Theoretical max damage Cantrip

Unless I am missing something the Cantrip with the highest theoretical damage is Sorcerous Burst.  It would be almost mathematically impossible (always rolling 8)but with a level 1 soc with chr 16 can cap out at  32 damage (1x8+3x8 burst).  At level 20 chrs 20 it would be 72 damage (4x8+5x8 bust).  (77 on dragon sor.)

Eldritch Blast at 20 chr 20 would do 60 (4x(10+5)). 

Yes EB will do more on normaly (42 vs Sorcerouse burst 18). Can any one top Sorcerous Burst with a cantrip and no other spells only abilities.

P.S. Crit on all would do 104 (8x8+5x8) for SB and 100 (8x10+4x5) EB.

You can get Sorcerous Burst higher than 72 if you're a Warlock who has access to it via Pact of the Tome and takes Agonizing Blast on it, which would add your Charisma modifier to every single damage roll from it. 

It should also be noted that the actual cap on ability scores is 30 (i.e., a +10 modifier) and there are various ways to get your Charisma that high if you're willing to allow the use of multiple epic boon feats, magic items, etc.