Title: Re: exhaust studs keep braking
Post by: jeff115 on September 12, 2012, 04:04:07 am
Got the fatty exhaust washers?

yes

i wanna say the tq is 18 ft  pounds...or it could be 11...crap i cant remember...someone will post though id bet...
actually you do not wanna use grade 8 fastners...they are too hard and dont expand enough or the same as the manifold and turbo...grade 5 stuff is ok..thas wat i lurned in tek skool n stuff..yea you would think ya want hardened stuff,but just the opposite,ya need flex for heat expansion

never would have thought that.
Title: Re: exhaust studs keep braking
Post by: Alcaid on September 12, 2012, 06:24:03 am
Kinda offtopic, but what T3 are you running?
Title: Re: exhaust studs keep braking
Post by: theman53 on September 12, 2012, 06:26:50 am
Yeah from what hillforlk'r says is accurate. The Grade 8 are much stronger, but lack stretch. You will get way more clamping force with a Grade 8, but if the tensile of the fastener is 120,000 psi it will usually break past that. Grade 5 on the other hand is lots less tensile at around 80,000 but it will give some before it breaks. It will stretch and deform, where the grade 8 will just call no joy and give it up.

If you still need the bentley spec I will get it later if you ask.
Title: Re: exhaust studs keep braking
Post by: jeff115 on September 12, 2012, 06:58:06 pm

Probably wont need the torque specs I stopped at oreily's today and got some 3/8-16 header bolts so hopefully that helps.



Kinda offtopic, but what T3 are you running?

I have run several so far I had a t3to4e from ebay and it sucked. pretty close to the stock t3, but a little bit more laggy. then I had an ebay gt15, witch was left on for the longest because it worked good. drove it for about a month @26 psi still running strong but I wanted to try something else so now I have an ebay gt28rs. hopefully ill have the manifold all sorted out to see how it works this weekend.

the first two ebay turbos I used because I had them...
they didnt leak oil or blow up like I allways here and I pushed the gt15 pretty hard in bad conditions. so I have faith in them. well see how this new one works.
specs are
compressor                 turbine
inducer   54.13mm   inducer   52.00mm
exducer   70.00mm   exducer   45.00mm
Title: Re: exhaust studs keep braking
Post by: R.O.R-2.0 on September 12, 2012, 08:42:10 pm
please dont thread your head for 3/8-16 bolts!

bolts are worse than studs..
Title: Re: exhaust studs keep braking
Post by: hillfolk'r on September 12, 2012, 09:03:46 pm
yea stick with the studs fer sur...just like head studs,they are better than bolts,sothe same applies for the exhaust(or most any application)...even though i graduated from tech school in 97,there isnt a day that goes by im referring  back to what i got learned :)
still gettin learned every day too!
not like you would have to but repeated removal/install of" bolts" would start to wear out the head.
Title: Re: exhaust studs keep braking
Post by: TurboJ on September 13, 2012, 08:22:11 am
Here's a pic of turbo braces:

http://aki76.kuvat.fi/kuvat/vento+TTSI/09042012027.jpg

Aki's work once again.
Ball bearings work great as they allow small margin of movement - will not cause breaking of brace joints.
Title: Re: exhaust studs keep braking
Post by: R.O.R-2.0 on September 13, 2012, 12:11:41 pm
yea stick with the studs fer sur...just like head studs,they are better than bolts,sothe same applies for the exhaust(or most any application)...even though i graduated from tech school in 97,there isnt a day that goes by im referring  back to what i got learned :)
still gettin learned every day too!
not like you would have to but repeated removal/install of" bolts" would start to wear out the head.

yea, the head is REALLY SOFT aluminum..

the bolts are REALLY HARD steel..

the steel wins every time..

nothing like taking a header bolt out, and finding a coil of aluminum wrapped around the threads, that USED TO BE the threads from the head..