banger vs whizzbang

banger and whizzbang both are nouns.

Word	Noun	Adjective	Verb	Adverb
banger	Yes	No	No	No
whizzbang	Yes	No	No	No

As nouns, whizzbang is a hyponym of banger; that is, whizzbang is a word with a more specific, narrower meaning than banger:

banger: firework consisting of a small explosive charge and fuse in a heavy paper casing
whizzbang: a firecracker that (like the whizbang shell) makes a whizzing sound followed by a loud explosion

Other hyponyms of banger include cannon cracker, cherry bomb, whizbang.

banger (noun)	whizzbang (noun)
firework consisting of a small explosive charge and fuse in a heavy paper casing	a firecracker that (like the whizbang shell) makes a whizzing sound followed by a loud explosion
(British informal) pork sausage	a small high-velocity shell; it makes a whizzing sound followed by a bang when it hits