So yesterday i come home to see a box with my o2 housing which i purchased from Buschur racing. So i took that out of the box and also pulled out the Buschur 2.5 DP and was trying make sure they matched up, and it will not. Does the ebay o2 housing that Bushur sells not work work with the 2.5" dp? I looked at the site again and it does not state that it has to be the 3". Below are pictures. Any help would be appreciated. Thanks.

DP Connection


o2 and DP


Another view

 

I am pretty sure you need to put the donut gasket back on and it should seal from that alone. I would double check though.

 

They don't mate flush on the flanges. The outlet of the o2 housing should extend into the opening of the DP - that connection should be perfect, but the flanges don't touch. It will look like your last pic after it's installed - that's how it looks on mine.

Revmoto, the donut gasket is for 3" flange openings, so it's not used on the BR DP.

 

Strange, I had the same issue with my 3” DP. I emailed Jarrod and he told me they should slip together and then instructed me to grind a little bit of the coating off the O2 housing until they slip together. After doing so my two flanges fit flush and the DP has no clearance issues.

 

Maybe you have a different definition of "flush"? That pic shows they are not flush but still mated nicely unless that first pic is not the same as the 2nd pic.

 

I think the flush fit is shown in the second pic when the o2 is bolted down...

 

But if you look at the o2, there's a lip that does not go into the DP, so the two parts are always separated by at least that much. The part that inserts into the BR DP is thinner than that outer lip that keeps the flanges from touching.

 

I see what you mean. Does the O2 housing supposed to have that lip?

 

I understand the definition of flush but I see where my description is confusing. The first ½”, or so, of the 02 housing lip should slide into the DP until the DP flange is flush with the first step (or flange) of the O2 housing, leaving a small space between the DP flange and the O2 housing “bolt” flange.

Regardless, when installed it should not look like my first picture or the last picture in the first post, that lip has to slide into the downpipe.

Warr, if your DP installed looks like the last pic it may be wrong.

 

It looks like you may need to grind away some of the material on the downpipe flange. I can tell you that the Buschur exhaust I had sat flush into the Ebay O2. I highly doubt the .002" of coating would cause your problems. Although I did have a BR 3" system, although the DP flange was somewhere around 2.5".

On a car we installed our coated O2 housing with the Buschur DP we had to grind the flange down a bit so it was a but wider. The Buschur exhaust does not use a gasket of any kind. If you are really concerned you can get some copper RTV and use this as a seal. I installed with and without RTV and never really noticed a difference.

Good luck!

 

I had to reduce the area in the DP flange in order to fit the coated O2. 15 minute job with a drill and a $3.99 rotary stone from Sears.

 

umm has there ever been a Buschur part (DSM or EVO) that hasn't required it to be modified to fit somewhat correctly? Some things never change