Update and question.

[GN FAN]

as an update to my previous post........I finally got my car apart and everything cleaned up and waiting on my new parts. my question is there was no gasket on my turbo to exhaust manifold and no gasket on the exhaust manifold to the block nor on the crossover. i had no leaks but i'm not sure how that was possible. should i use gaskets and if so which ones.

as always, thank you for the insight.

 

[TurboDave]

As produced from the factory, there were no gaskets in those positions. You should at all costs avoid using gaskets at the turbo/manifold and manifold/head points. Using gaskets will certainly cause warpage of the flanges involved when the bolts are torqued and the heat cycles start.
Crossover pipes are donut style mounts that don't use gaskets either.

 

[GN FAN]

thank you sir! i won't bother with them at all then. just out of curiosity....why is that? any other car i've ever had always has gaskets and most vendors have the metal replacement gaskets for the manifold/head location.

 

[TurboDave]

Probably because, it being a turbo charged motor, temparatures in the above mentioned areas are exceedingly higher than a N/A (normally aspirated) motor. EGT's at the header and turbo inlet can and often do exceed 1450°F and as high as 1650° in racing situations. Most gaskets can't hold up to that kind of abuse, especeally when a lot of heat cycling is taking place.
I've seen several cases where even a solid copper gasket at the turbine housing will eventually "blow out"
Good smooth/true metal to metal contact still can't be beat.

 

[Boost231]

sometime you have to use a gasket in the turbo to header area due to the flange not being flat. RJC sales a gasket that works great in this area. if you can get away with no using a gasket thats the way to go but sometimes you dont have a choice.

 

[GN FAN]

i guess we'll see what happens when i get the new used turbo on there....waiting on a new exhaust manifold for now.

 

[Boost231]

well if you do remove the passenger side manifold you cant get it cut so its flat before you reinstall it.