Lot of places sell it. It's called fire sleeve. Search on eBay.

An update...
The engine has a lot of boost creep due to the position and size of the waste gate on the manifold, so I have ordered a much larger waste gate, and will ensure that the inlet port is angled well on the manifold to maximise flow. Once that has been done, it will be able to experience some proper power runs.
We saw 165kW at 4400rpm at 25psi with no fine tuning at all, so it is looking like it will be a healthy number at the end.


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What size are you using? I had that issue with mine but it was the spring pressure more so than the wastegate size.

38mm. I think the primary cause of the issue is exhaust manifold design. I have a 17psi spring in the waste gate.

A 50 would be better and a softer spring. I'm no specialist but that was my experience when I had the GTX3071r on my 3SGTE. It was about the same spring rate but was constantly overboosting to 2bar+ which what I was not looking for. 

This is why it boost creeps - bad manifold design. 
The gas has to turn more than 90 degrees to exit out of the waste gate. 
If the angle was a lot less, it would probably be OK.
 

Can you run two wastegates or a single 50mm? Not sure that would be an issue.

Space is an issue, though I think we can use a 50mm with a better designed entry port from the manifold collector.

Another update. The Haltech is dead and I will be taking it back for a warranty claim tomorrow.
The internal MAP sensor reports 20psi when the ECU is powered up. This is without the engine running.
Oh well.... #becauseracecar

Haltech fixed the ecu yesterday under warranty. Apparently it wasn't assembled properly and there was stress on the solder joints of the map sensor, which eventually cracked the joints. It's now running again and it is ready to take to the exhaust shop on Saturday to get the manifold modified to suit a larger waste gate. After that, it will go back onto the dyno for the final tune. I hope that will be the end of the niggling issues. I'm started to get excited now. It's going to be so much better than before!

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