I've recently developed a rather significant boost leak (broke off the two lower studs connecting the secondary turbo to the exhaust manifold) and am in need of the stats of all the studs connecting the turbo's to the exhaust manifold. I was thinking of buying all new studs from ARP since that's kind of their forte and the stock ones just weren't cutting it.

Anybody able to help???

 

If I remember correctly, there are 5 each 10mm studs, 2 each 10mm bolts, and one smaller size which I don't remember right now (maybe 8mm). These are all shaft diameters.

Jeff

 

Both the 10s and the 8mm stud are 1.25 pitch. Seeing they are non-magnetic, would seem to support the contention that they are inconel. Doubt getting alternative fasteners from ARP/SPS, etc, would prove to be the cure all. Maybe a bit of nickel based anti-seize on assembly may reduce the breakages.

 

Hey Billyboy, do you know the lengths as well?

I too am looking for replacements. The previous owner replaced all the studs with bolts. They typically only stay tight for no more than 3000 miles. A real pain! I guess studs+nuts handle the thermal expansions better than bolts.

-Lloyd

 

Good point billyboy.

Thanks all for the info!

 

Get the OEM units - there is no reason to go aftermarket here.

 

Seems you can't believe everything on the internet....or the label on a near empty box of nuts, doh!

The five 10mm studs are in fact, 1.5 pitch and near enough 40mm long.

The single 8mm stud is 38mm long.

The two bolts through the wastegate housing are 64mm long, 10 x 1.5.

Not sure it would work in the crypt of fire in the sixth circle of the rotary turbocharger, - but has previously on other turbocharged cars exceedingly well - silver plated k-nuts, expensive in metric and extortionate in the high temperature variety.....touch wood, never experienced a seized nut using them.