So I decided to rewatch the original Friday The 13th, and I've documented the time codes for each death in the movie. For some of the off screen deaths, I've documented both roughly when the character died, and when we see the character's body, as which is considered to be their "Death Scene" might be debatable. So here they are.
Friday The 13th Kill Clock
Robert = Stabbed in the gut at 00:04:40
Claudette = Killed off screen at 00:05:15
Annie = Throat slashed at 00:22:23
Ned = Followed the killer into a cabin at 00:34:25, then is shown hidden in a bunk with his throat slashed at 00:40:10
Jack = Stabbed through the neck while in bed at 00:43:00
Marcy = Takes an axe to the face in the bathroom at 00:46:50
Brenda = Is killed off screen at the archery range, presumably with a bow and arrow, at 00:57:05, and then is thrown through the kitchen window at 01:14:13
Steve = Is stabbed in the gut at 01:04:05
Bill = Is killed off screen out by the emergency generator at 01:07:50, and then is found hanging on the shed door with his throat slashed and shot full of arrows at 01:10:52
* Mrs Voorhees = Decapitated with her own machete on the beach at 01:28:10
(* Mrs Voorhees's death was less an act of terror and more an act of heroism on the part of Alice, which is why I separated it from the others)
So in the original movie, the least amount of time spent building suspense between killings is the roughly 4 minutes in between Jack's and Marcy's deaths. Everyone else gets 10 to 15 minutes to build suspense before each kill. Heck, there's about 17 minutes between Claudette's death and Annie's. Then there's about 20 minutes between Annie's death and the reveal of Ned's dead body.
Some modern horror fans might prefer to have higher body counts with a death or a jump scare every 3 or 4 minutes throughout the entire movie. For me personally? I prefer to get about 10 minutes or so of tension and suspense built up before the payoff of a cool death scene. That, to me, is a great slasher movie.
