The thread dictates what needle size you want to use in your HQ16 (or comparable LA) I have an innova on a rack and also use Groz-Beckert needles. Below is a handy link to Superior's charts showing which needle sizes they recommend for each thread. I use 14 and 16 mostly (I use mostly Glide thread) but when I use King Tut I go to an 18. If you end up shredding your top thread a lot chances are you need to go to a bigger size needle.
http://www.superiorthreads.com/reference-guides/