Welcome to my listing.  I am offering for sale a set of 6 velocity stacks for the BMW S54 engine.  These are new old stock parts made by BMW with part number 7831251.  These were acquired from a OE supplier as the trumpets were never sold individually and as such the part number is not in the parts catalogue.  

I only have one set left of the 4 sets I had, I will not be able to get more.

This is a fraction of the cost of the PSDesign velocity stacks.  Priced per set of 6.  On the picture one set is missing the lock rings, but I do have them.