Turbo & Manifold Hardware Discussion

[ixfxi]

I wanted to start a thread that has to do with turbo components and hardware. It seems there is a lot of confusion & mixed opinions in regards to the following:

1) Turbo Gasket. The two most problematic gaskets are:
- Turbo to Exhaust Manifold
- Turbo Outlet Housing

A well known & respected company in the industry suggested NOT to use a gasket between the Turbo & Exhaust Manifold. I thought that was odd. Their belief was two fold:
1) Keep the heat transfer even between turbo & manifold. No gasket = better heat transfer
2) The manifold must be (machined) flat to ensure proper seal.

NISSAN obviously uses a gasket with locking hardware (clips), which brings me to my next issue:

2) Secure Turbo Hardware. Again, same problem areas:
- Turbo to Exhaust Manifold
- Turbo Outlet Housing

I have read so many weird methods that people have discussed over the years on various different forums. Lets start with what I think are the best ways:
1) NISSAN's method is use high-grade (OEM = Inconel?) fasteners. No one has been able to confirm that the OEM hardware is inconel, but I think we all can agree that the OEM hardware is indeed up to the job. So if I am correct, NISSAN uses Inconel studs & nuts, then secures the hardware with the locking tab/clips we all know. I personally hammer the tabs around the nuts to make damn sure that the nut has no way of rotating.

2) Tack welding the hardware. Some people have simply tacked the nuts to the studs, and that keeps the nut from spinning obviously. This method sounds good and is easily serviceable, at the expense of replacing your studs/nuts if/when you ever decide to remove and/or replace the turbo. Not a big deal if you ask me.

3) Safety wire. I purchased some nice inconel safety wire but ran into a big problem when it came to locating drilled nuts. Hardware that has been drilled for safety wire is typically found in aerospace and acquiring this hardware does not seem easy, metric especially. With that said, the only solution I found was to take a batch of nuts to the machine shop and have them drilled with holes for the safety wire. I purchased a jig online that would allow me to do this on my drill press, but the OEM hardware is just impossible to drill through no matter what grade of drill but I was to use.

4) WELD the turbo to the manifold. This does not seem like a wise choice for various reasons. Anyone familiar with welding understands that cast iron is not an ideal metal to weld. The results are questionable and I wouldnt be surprised if the components are susceptible to cracking.

5) Fancy shit such as Nord Lock nuts, Stage 8 fasteners, or Resbond high temp thread locker.

To be honest, the first 3 methods seem to be the best. Either use OEM hardware, or if thats insufficient then switch to safety wire or fucking tack that shit down.

LAST item has to do with the EGT. Not everyone cares about gauges or monitoring their temps, but I do. With that said, where and how are people mounting their EGT?

1) Before the turbo (ie: turbo inlet temp) means that you must drill into your cast iron manifold.

2) After the turbo (ie: turbo outlet temp) means that you must install the probe into the Turbo Outlet Housing.

Obviously, if you have a tubular type manifold then welding a provision on there is much easier. But if you're using the OEM cast iron manifold, then obviously welding is not an option as you risk cracking. You would have to find an area where you can drill and tap the exhaust manifold, or, you would have to install it after the turbo.

Feel free to chime in. Except you, Kingtalon.. I dont want to read a 10-page dissertation on how we need a fucking clean room or any of that bullshit. :-)