i just bought a buschur 3" turboback used from a local guy. when i was inspecting the exhaust i noticed that on the downpipe flange that bolts to the o2 housing, there was what seemed to be some sort of black sealant on it. i know when installing the downpipe, you have to remove the factory donut gasket, but my question is, are you supposed to put something on the flange to seal it? if not, should i remove that stuff and polish up to make a nice seal? thanks.

 

um yes you should have a gasket there, we used a megan racing 3" and the factory donut gasket

 

thats not what i'm asking. i have to remove the factory donut gasket to put this downpipe on. my question is do you need to put some kind of new one on or something like it?

 

Someone may correct me, but I seem to recall that I used no gasket, and that's what BUschur says. No problems at all with mine. Then BR DP is unique this way.

 

Buschur downpipe does not require a gasket. Yes, you must remove the factory donut gasket. Try to salvage it as best as possible -- its like 15$ @ mitsu.

 

cool. then i'm gonna polish that flange so its nice and flat and makes a good seal

 

You don't need a gasket and you need to remove that factory gasket.

 

Don't bother polishing it, that isn't what seals it. The factory o2 housing has a lip that protrudes into the downpipe about a 1/2". This is what keeps it sealed. You also do not have to get crazy torqueing the bolts. IF you overtighten them it will just warp the downpipe flange. As I said, the lip is what seals the downpipe.

Take care,

David Buschur
www.buschurracing.com