Where to go from here...
 

Go to a track day Monday, noticed by 3rd session car made 12psi instead of 14 and feeling a bit sluggish.
noticed some soot between runners 1 and 2 on the head.
removed the manifold today. Not really sure where to go from here. I've already milled it once and put extra relief cuts into the manifold and used high temp copper RTV on it with a gasket.
Should I make my own copper gasket or buy some sort of thick gasket for it?
This is an early ARTech manifold with downpipe. I would really love if I could keep the downpipe since it's a beautiful divorced wastegate style but I am worried a FM manifold wouldn't clearance it.
Looking for some advice.

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High temp rtv wont do anything with a turbo manifold. Are the relief cuts closed up?

The middle relief cut looks to have closed up. The rest still have some space. You think a thick copper gasket could help me out? I ran copper on my WRX for a few years with no issues, just sucks that they are pretty much a single use thing.

It might be worth a shot. On my 1.6 manifold I had to surface it twice and cut relief cuts twice. It was kind of like it was relieving stress from being welded. And needed to cycle once or twice. I would open up the relief cuts and surface it one more time before giving up.

Alright. I'll give it a go. I kind of want to try a thicker gasket material outside of the MLS. Did you just keep buying new gaskets or reusing your old ones?

Probably new ones. Don't remember at this point.

It sounds pretty similar to what hustler et al have been through and worked out years ago. Probably why TSE has a cast manifold.

It looks like it from your pictures but the 3 cuts can be in between the runners so they're all separate by about the thickness of a hacksaw blade. Then surface it, but just enough with a belt sander to give a smooth flat finish. You can try some heat treatment for stress relief on the manifold but turbo manifolds go through pretty extreme heat cycles during use and that might be a waste.

I think the multi layer steel gaskets are best for this but you could try copper especially if everything is flat. I don't know the temperature of the cylinder head around the port area vs exhaust gas temp but my gut feeling is that room temp vulcanized rubber aka copper RTV is no good for exhaust parts. Would you put a rubber o ring there and feel good about it? I've done it myself but not on a turbo manifold.

You could try some stronger exhaust studs although people don't do that too much? You're also going into aluminum so going too tight there might not be the best and bolts can be easier than studs if you need the clearance sometimes. Then Stage 8 locking tabs so they don't come loose. But I'm at a loss for the best torque for these. I think you want them as tight as you can get them, even after several rounds or while still hot, but if the studs are stretching a lot under heat then it's probably going to start leaking again anyway.

I cut between all the runners with my band saw. Only the middle one has closed. I have already machined it once and the flange is starting to get a bit thin. The copper RTV was a recommendation from a late model dirt racer. He used it on his motor, albeit it's not turbo but, it is over 700hp and sees some pretty intense heat. I am sure he doesn't have the back pressure I have, though.

I'm going to go to my local metals warehouse and see if they have some copper sheet. If it doesn't work then I'll keep on the lookout for an FM manifold and hope the downpipe I have clears.

You mentioned that you've machined it down already, and it's getting thin. This is a bit of a long shot, but have you checked to see whether the unthreaded portion of the exhaust studs in that area are standing proud enough to prevent full clam up?

I think you bring up a great point. That is another reason I wanted to try a thicker gasket. Maybe double up and put washers between the stud and the nut?

I also found a group buy from a guy on MX5nutz across the pond. His manifold puts the turbo closer to the current location than any other manifold I have found, yet. I am going to test fit it up to see if my exhaust and intercooler piping still fit and if they do I will probably just run it. If not then I am going to band-aid this manifold to get a year or two more out of it. I don't want to sink any more money into this kit as I would like to go ecotec in the future if I stick with a Miata chassis.

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I wonder how they came up with that design.

Oh. That looks just like my track speed manifold.

Awkward.

I wonder if the ME221 crew is behind this one too...

I think it's similar to your manifold Sav but it's not made from near the same strength of material. I also think the final product may look a touch different than this rendering as the runners for 1 and 4 looks almost equal length in some renderings. I'll have a video of it on my YouTube page once I acquire it and install it.

Some of the buzz words used in the ad for the manifold. "Made from spheroidal graphite NI-Resist alloy, same as turbocharger housings and or VW/Nissan turbo exhaust manifolds".

https://www.youtube.com/channel/UCQK...i9pGarSnjLY_cQ