Turbo to manifold studs: 300ZX Inconel or 304SS threaded rod (Hey, Leafy, over here)
#21
Turns out that various FD's employ at least 3 different studs around the turbo system.
This one runs about $18. I believe this is the 93/94 manifold to turbo stud based on this guide. (9YA9-21-008 or NF01-13-708A or NF0113708A)
This one is a '95 specific part that is a little longer than the others. This is the part that I called the dealerships about. $7-$8. My information for this part comes from this installation guide (quoted below). (9YA9-21-003)
The downpipe stud appears to be here based on this parts diagram. $6. (9YA9-01-002)
There's also an 8 mm stud, too. I don't know which are Inconel, but judging by the prices, it's probably the expensive ones.
Thankfully, my mechanic friend says he fixed my manifold. 300ZX studs here I come. Woo woo!
This one runs about $18. I believe this is the 93/94 manifold to turbo stud based on this guide. (9YA9-21-008 or NF01-13-708A or NF0113708A)
This one is a '95 specific part that is a little longer than the others. This is the part that I called the dealerships about. $7-$8. My information for this part comes from this installation guide (quoted below). (9YA9-21-003)
On a 95 FD (like mine), the parts microfiche calls out p/n 9YA9-21-003 for the studs and p/n 9YB1-01-001 for the locknuts. These locknuts are about 1/4" longer then the short locknuts for the 93/94s. The studs in the 95 are also longer to accommodate the long nut. When I went to the dealer to get these parts, they gave me the short studs and the long nuts. The dealer said the p/n 9YA9-21-003 studs was "invalid" and not an available part, so the only alternative (per dealer) was the 93/94 stud.
One list member responded to my original post and kept saying that the long nuts work fine on the "short" studs. So, after more research I discovered that the studs used for the downpipe on the turbo are the just a hair shorter than the unavailable long studs for the 95 FD. I measured the short NF01-13-708A stud, and sure enough they are about 1/4" shorter that the downpipe stud, which in turn is only about 2 mm shorter than the long stud (are you confused yet?).
So, the bottom line is -- if you are going to use the long locknuts, then use the studs for the downpipe instead of the called out NF01-13-708A stud. The long nut on the NF01 *will not engage the locking feature of the nut*.
Here's another bonus -- the DP stud is $6 compared to the NF01 stud at $15 each. Can't beat that.
One list member responded to my original post and kept saying that the long nuts work fine on the "short" studs. So, after more research I discovered that the studs used for the downpipe on the turbo are the just a hair shorter than the unavailable long studs for the 95 FD. I measured the short NF01-13-708A stud, and sure enough they are about 1/4" shorter that the downpipe stud, which in turn is only about 2 mm shorter than the long stud (are you confused yet?).
So, the bottom line is -- if you are going to use the long locknuts, then use the studs for the downpipe instead of the called out NF01-13-708A stud. The long nut on the NF01 *will not engage the locking feature of the nut*.
Here's another bonus -- the DP stud is $6 compared to the NF01 stud at $15 each. Can't beat that.
There's also an 8 mm stud, too. I don't know which are Inconel, but judging by the prices, it's probably the expensive ones.
Thankfully, my mechanic friend says he fixed my manifold. 300ZX studs here I come. Woo woo!
Last edited by Wowbagger the I.P.; 01-14-2014 at 08:07 PM. Reason: Added part numbers
#25
Removing the remains of a broken stud from a manifold requires extraordinary skill, bravery, experience, knowledge, ability, passion, shrewdness, persistance, forethought, cunning, a guardian angel, prayers, or................ a TIG welder.
Soak the area with blaster, place a nut (two sizes bigger than the stud) over the hole with the stud, reach down through the nut and weld the stud remains to the inside of the nut. Build up the end of the stud if needed before putting the nut in place.
While hot, rap lightly all around the nut. Sideways, also. Put a wrench on the nut and try to wiggle it back and forth. Don't get too hasty. Expand the wiggle slowly, add more blaster, and all of a sudden it will unwind and fall out.
If it breaks off, you loused up either the weld or your patience. Either way, do it over again.
If its an FM manifold, I'll fix a broken stud at no charge. Its just a means of having fun.
corky
Soak the area with blaster, place a nut (two sizes bigger than the stud) over the hole with the stud, reach down through the nut and weld the stud remains to the inside of the nut. Build up the end of the stud if needed before putting the nut in place.
While hot, rap lightly all around the nut. Sideways, also. Put a wrench on the nut and try to wiggle it back and forth. Don't get too hasty. Expand the wiggle slowly, add more blaster, and all of a sudden it will unwind and fall out.
If it breaks off, you loused up either the weld or your patience. Either way, do it over again.
If its an FM manifold, I'll fix a broken stud at no charge. Its just a means of having fun.
corky
#28
B) The proportions aren't optimized for a Miata application.
C) I know TSE rolled the threads for strength, but I don't know that about the OEM bits.
D) Finding the right part can be somewhat of a guessing game - some may want to pay for the confidence that it will certainly work and that they won't have to mess with it.
E) Money!
etc.
#29
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One reason is time. Back in 2009 I don't think we knew that the RX-7 and Nissian ones were Inconel. If we did I am sure Savington and Hustler and a few others would have tried them to see if they stretched or not. On the other hand I do believe that TSE can charge the premium that they do because as far as I know they are the only company that has proven on track that their bolts do not stretch. When some other company puts up back to back testing showing that they have under SM lap times and are stretching stock studs, then using the RX-7 or Nissian studs and shows them not stretching at the same lap times I will start saying those are acceptable solutions. Until then the only Inconel studs that I will personally recommend will be the TSE studs.
#30
One reason is time. Back in 2009 I don't think we knew that the RX-7 and Nissian ones were Inconel. If we did I am sure Savington and Hustler and a few others would have tried them to see if they stretched or not. On the other hand I do believe that TSE can charge the premium that they do because as far as I know they are the only company that has proven on track that their bolts do not stretch. When some other company puts up back to back testing showing that they have under SM lap times and are stretching stock studs, then using the RX-7 or Nissian studs and shows them not stretching at the same lap times I will start saying those are acceptable solutions. Until then the only Inconel studs that I will personally recommend will be the TSE studs.
#31
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No doubt it depends on what you are doing with the car. I was simply responding to why TSE developed their studs. For street cars I think standard grade 8 hardware works fine. If you want to goto the RX-7 or Nissian studs then they should be more then fine.
#34
I respectfully disagree, at least if you put some real miles on the car. Even street driving will creep mild steel. After 20K, I had 1 broken and the other three loose. Safety wire kept it all together, but the turbo wasn't tight.
I happily sent money to Andrew. I started tracking after the improved studs were in place.
I happily sent money to Andrew. I started tracking after the improved studs were in place.
#37
I stretched my m10 grade 8 studs & hardware within a few months of auto crossing and street driving too. It's a waste of time to go through the hassle of running inferior hardware for only a few months to then have to deal with pulling it and replacing it with good stuff. If you can't afford the TSE stuff off the bat then get the OEM inconel.
#39
SS is much more resistant to heat than mild steel. Often used on jet engine applications. The only issue with SS vs. Inconel is that the thermal expansion coefficient for stainless is a mismatch for mild steel/cast iron (so it loses a bit of clamp force as it heats up). Inconel is a good match.
TL;DR your SS studs should be OK.
TL;DR your SS studs should be OK.