Snowman,

run a 3" downpipe.

3" downpipe tubing. examples:

http://www.ebay.com/itm/MANDREL-BEND-45-...=item5d229db7fd

http://www.ebay.com/itm/3-45-180-Alumini...=item2314ebdd6c

http://www.ebay.com/itm/MANDREL-BEND-45-...=item29f4dcfeaa

http://www.ebay.com/itm/3-45-180-409-Sta...=item2eb8626870

http://www.ebay.com/itm/Vibrant-3-O-D-St...=item2c5b75ae8f

transition for downpipe, does not need to be stainless.
http://www.ebay.com/itm/Vibrant-Stainles...395680276789369

another:
http://www.ebay.com/itm/Steel-2-5-3-Weld...=item5644ebc5ab

What are you going to do for your wastegate exhaust?

You do not need a BOV, right now, but it does reduce excessive pressure applied to the compressor wheel & not allow the excess pressure to go backwards through the compressor housing.

My Syclone did not have a BOV from the factory, & it ran 14 psi stock, the compressor wheel is pretty small & does not get damaged from not having a BOV.

MBHD

12 port SDS EFI