I'll enter race and end up a wreck (4)
I believe the answer is:
ruin
'a wreck' is the definition.
(I've seen this in another clue)
'i'll enter race' is the wordplay.
'i'll' becomes 'i' (this might be a standard abbreviation of which I'm unaware).
'enter' indicates putting letters inside.
'race' becomes 'run' (running is a kind of racing).
'i' going within 'run' is 'RUIN'.
'and end up' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for ruin that I've seen before include "Destroy; downfall" , "Wrecked building" , "Dilapidated building" , "Destroy completely" , "Utter destruction or downfall" .)