Stock Twin Turbo Hardware
 

Been scouring the internet and forums for somewhere to buy basic Iconel hardware. I believe that the factory bolts that hold the stock turbo center collectors together are, or should be, Iconel (See Picture).
https://cimg0.ibsrv.net/gimg/www.rx7...e7ab275d97.png


I had one break while taking the assembly apart to port the wastegate and need to replace at least the one (m8 x 1.25 thread ~20mm long). Does anyone have a source for buying basic Iconel bolts? The only places I can find are industrial suppliers with like 20,000 piece minimum buys and everything else is either studs or shorter CHRA bolts for single turbos. Unless someone has had success other than Iconel but I don't think that is the best idea in this area, I don't want to blow one of these gaskets after stainless steel bolts stretch because they are not replaceable without buying another turbo assembly.

If you're in a bind and definitely want to use inconel you could possibly order the inconel studs from Mazda (they're still available) and throw a nut on it instead of using a bolt.

I think based on availability of this hardware I am going to roll the dice on a grade 10 black oxide bolt. I will report back if I have any issues.

I am hoping that since the turbo assembly is held by studs to the exhaust manifold that these bolts don't see much load.

But yes I think the stud / Nut idea would also work.

Load - not so much. High heat, very much so. The heat changes the material properties, and the wrong hardware will certainly fail. This is the reason those studs are made of the stuff they are. Don't cheap-out here. Just call Ray and get the right hardware.

If that isn’t a part that Mazda stocks separately you could always post a wanted ad for a used one. Lots of people have bad sets of turbos laying around

The twins were manufactured and assembled as a unit from Hitachi, not Mazda. The hardware you are looking for does not have a Mazda part number.

I would recommend finding failed/cracked twins in the classified. I personally have a cracked ‘93 N3A1 set in the garage...

And right there is the issue, not something that can be purchased from Ray unfortunately.

Called around basically every distributor said the same thing "You won't find an Inconel metric hex head bolt in small quantities" at least not in the U.S. Nakd is probably right, only good option is to scavenge off broken twins. Risk of blowing the gasket is just too high to not get the correct bolt. I don't think one of the studs + nut would work as there isn't much room once all assembled.

Thanks for bouncing ideas here.

... if you need a bolt let me know ...
I would bet half the running FD’s these days have functioning sequential twins, they are worth your time and effort.