cracking vs bang-up

cracking is a noun but bang-up is not a noun.

Word	Noun	Adjective	Verb	Adverb
cracking	Yes	Yes	No	No
bang-up	No	Yes	No	No

As adjectives, cracking and bang-up are synonyms defined as:

Other synonyms of cracking include bully, corking, dandy, great, groovy, keen, neat, nifty, not bad, old, peachy, slap-up, smashing, swell.

cracking (noun)	bang-up (noun)
the act of cracking something
a sudden sharp noise
the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)

cracking (adjective)	bang-up (adjective)
excellent	excellent