Hi,

I see Inconel Studs are highly recommended, they seem a bit pricey, I was wondering if anybody has any positive experiences with these - Bolt v stud, or anything similar ?

10MM TURBO BOLT Locking Fastener KIT
Item Number: 3904 (4) 10mm-1.50x25mm 6pt DHH. Stage 8 manufacturers the World's Best Active Mechanical Locking systems. Our locking fastener solutions are fail-safe when used and installed as directed. They are removable and reusable and can be visually inspected; if the locking retainer and clip are present With 15mm Head and Stainless Steel Hardware

#3904 10MM TURBO BOLT Locking Fastener KIT-| Stage 8

 

Loosening is not the issue that we are addressing with Inconel.

 

You know what most of us are going to say. We are all going to say go inconel. Either that or Vband.

I'd rather spend the additional $100 and go with a proven setup(TSE). My exhaust manifold nuts haven't budged since installing them.

 

These from Mazda are pretty cheap inconel studs

 

Ooops. Didn't really see the link.

Those bolts "might" be OK. You have two issues:

1. They are heat-resistant SS rather than Inconel. That means they have a Coefficient of Thermal Expansion that is double that of mild steel or iron. Because of that, the joint will get loose as it heats up. I don't know if it will become loose enough to cause an exhaust leak though. But the potential is there. BTW, this CTE property is why heat-resistant SS makes such a great high-heat gasket.

Inconel is specifically engineered to have a CTE nearly identical to mild steel/iron. If you need the joint to have the same tightness at room temp and at high temp, use Inconel.

2. With a bolt, the disassembly thread area is the threaded hole in the manifold itself. You'll usually end up with more thread contact/binding area and they'll be exposed to more consistent and higher heat. With a stud and nut, the threads that you care about are in the nut and the nut will be radiating and conducting to air. It won't trap the heat as much. The bottom line is that you have a better chance of tearing everything apart a year or two later if you are using a stud and nut.

So, what you linked to might work. Inconel studs with Stage 8 nuts is the proven solution though. You stack things in your favor for a little bit more money. And, as Harold pointed out, OEM parts for turbo cars are a great way to get Inconel on a budget.

 

Honestly, the difference in cost versus your car sitting on the side of the road or mid race day with a turbo falling off.....

I wouldn't hesitate, since buying the inconel studs AND fasteners AND thread lock Jiz from trackspeed I have not had a problem.... prior....what a friggin pain in the ***.

 

Cheaper than a single ruined track day:

Trackspeed Engineering M10 Inconel Stud Kit

 

+1 for inconel studs. Saving a little bit of coin is not worth the headaches/wasted track fees/tow truck/etc that you risk.

-Ryan

 

Cool, thanks, good option to consider. I was looking at the washers that are used with these - they are over $6 a washer - is there something special about them I need to consider ?

 

Nissan also has an oem inconel stud that you can find a part number from if you search around the forum