X-Pipe Notes and Question(s)

[kyleb350]

After installing a cat back system, I naturally was inquisitive about the rest of the exhaust. Having my car on a lift, I checked out how the cats, O2 sensors, and X-pipe were positioned to see if it's even possible to do a custom setup...who knows?

So it appears that the two sets of cats are before the X-pipe with resonators after. (I was always curious about that)

It makes sense now when I've read people suggesting an aftermarket X-pipe being a good upgrade. It looks like the stock one restricts the flow, and there is also a brace going over it. I see the aftermarket ones, such as Challenge, eliminate the brace and have brackets coming off the pipes (correct me if I'm wrong). I assume that no structural integrity is being comprised when that is done?

[Grail05]

I ran my xpipe without the black bottom brace for rougly 4 months. .. not really needed but BMW felt its safer to run with it.... also most cars have them... well my s2000 had them...

i regret selling my xpipe, i currently have a oem xpipe and damn its too quite...

to get the full potential HP you need to removed the primary cat... its a night and day difference...

my next mod will be a full straight pipe. lets see how that works with my AKRA....

[rockd]

There are 4 cats in the first picture you posted. The two primaries to the very left, then two secondaries, then 2 resonators. I can't speak for other x-pipes, but the Sosi retains the use of the brace.

[hl0m4n]

you guys know if the fabspeed xpipe retains the bracket?

[Ateam]

You can use the bracket with any x-pipe! You simply remove it and place it back on as it is bolted to the frame not the pipe.

This illustrates how really good the OEM exhaust is. Evidenced by really only improving with removal of the primary cats. Otherwise it is a very straight system with no nasty bends or anything to reduce flow. The OEM x-pipe is actually just fine as an x-pipe and changing x-pipes will not do much for power unless you get rid of the cats