With just a few bolt ons (gutted airbox, 3" catless dp, tstat, powrtuned, basic race prep, little stuffs) my '99 GT would run consistent 15.2's @ 90/91 at the track. Not too far off from a stock GTP (14.8's @ 93). Mod for mod there's no comparing na to fi, though, naturally. Was a 3400 lb race weight, as well (coupe with 1/8 tank of gas and spare/jack removed)