Yes you will need injectors no matter what you have to keep from leaning out way too much.
You need to spend some time with people that know what to do. I suggest going to
http://www.yotatech.com/ no matter what, and if you really want to do a turbo there have been severial tubro projects on both 3vz-e AND R22's on
http://www.pirate4x4.com/forum/
*edit* whoops didn't read and see you had an R22

Addition
The stock injectors will support 160hp, which is what a stock R22 will push out with a perfect turbo setup @ 6psi. The problem is that is if the injectors are working perfectly AND they're being overworked because they're at 100% duration.
I would swap to atleast 300CC injectors.