Busher's 3” downpipe fitment
 

I bought a used Busher 3” downpipe that was supposed to my application. When I opened the box, I noticed that the flange didn’t have the beveled edge that mates to the doughnut gasket. From looking at it, it seems that it was either designed to fit without the doughnut or it’s for a completely different application. Can someone confirm either or? Thanks.

http://i114.photobucket.com/albums/n...g?t=1256776358


http://i114.photobucket.com/albums/n...g?t=1256776407

No donut.

from what i remeber the br dp , does not use the factory donut gasket , it uses a br gasket thats provided when u buy a br downpipe ,

btw , i should have one laying around id have to look

p.s get that white junk out of that pipe man :lol: ur goin to clogg the cat

The buschur downpipes are not designed to use a donut style gasket. You can either use a round flat exhaust gasket or high temp copper rtv.

My friend is a tech for Ford/Mazda, when I had the Buschur downpipe he got a 2.5" round copper gasket that the mazda's used. I tried it out and it worked perfectly with no leaks. Its hard to tell from the picture below but its actually a crush style gasket.

Middle gasket:
http://www.neiu.edu/~asaakian/Exhaus...ush/Gasket.jpg

It doesn't use any gasket. Take the donut off and install it. It seals just fine without those junky gaskets

sorry to kind of hijack your thread but I have a somewhat related question: how about the hardware? i.e what bolts do we use when installing a BR DP? the oem spring kind?

Yep, just reuse the spring bolts.

I use to have one back in the day and mine leaked w no gasket.. thats the way its designed though

My BR down pipe was installed with no gasket. It does not leak at all.

ditto

Did you try it with a gasket afterwards? Is this the kind that will work with it; http://www.lancershop.com/customer/p...productid=588?

So did you replace the buschur dp with another brand?

i had the same question as the op. thanks for all the replies.
however i noticed that the spring bolts and the donut allowed for the engine and exhaust to move. The br downpipe doesnt have a flex pipe on there. does this mean it is ok to have one solid fixture from the O2 housing all the way out back? or are we assuming that the rubber hangars are enough for the engine flex?

bump for any comments

Go to Mazda dealership. Buy the RX8 gasket for the exhaust manifold to catalytic converter connection. Its the middle gasket from the picture I posted a couple posts above.

I used that gasket with my Buschur turbo back exhaust with ZERO leaks. I just got another bushcur trubo back and I will be using that gasket again.