Stromung 2 1/8" (ID) mandrel-bent b-pipe for 91-94 Sentra SE-Rs. Update 4/17/99: (Below is some new info on the Stromung mid-pipe. If Stromung is no longer reachable at the number at the bottom, it's still sounds like a relative deal to go with this Pit Crew company.) ----- It took two months, but I finally received my Stromung B-pipe. If anyone is interested I got it from Pit Crew in California 626-573-1837. I guess Stromung has finally made another batch. Dale Hinson 91 Classic with go fast goodies -- Note: I do not currently have access to my tools - these measurements were not taken with a caliper. I used a tape measure and ruler and tried to be as accurate as possible. My brother double checked and got the same numbers I did. The ID where the pipe bolts to the catalytic converter is 57MM (2 1/4 inch). This diameter is maintained into a straight through resonator. Inside the resonator the "fins" stick out about a 1/4 inch (guessing) from the wall of the pipe on each side, but the fins are spiraled much like the rifling in a gun barrel. Pretty cool - looks efficient. The 57MM is maintained on the other end of the resonator. At about 13.5 inches from where the muffler bolts on, the pipe necks down to 51MM (2 inch). The pipe is painted black and the welds are nice. The pipe feels pretty light as well (no scale available). Overall a very nice piece. The price was $160 + $25 shipping from Pit Crew in California - 626.573.1837. I talked with Mike. BTW, I had to stay in their ear for two months so I would contact them while it is fresh in their minds - I bugged the living crap out of these people. Can't wait to put it on. Dale Hinson 91 Classic getting faster with age ----- Stromung Exhaust engineering 15541 Graham Street Huntington Beach, CA 92649 Voice: 714-890-8052 Fax:714-890-8054 Talk to Scott, he knows about us "SE-R guys from the Internet." I don't think it's stainless, but galvanized. The item # on my invoice is NSR592 $160 with shipping included. (Thanks to Matt Niaura for info)