Naruto's fullspeed = shunshin = naruto's footspeed
Sasuke's fullspeed = sharrinengan teleportation jutsu (it has a limited distance) > Sasuke's footspeed.
Conclusion:
Naruto's shunshin > Sasuke's S/T justu (due to his limited distance) > Sasuke's footspeed
Overall:
Naruto's fullspeed > Sasuke's fullspeed
So naruto is faster than sasuke.
P.S: Naruto's shunshin can get even faster with his ashura mode.
Sasuke's fullspeed = sharrinengan teleportation jutsu (it has a limited distance) > Sasuke's footspeed.
Conclusion:
Naruto's shunshin > Sasuke's S/T justu (due to his limited distance) > Sasuke's footspeed
Overall:
Naruto's fullspeed > Sasuke's fullspeed
So naruto is faster than sasuke.
P.S: Naruto's shunshin can get even faster with his ashura mode.