Casting bellmouth is cheaper then casting divorced, simple is that.

 

Plus, with economies of scale, casting is actually cheaper than welding pipes.

 

Which branded is casted divorced??? All divorced downpipes i've ever seen for the x have been welded tube.

 

Idk this isnt the old days anymore, they have automated welding

 

I've been looking for awhile now for a good cheap downpipe I came across one from ATP 350 Brand new from them plus shipping from canada big plus is you don't have to worry about a midpipe its a full o2 dump downpipe plus midpipe all in one piece
http://www.flickr.com/photos/54002004@N05/5607926223/what do you guys think?

 

Link to the website http://www.atpturbo.com/mm5/merchant...gory_Code=VEVO

 

anyone running a works downpipe? i have full works TBE with cat. came with the car.

 

Stock DSM, stock VIII, stock IX.

 

note that i said for the X 02 housing . This is a evo X thread correct? Why would we be talking about a different car

 

I never said there was a cast divorced for the X. My theory is Mitsu moving to a cast-bellmouth was a cost-saving measure.

 

Or they took a really old design and made it better

 

Bellmouth is nothing new, Subaru's have been using them for years. You'll also notice some of the nicer aftermarket Subaru downpipes utilize a divorced design.

Both designs work, there is no doubt about that.

 

Its so much easier to weld together pipes than to cast. Obviously little shops are going to weld pipes together than to go with a cast design. I knew there is a reason why i didnt go with a subaru . I should have kept my ets downpipe to show that ams makes more power than any other downpipe. Just think about the design man. Its not complicated. The smaller the pipe, the more back pressure. A huge bell mouth will have FAR less back pressure than two different tubes. Tubulence will not come into play in our case. Does your wife like your stubborn ignorance?

 

Turbulence is indeed a factor, as is the sudden expansion of gas into the bellmouth and then contraction into the o2 housing outlet slows down flow. Keeping the diameter uniform is better. That, combined with separating exducer and wastegate flow makes a well-designed divorced outlet better than a bellmouth.

However, as you said, it comes down to cost.

 

Since you're bringing it up, my car actually showed larger gains on my MAP o2 elim dp than my friend's did with the AMS Widemouth (same dyno, similar setups, etc.). You must also realize that they all become 3" so your "back pressure" theory just went out the window. Turbulence is a huge factor, not sure how you can say it doesn't come into play. How exhaust gasses flow post-turbo does affect how the actual turbo flows air.

Regarding my wife, she is able to understand theories when explained to her...but she does have a bellmouth downpipe on her WRX I'd suggest you keep the personal shots out of this discussion though.