These answers don't answer the question, as they no more than repeat the etymology and don't expound Etymonline. So I tried OED, but it also doesn't expound the etymology.
3 Answers
Snorter is first attested by Green's Dictionary of Slang in 1818 meaning "a blow to the nose." By 1828, it is cited in reference to "exceptionally large, strong, [or] violent weather," and eventually also objects and people.
The short answer to this question is the latter sense of "snorter" is, as the OED cross-references, the best etymological clue as to where "rip snort" derives, where rip is referred to by GDoS and the OED as a variant of its use in standard English.
Whether those two senses are connected etymologically as they are somewhat conceptually is an interesting question.
In 1824, "snorter" can be found referring to mortar fire in a rhyming dialectical poem, which predates GDoS's reference to extraordinary weather or objects, and could be seen as a bridge between the notion of a blow to the nose and something extraordinary and large and violent.
There was one thing, I swow! 'twas a snorter,
'Twas raly a curious concern.
They told me, I think, 'twas a "morter"--
There is always something to larn.
If this and other similar citations are a clue, you can trace back "rip-snort" to the notion of "snort" as a sound made by the nose, extended by slang to refer to a strike to the nose, then figuratively extended to the notion of a powerful strike, and onward to simply anything powerful and "of exceptional strength."
A snort is the sound some people make when they are either displeased or laugh loudly at something that they didn't expect was going to be funny. It's an involuntary response, not pretty to hear as it can sound like a pig snorting, but at the same time, it may also provoke hilarity from bystanders or other members of the audience as it is ugly to hear but one or more snorts are often signs of genuine mirth.
To be able to rip a snort from someone who makes snorting sounds, i.e. a snorter, requires great (metaphorical) strength and skill. Thus a ripsnorter is a person, or thing that seizes and pulls (rip) with strength a laugh or indignation from someone.
I'm only kidding.
From Dictionary.com
noun snorter
1. a person or thing that snorts.
2. Informal. something extraordinary of its kind:
a real snorter of a storm.
From Vocabulary.com
snorter
1. n. someone who expresses contempt or indignation by uttering a snorting sound
n. something outstandingly difficult
n. something that is extraordinary or remarkable or prominent
“a snorter of a sermon”
“the storm wasn't long but it was a snorter”
Its first appearance was attributed to Davy Crockett ~1840 (“Of all the ripsnorters I ever tutched upon, thar never war one that could pull her boat alongside of Grace Peabody”). world wide words
Nice short read ... Of Davey AND etymology.