I just recently returned my R55 back to stock. Today I took off the Forge Intercooler and the NM Engineering Hot and Cold side boost tubes. I reinstalled the stock tubes including the noise-maker. The problem I am having seems silly, but for the life of me I must be missing something. Looking at the realoem image below, I am having an issue with the joint between tube "7" and "8". The connection here is a metal sleeve that allows the "7" tube to fit into tube "8" with a collar. It looks like it would be an "insert and twist" type of fitting but for some reason I cannot get this to "seat" correctly. There are two small notches on the "7" tube that fit an inset into tube "8"'s collar, but it doesn't turn at all. Am I just not giving it enough pressure? I have tried twice now and both times once I give it some good acceleration that joint pops off.

Any ideas?

 

Well I found my issue. When I compared the tubes to my R58, I noticed that tube #8 has a retaining clip around the collar that secures the metal sleeve that exists on tube #7. I am missing that retaining clip and its nowhere to be found. Apparently you can't get a replacement clip, you must order the entire tube... Looks like I'll just swap the stock one off my R58 for now and put the NM pipe on in its place.

 

there is a metal clip (its c shaped with tabs at end points on the c that face down) that is the locking collar to keep the upper u-coupler connected to the y-piper (plastic piece between noise maker connection and coupler to throttle body. if your the c-clip it will not lock into place and will float and pop off. i bet thats the part your missing.