I have 16x7 45mm back spacing rota slipstreams I'll be putting Hoosier qtp just want to know if I'll need a small spacer?

Thanks

how big of a spacer can you go with out having extended studs

Anything after 5mm you'll need extended studs. You'll need an exact tire size to know what will clear what. Nearly anything on that rim will fit though.

If you're running Hoosier QTP's, I wouldn't run any size spacer on stock lug studs. I'm going to make the assumption you're not putting on drag radials so you can drive the car to work. Although you could typically get away with a 5mm spacer on stock lug studs, I'd upgrade to ARP studs if I were in your position.

http://www.dsmtuners.com/threads/help-with-getting-wheel-spacers.491511/#post-153506877

thanks guys really appreciate the help