Are we going to be pedantic ?
Is your reference to the SLR, the South Link Road ?
Because if it is, then your roads are all mixed up, the South Link Road is the section of the N 27 that runs from The Elysian out to the Kinsale Road Roundabout.
The road you are referring too is the " South Ring Road " Which is mostly the N40, it runs from Dunkettle in the East all the way across the South of the City to the First Exit for Ballincollig where the N40 ends and the road is then the N 22 all the way to Tralee.
As regards speed limits, you are right, coming in from the Ovens side East Bound, the speed limit changes just after the intersection by Dell / EMC, to 120 and it stays at that until you pass the intersection by Marymount in Curraheen where it drops back to 100.