I don't think the 3mm seals are designed for longevity. I am sticking to stock Mazda seals on my own engine (also street ported), but you'd need to replace your rotors to go back to 2mm seals. The 3mm seals are meant for high boost applications, but they might be overkill if you're running a close-to-stock sequential turbo setup. I have seen some low-mileage rotor housings with wear marks from running aftermarket seals.

 

plently of cars running 800+ on 2mm and 3mm seals.

In my totally unexperienced opinion, going to 3mm should only be done if your rotor slots are out of tolerance for 2mm seals. But at the same time Goopy sell oversized 2mm seals to fill that gap. Makes me wonder why more apex seal companies dont offer an oversized 2mm.....

 

3mm seals do not offer enough of a cushion to warrant using them unless your rotor grooves are totally fucked. If they're just a little out of spec I'd suggest Goopy oversized seals. I haven't used them personally but I've heard nothing but good things. Other than an engine I slapped together as an engine dyno test mule with Atkins seals I try to only use stock Mazda 2mm seals or ceramics.

 

I think I found a solution to my question. I'm going to take the rotors from my bridgeport engine and use them in the rebuilt streetport from Rotorsports Racing so I can use 2mm 2-pc Mazda seals instead of the 3mm ones he has in the engine. The goal is 400WHP max running a BW S300SX-S 8380 turbo.

 

That's going to be perfect for you, Anthony!