I have been looking for better spoolup on my truck ever since I swapped to a 5 speed. I finally put a wastegated 12 cm housing on my truck. The wastegate is pinned shut. I peak out at 33psi on #2 only. With the 16, I could only manage 29 psi. My truck is quieter at idle and now the turbo barks like nothing else. I dont loose as much boost between shifts...but my truck honestly feels the same as far as power goes. In fact, I dont think the 12 spools significantly faster and top end power is about the same as well. I havent seen any downsides yet either though...my egts are actually the same. Since I got the housing for free, im going to try it out over the weekend and if i dont like it, ill put my 16 back on. If some of you have some wisdom to share, id like to hear it.

 

dont know where you live, im probably at higher elevation, smaller housing works great for me. ive noticed better fuel economy as well. the 12 is a better match on the hx

 

I never really noticed a huge difference between my 12 and 16 on the hybrid. Of course I had the center divider cut on completely on the 12 so that may have had something to do with it.