short doesn't an o2 housing.

 

so i keep the stock o2 housing on it with the short or do i just not need an o2 housing?...

 

You need to keep the stock o2 housing, as no one makes an aftermarket one for the RA trubo (that I know of). The o2 housing is actually the biggest restriction in the exhaust system; think of how restrictive the cat is even at 4' from the turbo (maybe 3' or 5', just an estimate), and then place a restriction 6" from the turbine
It's not nearly so bad on the RA, because the turbo is limited by flow anyways (i.e. harder to "clog" with exhaust gases), but like all bolt-ons, every bit helps

 

thank you. so would the UR long downpipe + HFC be a better idea than the short one + hfc?

 

To get every last bit of power you can, yes. It's a personal decision whether the cost is worth the gain. We haven't seen empirical evidence as to how much, but I would expect mid-rpm-range improvements to be the biggest gain.

 

Send me your stocker...

 

may be a real dumb question but would a boost controller help protect from running rich or lean?...