AusS2000

I've got my turbo off at present and noticed when I was disassembling that two of the turbo to manifold bolts were loose. It's a LoveFab Minime and GT3071R btw.

They are imperial spec bolts so I have no way of measuring them. Does anyone know the specs and the part number I should order from Stage 8?

godmachine

Call 415-479-2776 ask for glen. Basicly you need to measure from the center of the bolt to the pipes . The bolts have a arm that comes off and rest up against the pipes to keep them from backing off.

AusS2000

Surely this is a known value for a GT3071R?

It was more the length, shank diameter and thread spacing I was interesting in.

jwa4378

^Nope. It would be specific to he header / header flange on your setup. I imagine you could use ones that are too big... you just do not want to get the locking bolts where the locking arm is too short to contact the pipe. You can also custom trim the arm down if you get one that is too big... it locks via physical interference with the turbo header piping.

Think about the picture of them logically... The little rotating arm, the one that prevents the bolts from backing out, locks around the nut head, on the back side of the turbo flange, and rests against the header pipe, where it enters the turbo flange.

The distance between the center of the flange bolt holes to the side of the header pipe should be different based on the diameter of piping used, as well as the type of turbo flange used.

IMO, thread spacing/pitch should not matter... as long as the shank length is long enough and the shank diameter can still fit through the flange bolt holes, they should work (provided the interference arm is long enough to contact the header piping).

John

AndyFloyd

good thing my metric 12.9's are not looseining on me cause these sound like a pain trying to find the right size. If the lovefab manifold is anything like mine its gonna be about 25mm deep and a metric 10 x 1.25 thread.

AusS2000

Hmmm, my turbo manifold is threaded. The bolts go through the turbo exhaust flange plate and thread into the manifold. No nuts are required. I used nuts on some but others are inaccessible. The locking mechanism has to work on the head of the bolt and hence against the GT3071R's turbine housing, not the header pipes.

jwa4378

Yeah, mine is too, but you do not need to get bolts that grab the threading... the nut on the other side is what holds the two together... I guess the threads would add additional contact, but would also probably transfer more vibration, with the increased surface contact.

My flange bolt holes are threaded too, but my bolts are a good bit thinner than the holes (I can JUST barely slide the bolt in and out, with it catching on the threads a tad if you don't put it in exactly straight). Large surface washer then Lock washer and then a nice tight nut, and I have not had any issues with mine in 7 months (since install was finished). The nut was tightened again after the first heat cycle. I got a another 1/4-1/3 of a turn out of it after the heat cycle... It really compresses the lock washer more than anything.

John

AusS2000

Ok, so does anyone know what shank/thread bolt is recommended for the exhaust housing of a GT3071R? I'm guessing there is a correct size and that a step below is too loose and step above won't fit.

jwa4378

The exhaust housing can have many different flanges on it. Its the flange threading that you need to know, and that was probably done by LoveFab. I know it was HP Performance that did all the flanges on their housings for my kit...

I believe the only thing specific to the exhaust housing of a GT3071 vs. GT3076 vs. GT3082 is the size of the exhaust housing itself (volume inside the turbine area)... I think they get bigger as they go up, as I think its the exhaust turbine that is changing... it still has the GT30 compressor (I think that is right... it might be reversed).

You need to know what thread pattern is on the flange used by LoveFab. Have you tried giving them a ring?

What style flange is it? T4?

From LoveFab's site:
http://www.lovefab.com/html/s2k_minimeac.html
[QUOTE]Product Features:

* A full 3 inch downpipe can be utilized
* Requires the use of a TiAl 44mm wastegate
* Professionally TIG welded in-house using 100% argon to

chris_barry

Aus,

Can you use studs in the manifold, and use heat proof K nuts ( sometimes called jet nuts) in place of bolts.

My SAAB 9-5 used that setup on the turbo to manifold. The nuts are high tensile material and are slightly oval which provides the locking grip.

I would get some M8 studs and visit a SAAB dealer for some of the nuts.

Chris.