Here are a few pics of my Buschur downpipe. The first pic is before I "trimmed" the fin on the diff. The second two pics are from after I trimmed the fin.

I've been unable to get Buschur to make it right. Dave initally told me to "hit the fin with with a hammer to knock it off." I used a Dremel to gently trim the fin. I've told Dave about it numerous times. He even took me back in the shop and showed me the jig that they use to weld them up.

The big question is... what should I do? It's likely causing false knock... ya think?

 

a bit off topic.... but when did buschur start using flex joints in his DP?

 

Thats what I was wondering

 

I bought the pipe in late 2004. It wasn't anything that they did especially for me. They were offering it at the time. I'm not sure that you can still get them with flex sections from Buschur. I sure wouldn't have gotten it with a flex section if I knew it was going to hit my diff housing.

 

I would get a different DP. I settled on a tanabe 2.75" to make sure I have clearance. And this is on an '03

 

That is whay I tell everyone to get a DP that uses the stock spring loaded bolts and the stock donut. Using a flex pipe on the EVO is a poor choice due to the tight spot that the dp goes in.

Sell this pipe to some Buschur fanboi and get something else that does not use a flex pipe. I would even get a 2.75 inch dp if I had to do it all over again.

 

I would too, and would still use it even if 400+WHP. Big aftermarket 3" SS DP's conduct heat, and after a good 20 min are at thier radiating capacity.

After a quick drive the DP becomes a 500 degree heater and cooks everything around it - the fluid in the center diff, the oil pan which in some cases touches the DP

 

I would recommend the Megan / TTP 3" DP....Yes it uses the stock donut style gasket....Yes it clears everything fine (even double wrapped -- which I am surprised you have not done)....

I would never remove a cooling fin for a DP (that seems ridiculous).

So in summary, I would HIGHLY recommend a different DP and wrap it....

 

Do you think I could find a decent exhaust shop to cut the flex section out and weld in a straight piece of 3" 304 stainless steel?

 

Im not sure that your exhaust is causing false knock counts...Mine rubs so much on the Tcase that you can here it over the radio between 2000-2700rpms.....no knock here. pound the crap out of the spot and it should fix the rubbing problem.

 

I wouldn't see why they wouldn't do that.

 

Get a better downpipe.

 

I'm sure they could cut out the flex joint and weld in a straight piece to make clearance.

I'll put up another vote for the Megan 3". Mine clears everything just fine (no washers needed on the chassis braces), and it also has a flex joint and donut gasket. I doesn't touch the oil pan, but I bet the advice to add heat wrap is probably not a bad idea.

cij: Did you reuse the stock spring bolts? I wasn't able to get them to thread in, so I used the slightly longer bolts that came with the DP instead.

 

Just trash the thing, not worth breaking parts off your car to fit it