SC Impeller Upgrade?

BOLIO 671

Ok guys, I did a google search and couldn't seem to find all the answers I was looking for....

I'm considering the impeller upgrade on the Vortech blower from Stillen...Based on what I've read so far the options are

1). Upgraded impeller from 928 Motorsports in which you can order the Impeller (Counter Clockwise if I'm not mistaken) OR

2). The Vortech Ti or Si Upgrade....

Through my search I found that the Vortech impeller upgrade appears to be cheaper (I beleive AMNVQ quoted around sub $300) versus the 928 Impeller which will run about $600 with shipping. The 928 Motorsports option is pretty clear cut...but how can you order the Vortech upgrade...I've read so many different things...some people posted Vortech won't do it cuz of Stillen and another posted that he was able to get it through communications with both Stillen and Vortech.... I went to Vortech's site and it doesn't have any options about impeller upgrades there....I've also read that if you want to do the impeller upgrade you have to ship the blower out...Is this true for both the Vortech and 928 Motorsports upgrade?

I also wanted to know from those that have experience with these impellers as to which one is better performance wise? I know that the 928 Motorsports site advertises 10-15% more boost throughout the power band, but I couldn't find anything about how much boost/power the Si or Ti impeller upgrade would make....

__________________
2013 Nismo Z34 / FI TT #091 / IG: @lilzilla_z34