Even if it did have a turbo , I bet they would still be closely matched , the turbo car would be quicker on the straights but I reckon the NA car would be quicker in the bends allowing for lag
A couple of the cars I have mapped have gone from throttle bodied engines to turbo engines, and they have always got faster over a lap on the turbo engines, It does depend a lot on how its mapped and specced though, a crucial element (which ive not yet done on my turbo clio but will do so in the future) is to map the throttle pedal as the boost controller, so that at half throttle you dont still get 99% of the power like on most factory turbo cars, thats the biggest problem with power delivery coming out of bends.
I'd wager even the best possible turbo setup will still lose a couple of mph on every bend though, but if it gains 20mph on every straight that very quickly comes out in the wash IME on a racetrack, although would be a different story down a very twisty B road im sure.
Put it this way though, have you ever seen ANY motorsport class where you are allowed a petrol turbo of the same capacity as an N/A car and without a restrictor on a turbo?
I havent and the reason is they would slaughter the N/A cars by so much it would make it silly.
The only reasons ever to go N/A IMHO are:
Rules say you have to
To keep it very simple on a cheap build