It depends on who you ask, some say they have had no issues, some say not worth the risk. They are large enough tho.
I run stock hardlines, on e85 for over a year too. Oh and you arent picking up 30rwhp on an NA. Period.
so stock hardlines has worked for yours. noted. if we arent picking up 30rwhp what are you geussing we will get then? 20rwhp? negative 10rwhp?
Hard to say, I made so many changes all at once. Totally stock the motor made 189kw, I did a heap of bolt ons, turbos, exhaust manis, injectors, rails etc. Turned out 300kw on 98 @ 18psi Turned out 330kw on E85 @ 18psi - this made power all over the range (over 98), not just at the top end.
At the moment around the city I am getting about 300km per tank (on 12psi) On 98, it seems to last forever!
My car when it was NA could advance timing till it lost power without detonation, I'd say 15rwhp at best over an "all out" 98RON tune.