Woohoo! 4 bolts sheared off in manifold!
 

Attachment 211740

2 of them sheared off on their own from normal driving. The other 2 sheared off pulling the turbo to fix the first 2 bolts. They were all class 10.9 stainless bolts. WHY??!
It looks like I'm going to drill it all out to 10 mm bolts to hopefully keep this from happening.

too much stress from engine moving against exhaust and vice versa. got a flex section in the DP?

No flex section. Stupid downpipe had been modified to include a flex section and cat in one piece. I had a test pipe made and that took the place of the cat and flex section. Guess I'll get one welded in.

Any Greddy people have their turbo to manifold bolts up sized to 10 mm? I was thinking about that but clearance could be an issue.

you should port match the manifold when you pull it to fix :)

Will stiffer motor mounts help with this problem?

Port match... Yummy

exact problem i have right now. i sent in my manifold to get fixed, cost a pretty penny just to ship the damn thing. it will be upgraded to 10mm studs and hopefully the problem will be dealt with for good.

Aint no way I'm gonna ship my manifold off and pay someone to do something I can do myself.

true, but i dont exactly trust myself drilling cast iron and hardened steel, especially with removing broken studs that are deep inside the manifold. easy-outs dont work so "easy" on hardened metal.

Good luck getting those out. Take it to an engine builder/machine shop and have them drill them out and tap for 3/8". 3/8" exhaust stud is pretty easy to locate, 10mm not so much.

I did this on mine when the exact same thing happened, was all shinny and happy after that.

MMR mounts here, no flex, no problems

I've got a set of Mazdacomp mounts in the garage that have been waiting to go in for a very long time. Hmm, the coolant reroute I picked up at Begi last weekend shall go in too. :)

My attempts at removing the bolts have not been very successful. Trying again tomorrow.

like he said, good luck. if you use an easy out and get that broken on that, youre in for a treat.

Stainless steel is your problem. Dissimilar metals FTL. Use high grade steel next time and go bigger as already said. If it was me, I'd use castled nuts too and drill the studs so you can cotter pin the nuts.

You know, the bolts gained a white flaky crust after a couple heat cycles but I don't remember if they were stainless or not now that I think about it. All I know for sure is they were class 10.9.

Haha, turbo mounted with cotter pinned nuts, not even god could make it fall off.

Notice in the picture, the relief cuts I made with a hack saw were fusing back together. They tightened down on the head studs and made pulling the manifold an absolute PITA. I ended up hitting the manifold with a sledgehammer up and down dozens of times to get it off.

Sounds like you used galvanized bolts then. That's a no no too.

Not even with both hands.

Bryce,don't waste your time trying to get them out on your own,take the manifold to a engine builder/machine shop and pay them to do it.

Yeah come Monday that's what's happening.

Pssh. Go to a good hardware store or the likes and get a set of left hand drill bits, center punch, and a hammer. Center punch the broken stud, drill a pilot, and slowly drill larger and larger. When you get to about the largest you can drill, as your drilling, you 'carefully' bury the bit making it hang in the metal. The bit breaks or the stud spins out. Usually works for me. If it breaks you can chip it out of the way and just drill it out completely and put helicoils back in. Helicoils are stronger anyways.

helicoils are the stuff that dreams are made of, but why not just convert to 10mm studs?

I've never seen a helicoil before. I'll be upgrading to 3/8" studs if anything, much easier to find around here. I'm taking at look at the M-tuned manifold and contemplating maybe, just maybe, I should ditch this stuff and upgrade the turbo.


A replacement mani from Greddy supposedly only costs 150 but that could take awhile to get here and god forbid I have to throw the stock exhaust header on and go naturally aspirated for awhile.

Port Matching?

It's where you do a little machining on the manifold and gasket so it matches the exhaust ports on the head exactly for smoother flow.

I'm going back to NA till I fall on a little more cash. Having the intercooler in the intake is definitely gonna add 20 horsepower to the wheels! :giggle:

Well, I converted back to naturally aspirated. Still running megasquirt and a 2.5" enthuza catback and OOOHHHH MYYYYYY GOOOOOOOD ITS SLOOOOOOOOOOOOOOOOOOOOOOOOW.

The 3.9 rear end killed all the acceleration it had N/A.

I'm just gonna drop a couple big ones on the ETD tubular manifold.

If you do not trust yourself, any machine shop will pull those studs for like 50 bucks. In addition, I would recommend dropping some coin on a damn flex section.

you can see from the residue left on the flange that the turbine inlet is larger than the port on the manifold itself. Opening the hole up to match the turbine inlet might be good for a point or two of efficiency.

did you get them done?

Did not miss much at the ball game. Backie gave up to grand slams :(

Well not yet, needed the car drivable today as I'm head down to help a certain someone work on his car.

Must be a GOOD friend. I couldn't ever imagine going back to N/A...even with a V8:giggle:!