High Performance gaskets.

[laserspeeddemon]

I never thought about this in the past. But now with my goals being so high (north of 500, hopefully 600 AWHP), I must pay attention to every single little detail.

I went to purchase an exhaust manifold gasket and I saw this message

For a tight seal up to 450 hp, this is the gasket for you.

OEM Mitsubishi 4-piece copper exhaust manifold gasket fits 6 and 7 bolt DSM & Evo 4G63 motors.

http://streettunedmotorsports.com/parts/oem_dsm_evo_copper_exhaust_manifold_gasket.htm

If a 4-piece copper exhaust manifold gasket is insufficient what then shall I use? So I got to thinking about the gaskets along the way. Since I have the GM AIT tapped directly into the JMF Manifold, I don't want the engine heat to corrupt the tempetature reading so I thought to use a heat barrier gasket, but I don't know if they will hold up to the amount pressure I want to push out. But then again in some cases I just don't have a choice. There is no upgrade for the throttle body gasket. And what about the turbo inlet and oulet gaskets? I've seen thick plates used as gaskets before. Is this enough?

Anyone care to help me answer some of the questions?

 

[gofer]

There are a lot of opinions out there but if you get both gasket surfaces clean and smooth then these things work amazing. FFWD Connection - Race Injuns That Will Freeze Your Brain

 

[laserspeeddemon]

What about the heat barrier intake manifold gasket?

 

[gofer]

I used a Hondata spacer on my Evo III IM a few years ago and did notice that after the 10 minute drive home I could pop the hood and grab the IM with my bare hand. Those aren't results that you're probably looking for but thats been my experience running one. I currently use the OE gasket on my SMIM and I definitely can't grab it after a 10 minute drive, but then again the sheet metal might absorb heat differently than the cast Evo III IM I had when I used the spacer.

With all that said, I don't think it could hurt anything.

 

[99gst_racer]

STM: OEM MITSUBISHI 4-PIECE COPPER EXHAUST MANIFOLD GASKET | 90-99 DSM | EVO VIII-IX | MR323654

That's a typo on their site. That's a multi-layer steel gasket, not copper.
But, that is the perfect exhaust manifold gasket, IMO. I don't know of a better one than the 4-layer MLS gasket. That's the only one I'll ever use.

Since I have the GM AIT tapped directly into the JMF Manifold, I don't want the engine heat to corrupt the tempetature reading

Consider moving that sensor to the IC piping (just before the TB) to avoid heat soak issues.

so I thought to use a heat barrier gasket, but I don't know if they will hold up to the amount pressure I want to push out.

I'm not a fan. I've used two of them in the past, and had bad results with both. I didn't notice much of a change in my manifold temperature either, but in all fairness, I never used any measuring device to properly test for temperature change. The ones that used were for a 2G head, and and they seem to have alot less material around the bolt holes and ports (see pic for reference). Mine deformed badly, pushing sections of the gasket into the port area. Maybe the 1G gasket would be less prone to do this? I'm not sure...

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I also had issues with using one with antilag. If your EGR port is still open, you can get high exhaust gas temps coming through the head and they can melt and blow out the barrier gasket. Just something else to consider.
http://www.dsmtuners.com/forums/bolt-tech/332412-anti-lag-magnus-heat-barrier-gasket.html